NARDA NBM-550 Operating Manual Download Page 1

NBM-550

Narda Broadband Field Meter

Operating manual

Distributed by:

Air-Met Scientific Pty Ltd

Work with Confidence

Air-Met Sales/Service

 

P: 1800 000 744 

F: 1800 000 774 

E: [email protected]

Air-Met Rental

 

P: 1300 137 067 

E: [email protected] 

W: www.airmet.com.au

Summary of Contents for NBM-550

Page 1: ... Meter Operating manual Distributed by Air Met Scientific Pty Ltd Work with Confidence Air Met Sales Service P 1800 000 744 F 1800 000 774 E sales airmet com au Air Met Rental P 1300 137 067 E hire airmet com au W www airmet com au ...

Page 2: ...der no 2401 98 21 Version 06 15 03 A Previous version 05 11 03 A Subject to change Our normal guarantee and delivery terms apply Printed in Germany This product is protected by the following patents China Design Patent ZL 2006 3 0303322 X China Design Patent ZL 2006 3 0190679 1 European Design Patent 000594254 001 European Design Patent 000597836 0001 German Patent DE19536948A1 U S Design Patent N...

Page 3: ... Terminology 6 2 Safety instructions 7 2 1 Using this operating manual 8 2 2 Proper use 8 2 3 Improper use 8 2 4 Dangers from electromagnetic fields 9 Strong Fields 9 Measurement Errors 9 Probe is not operating properly 9 2 5 Dangers when handling rechargeable batteries 10 2 6 Dangers from AC Adapter Charger 10 3 Preparing the NBM 550 for use 11 3 1 Unpacking 12 Packaging 12 Items included 12 Unpa...

Page 4: ... coupling connector 25 3 6 Connecting and setting up the EHP 50 26 3 7 Fitting the GPS module 27 3 8 Using the table top tripod 27 4 Getting started 29 4 1 Switching on 30 Self test 30 Calibration 30 EHP 50 31 GPS reception 31 4 2 The NBM 550 operating concept 32 Measurement screen overview 32 The menu levels 33 Navigating in the menus 34 4 3 Making basic settings 35 Selecting the language 35 Sett...

Page 5: ...ype 46 Freezing a measured value 47 Storing a measured value 47 Add voice comments optional 48 Setting the averaging time 49 5 3 Measuring the spatial average 49 Measuring discrete values 50 Measuring values continuously 51 5 4 Measuring in History display mode 52 Display overview 52 Evaluating the curve 53 Storing the graphical record 54 5 5 Measuring in XYZ display mode 54 Display overview 55 5 ...

Page 6: ... 68 Freezing a measured value 68 Storing a measured value 68 6 4 WPM display mode Weighted Peak method 69 6 5 Spectrum display mode 71 6 6 Standard display mode 73 6 7 XYZ display mode 74 6 8 Monitor display mode 74 6 9 Other settings 75 Unavailable functions 75 The alarm function 75 Storing measured values 75 Managing result data 77 Saving and loading device settings 77 7 Recording and managing m...

Page 7: ...Setting the power on behavior 92 8 3 Displaying instrument and probe information 92 8 4 Using the NBM 550 as a controller 93 8 5 Activating instrument options 94 9 PC software 95 9 1 Using the PC software 96 Minimum system requirements 96 9 2 Connecting the NBM 550 97 9 3 Working with the PC software 97 9 4 Updating the firmware 98 9 5 Performing a reset 99 10 Overview of all menus and functions 1...

Page 8: ... 117 11 3 Disposal 119 Rechargeable batteries 119 Instrument 119 11 4 Checking instrument functions 120 Appropriate test sources 122 12 Specifications 123 12 1 Display 124 12 2 Measurement functions with HF probes 124 12 3 Result memory 125 12 4 Interfaces 125 12 5 Options 126 12 6 General specifications 127 12 7 Standards compliance 128 12 8 AC Adapter Charger 128 12 9 EHP 50 128 12 10 CE Declara...

Page 9: ...Contents Narda NBM 550 VII 13 Ordering information 133 13 1 NBM 550 134 13 2 Probes 134 High frequency probes 134 Low frequency probes 135 13 3 Accessories 135 14 Glossary 137 Index 141 ...

Page 10: ...Contents VIII NBM 550 Narda ...

Page 11: ...ation about measuring electromagnetic fields about using the NBM 550 and about the structure of this operating manual 1 1 Measuring electromagnetic fields page 2 1 2 About the NBM 550 page 2 1 3 About the EHP 50 Analyzer option page 3 1 4 About this operating manual page 4 ...

Page 12: ... utmost accuracy within the frequency range from 100 kHz to 60 GHz depending on the probe used The instrument has a wide range of functions yet it is very easy to use It also features a handy design robust casing long battery life and high measurement accuracy Probes for various measurement applications are connected to the NBM 550 basic unit Flat frequency response probes are available as well as...

Page 13: ...g equipment Measurements to ensure the safety of persons using diathermy equipment and other medical equipment that generates high frequency radiation Field strength measurements in TEM cells and absorber chambers 1 3 About the EHP 50 Analyzer option The optionally available EHP 50 Analyzer can be used to measure either electric or magnetic fields in the frequency range between 1 Hz and 400 kHz As...

Page 14: ... on the NBM 550 and easily carry out most of the measurement tasks using HF probes in chapters 3 to 5 and 7 to 9 2 Measuring with the EHP 50 Analyzer You will find all the information you need to operate the EHP 50 LF Analyzer in conjunction with the NBM 550 in chapter 6 Cross references are provided to information already described in other chapters 3 Overview of menus and their functions You wil...

Page 15: ...arns of risk of serious injury when used with the signal words CAUTION WARNING and DANGER Follow all the instructions in order to avoid injuries or death NOTICE Indicates a danger that results in damage to or destruction of the instrument CAUTION Indicates a hazardous situation which if not avoided could result in minor or moderate injury WARNING Indicates a hazardous situation which if not avoide...

Page 16: ...ruction Indicates a single instruction e g Switch the instrument on 1 2 3 Sequence of instructions Indicates a sequence of instructions that must be carried out in the order given Result Indicates the result of carrying out an instruction e g The instrument starts a self test Bold type Control element Indicates a control element on the instrument e g Press the ENTER key CAPITALS Menu name Indicate...

Page 17: ...y Please therefore read this chapter carefully and follow the instructions closely 2 1 Using this operating manual page 8 2 2 Proper use page 8 2 3 Improper use page 8 2 4 Dangers from electromagnetic fields page 9 2 5 Dangers when handling rechargeable batteries page 10 2 6 Dangers from AC Adapter Charger page 10 ...

Page 18: ...n particular observe the technical data given in the Specifications on page 123 Proper use also includes observing any national accident prevention regulations at the place of use ensuring that the instrument is used only by appropriately qualified and trained persons 2 3 Improper use The NBM 550 is not a warning device that gives active notice of the existence of dangerous fields by means of a vi...

Page 19: ...haft If the instrument malfunctions take it out of service and contact your Narda Service Center The addresses are listed at the end of this operating manual and on the Internet at http www narda sts com Probe is not operating properly Possibly present high radiation values are not recognized Check probes for proper operation with a signal source before using this measuring instrument This is espe...

Page 20: ...artment immediately after replacing batteries Never use the NBM 550 with the battery compartment open 2 6 Dangers from AC Adapter Charger You could experience electric shock from the AC adapter charger Do not use the instrument when the casing is damaged because parts carrying dangerous voltages could be exposed Do not use an AC adapter charger that has been moved from a cold to a warm room thereb...

Page 21: ...tarting to use the NBM 550 3 1 Unpacking page 12 3 2 Instrument overview page 16 3 3 Power supply NBM 550 page 20 3 4 Power supply EHP 50 page 23 3 5 Connecting the probe page 24 3 6 Connecting and setting up the EHP 50 page 26 3 7 Fitting the GPS module page 27 3 8 Using the table top tripod page 27 ...

Page 22: ...delivered NBM 550 NBM 550 4 x NiMH Mignon AA batteries packaged separately Case Probe type and quantity as ordered AC Adapter Charger Shoulder strap USB cable Table top tripod CD ROM with NBM TS PC software Operating manual Calibration certificate EHP 50 Set for NBM 550 EHP 50 Analyzer 12 V AC DC charger Optical connector bridged for stand alone operation Extension rod 0 5 m Optical cable 10 m O E...

Page 23: ...ny degradation due to moisture and means that the recommended calibration interval can be increased by as much as 6 months This is intended to ensure that the recommended period of use of 24 months can still be achieved even if delays occur in transit or due to customs procedures Transport damage The addresses of your Narda Service Center are listed at the end of this operating manual and on the I...

Page 24: ...e lid and case base Case lid Case base 1 Test generator 2 Probe 3 O E converter USB 4 GPS fitting set 5 RadMan Personal Monitor 6 Compartment for cables and operating manual 7 O E converter RS232 8 Extension rod 2 2 2 1 6 5 4 3 7 8 1 NBM 550 basic unit 2 GPS assembled 3 Rechargeable batteries 4 AC adapter 5 Table top tripod 6 Probe or EHP 50 with foam inlays 7 NBM 520 basic unit 8 Shoulder strap 9...

Page 25: ...the operating range of 10 to 50 C NOTICE Condensation on an instrument can lead to damage Condensation can form on an instrument that has been stored at a low temperature when it is brought into a warm room It may be damaged if used Wait until all visible condensation has evaporated from the instrument surface to avoid damaging the instrument ...

Page 26: ...3 Preparing the NBM 550 for use 16 NBM 550 Narda 3 2 Instrument overview NBM 550 Figure 1 Device overview NBM 550 1 3 4 5 2 6 8 7 6a 6b 6c 6d ...

Page 27: ...ad change the contrast ON OFF key Used to switch the instrument on or off Charge Charge state Indicates the charge state red rapid charging green trickle charging Status Operating status Indicates the instrument operating status Green normal operation red remote operation flashing red firmware update or exceeded alarm threshold 5 Tripod bush 6 Electrical and optical connectors 6a Multi function so...

Page 28: ...3 Preparing the NBM 550 for use 18 NBM 550 Narda Probes Figure 2 Overview of probes 9 10a 12 13 11 13a 13c 13e 13d 13b 10b ...

Page 29: ...can only be used with EHP TS Please follow the instructions in the EHP 50 operating manual 13c ON OFF button 13d Status LED Meanings of colors and flashing rates No charger unit connected Red rapid flashing cannot set up communications Green rapid flashing setting up communications Green slow flashing data transfer in progress flashing rate depends on measurement speed Charger unit connected no da...

Page 30: ... using the device The charging cycle takes about 2 hours Do not use dry batteries in this device Inserting the batteries 1 Open the battery compartment cover underneath the device by undoing the two screws with a screwdriver or the edge of a coin 2 Take the NiMH batteries provided out of their protective foil and insert them into the battery compartment Make sure you put them in the right way roun...

Page 31: ...ration usually takes four to five recharging cycles Note A complete charge cycle takes about 2 hours with the instrument switched off Starting the charge cycle The AC line voltage must match the operating voltage of the AC Adapter Charger 1 Connect the AC Adapter Charger to the charging socket of the NBM 550 2 Connect the AC Adapter Charger to the AC line The charge cycle starts The Charge LED glo...

Page 32: ...n the meantime Avoid deep discharging the batteries as this could cause the cells to reverse polarity and make them useless Charge state and power source indicator The battery charge state and the power source used are indicated at the top right of the display Table 1 Charge state and power source indication Power is supplied by the rechargeable batteries Continuous display Charge level 10 Flashin...

Page 33: ...e AC line voltage must match the operating voltage of the charger unit Connect the charger unit to the AC line first and then connect it to the charger socket on the EHP 50 Figure 2 13d The charging cycle starts and the DATA LED flashes rapidly Orange battery charging Green battery fully charged Note You can charge the battery with the EHP 50 switched on or off If you connect the charger unit when...

Page 34: ... applications for the NBM 550 You can find more information about the order numbers and specifications of the probes under Ordering information on page 133 as well as in WARNING Probe is not operating properly High radiation values that may be present cannot be recognized when a probe is defective Check probes for proper operation with a signal source before using this measuring instrument This is...

Page 35: ...evices use threaded connectors for the link between the probe and the basic unit The basic unit is fitted with a longer socket which can be recognized by the approximately 1 cm long threaded section Probes fitted with push pull connectors can still be used with this connector Probes with threaded coupling connectors can only be used with this new longer connecting socket Connecting the probe Make ...

Page 36: ...only fit in one direction and will lock in place when light pressure is applied 2 EHP 50D Plug the white plug of the optical cable into the optical connector of the EHP 50 Figure 2 13a The plug nose must be aligned with the indentation on the socket or EHP 50F Plug the black plug of the optical cable into the optical connector of the EHP 50 with the groove of the grip pointing towards the center o...

Page 37: ...y be used with NBM 550 devices for which a GPS option was ordered and activated see Activating instrument options on page 94 When reordered activation is carried out via the supplied activation code contained in the Options Passport Document 3 8 Using the table top tripod A table top tripod is included with the NBM 550 This makes the instrument easier and more convenient to use Attaching the tripo...

Page 38: ...3 Preparing the NBM 550 for use 28 NBM 550 Narda ...

Page 39: ... 4 Getting started This chapter describes how to switch on the NBM 550 the operating concept and the initial settings 4 1 Switching on page 30 4 2 The NBM 550 operating concept page 32 4 3 Making basic settings page 35 ...

Page 40: ...ch it on again If an error message is displayed again Switch the instrument off and contact your nearest Service Center Calibration The NBM 550 and probes must be calibrated at certain intervals to guarantee the quality of the measurement results If you have missed the date for a calibration this will be displayed by default after the self test is complete Note You can deactivate the calibration d...

Page 41: ...g System When the GPS module is connected the coordinates along with other information are shown in the upper section of the display If GPS cannot be received despite a GPS module connection e g in closed rooms Lat and Lon are displayed without appropriate values If GPS was received but suddenly interrupted e g due to poor signal quality or an unplugged GPS plug the most recent available coordinat...

Page 42: ...0 Measurement screen overview The description below gives you an initial overview of the display elements in the measurement screen display Other elements are described in the chapters dealing with the individual functions and in the Overview of all menus and functions on page 101 1 Probe used also shows the EHP 50 battery charge state and the selected frequency range if the EHP 50 is used 2 Alarm...

Page 43: ...se that are used less often 1st level The measurement screen 2nd level The main menu 3rd level The sub menus 4th level The functions The measurement screen You can directly activate a function or make a selection by pressing one of the four function keys in the measurement screen All other settings have to be made using the menus described below The main menu The MAIN menu opens when you press the...

Page 44: ... You can then make the settings you require or read out the desired information The example shows Timer Start Navigating in the menus Use the following keys to navigate through the menus and select the functions Function keys Select the function shown in the display which depends on the menu selected ESC key Exits from the menu with or without making changes OK key Opens a menu or a function and c...

Page 45: ...lected see Saving and loading instrument settings on page 90 Selecting the language You can set the user interface language to a different language Changing the user interface language 1 Open the Language function MAIN MEASUREMENT SETTINGS 2 Use the arrow keys to select the desired language and then press the OK key to confirm the setting Setting the auto zero adjustment Zeroing compensates for th...

Page 46: ...Setting the auto off function You can set the instrument to switch off automatically after a specified time without any activity to protect the batteries from being discharged The following settings are possible 6 15 30 60 minutes Switches off after 6 15 30 60 minutes off Auto off function disabled The default setting is 15 minutes Note The auto off function is disabled during long term measuremen...

Page 47: ...g the contrast The display shows the measurement screen Press the arrow keys or to increase or decrease the contrast Changing the display units Power density or field strength units can be selected when using normal flat probes The units can simply be converted while the measurement will stay the same Results from shaped probes are always displayed in A shaped probe provides a frequency sensitivit...

Page 48: ...he measured value 47 55 μW cm2 in the example shown on the left Tip We recommend that you use the Variable Triads format for signals that have a high dynamic range otherwise the display of very small or very large values will be meaningless Changing the units format 1 Open the Results Format function MAIN MEASUREMENT SETTINGS Next 2 Use the arrow keys to select the desired format and then press th...

Page 49: ...you choose the 12 hour time format you must also select AM or PM press the OK key to confirm the selection 4 Set the date format Select the Date Format function use the arrow keys to select the format mm dd yyyy dd mm yyyy yyyy mm dd and press the OK key to confirm the selection 5 Set the date Select the Date function use the function keys to select the day month or year and use the arrow keys to ...

Page 50: ... the Combi Probe Use function MAIN MEASUREMENT SETTINGS Next 2 Use the arrow keys to select the desired format E Field and H Field E Field only H Field only 3 Press the OK key to confirm the selection Setting the units 1 Select the E H Field Units function MAIN MEASUREMENT SETTINGS Next 2 Use the arrow keys to select the desired units Selected Unit The units selected using the Unit function key wi...

Page 51: ...ng the keypad To prevent inadvertent operation of any of the keys you can lock the keypad Locking the keypad Press the two arrow keys simultaneously The message KEY LOCK is displayed Unlocking the keypad Press the two arrow keys simultaneously again ...

Page 52: ...4 Getting started 42 NBM 550 Narda ...

Page 53: ...e menus and functions under Overview of all menus and functions on page 101 5 1 Avoiding measurement errors page 44 5 2 Measuring in Normal display mode page 46 5 3 Measuring the spatial average page 49 5 4 Measuring in History display mode page 52 5 5 Measuring in XYZ display mode page 54 5 6 Measuring in Monitor display mode page 56 5 7 Activating the alarm function page 57 5 8 Audible Indicator...

Page 54: ...be displayed which do not reflect the actual field conditions This effect is caused by electrostatic charges The NBM has been designed in a way that minimizes this effect However if you move the probe very quickly field strengths on the order of a few V m can be displayed Recommendation Hold the device steady during the measurement Delete the stored maximum values and average values by pressing Cl...

Page 55: ... of band attenuation is 20 dB decade A probe specified to measure from 100 kHz to 3 GHz would therefore attenuate signals down to 100 Hz by at least 60 dB field strength 1000 However very high field strengths of several thousand V m can occur in the vicinity of high tension lines An RF wideband probe would therefore register several V m Recommendation Thoroughly inspect every measurement location ...

Page 56: ...aging time in the MEASUREMENT SETTINGS Averaging Time menu see Setting the averaging time on page 49 The bar graph disappears once the first average value has been determined The average result is then valid As the measurement continues the average is formed continuously using the results obtained during the time window averaging time Press the ESC Clear key to reset the display value to 0 Max Avg...

Page 57: ... a measured value Press the Store key The measured value displayed at the moment is stored with the date and time under the index number displayed The remaining memory space is also dis played You can also trigger storing of measured values using an external signal Storing measured values using an external trigger 1 Open the External Trigger function MAIN INTERFACE 2 Use the arrow keys to select t...

Page 58: ...omment You have just stored a measured value The message Voice recorder enabled is displayed when voice recording has been enabled In case you do not want any comments Press Cancel Record In case you want to record a comment 1 Press the Start Record function key and speak the comment Speak in the direction of the microphone above the display from a distance of 20 to 30 cm and speak loudly enough s...

Page 59: ...average of the field strength using the Spatial Average function This function is used to determine the exposure to electromagnetic radiation of the human body for example Two measurement methods are available Discrete Individual results are recorded and averaged You can measure at specific locations using this method Continuous Results are recorded and averaged continuously during the time that t...

Page 60: ...surements is shown after Pos 1 4 When you have recorded all the measured values you can either add positions so you can record more results e g at different locations or you can store the entire measurement Adding a position 1 Press the Add Position key Pos 2 is displayed The result counter shows 0 2 Record new measured values as described above 3 You can add more positions and record more results...

Page 61: ...rther average values or store the entire measurement Note The NBM 550 emits an audible signal every second to assist you in moving it evenly Adding a position 1 Press the Add Position key Pos 2 is displayed the elapsed time counter shows 00 00 s 2 Record new measured values as described above 3 You can add more positions and record more results if necessary Avg Pos shows the average value for all ...

Page 62: ...ote The progress memory is always active As a result a valid curve already appears when changing to History mode It will be deleted however as soon as you change a parameter that affects the measurement result e g correction frequency or time span The rolling measurement memory deletes all values that date back longer than the set time period Display overview 1 Defines the Y axis display range as ...

Page 63: ...on was made Interval shows the display resolution cursor step size 3 Press the function keys to move the cursor to the left or right or press the Highest Peak function key to move the marker to the highest measured value 4 Press the Marker OFF function key to switch off the cursor 5 Press the Release function key to unfreeze the display The measurement record and curve are updated to show the chan...

Page 64: ...ed 5 5 Measuring in XYZ display mode In XYZ display mode the measurement values of the three spatial axes as well as the isotropic field strength calculated from them are displayed simultaneously Note XYZ display mode is not available for all probe types If the probe you are using does not support XYZ mode it will not be available for selection Changing to XYZ display mode The display is in measur...

Page 65: ...lay area 2 Display of the RSS root sum square field strength value calculated from the X Y and Z values valid for units V m and A m linear addition for mW cm2 and W m2 3 Graphic display of field strength showing the selected field type E field in the example shown here 4 Only the latest measured values for each axis can be shown result type Actual 5 Measured values for the three axes 6 The Result ...

Page 66: ...and determination of the maximum average and minimum values starts immediately Display overview Resetting the values shown in the lower display area Press the ESC Clear key 1 Field strength result type shown in upper display area 2 Display of latest field strength value 3 Remaining averaging time 4 Graphic display of field strength showing the selected field type E field in the example shown here ...

Page 67: ...limit values in 1 dB steps Shaped probes 0 1 10 000 in 1 dB steps Defining the alarm limits 1 Open the Alarm Limit function MAIN MEASUREMENT SETTINGS 2 Use the arrow keys to change the value and press the OK key to confirm the setting Activating the alarm function 1 Open the Alarm Function function MAIN MEASUREMENT SETTINGS 2 Use the arrow keys to select On and press the OK key to confirm the sett...

Page 68: ...ing 5 9 Measuring with a test standard The NBM 550 allows measurement based on test standards in the NORMAL display mode Since the measurement result refers to a single defined frequency in contrast with the usual broadband measurements measuring with a test standard only makes sense if the field you want to measure is dominated by a known frequency You can apply a test standard as follows Use a s...

Page 69: ...ibrated at these frequencies or enter a frequency value of your choice Using a calibrated frequency 1 Press the or arrow key The measuring frequency is set to the next higher or next lower calibrated frequency 2 Press the OK key to confirm the setting and then use the ESC key to exit from the menus Entering a frequency manually 1 Press the Edit function key 2 Select the digit using the function ke...

Page 70: ...st standard Probe type E H Field Units Display only in NORMAL mode Upper area Lower area E field or H field flat Measured value shown with selected units Selected standard Value in calculated according to the standard and frequency E field or H field shaped Measured value in Probe standard Value and selected units calculated according to the standard and frequency Combination probe flat V m and A ...

Page 71: ...plays Probe type E field flat probe Probe type E field shaped probe Probe type Combination E field and H field flat probe Combi probe uses V m A m Note The S field is shown in the upper area of the display as the product of the magnitudes of the E field and H field ...

Page 72: ...cy to enhance the accuracy of the measurement Ideally the calibration frequency and the measuring frequency should be identical However any intermediate value with a resolution of 1 kHz which is calculated from the bordering calibration frequencies using interpolation can also be set Selecting the correction frequency Open the Frequency function MAIN MEASUREMENT SETTINGS 1 Press the or arrow key T...

Page 73: ...erated as a stand alone FFT analyzer You can find information on how to operate it along with further important information in the Operating Manual for the EHP 50 which is provided as a PDF file on the EHP TS PC software CD 6 1 General information page 64 6 2 Display types page 65 6 3 General settings page 66 6 4 WPM display mode Weighted Peak method page 69 6 5 Spectrum display mode page 71 6 6 S...

Page 74: ...not yet support the Weighted Peak method Selecting EHP 50 mode manually When starting up the NBM 550 recognizes an EHP 50 connected to it if this has already been switched on see Connecting and setting up the EHP 50 on page 26 EHP 50 operating mode will be selected automatically after initialization has completed successfully if there is no HF probe connected to the NBM 550 HF probes have priority...

Page 75: ...d wideband from 1 Hz to 400 kHz with graphical display of time characteristic See WPM display mode Weighted Peak method on page 69 Spectrum X Graphical display of field strength versus frequency Numerical display of the wideband value or the highest spectral line See Spectrum display mode on page 71 Standard X Graphical display as Spectrum mode but with the measured values referred to the limit va...

Page 76: ...mode Display wideband or peak value You can display the numerical value referred to the wideband measurement or to the peak value To switch the display 1 Open the Frequency mode function MAIN MENU MEASUREMENT SETTINGS 2 Use the arrow keys to select the desired setting and press the OK key to confirm 3 Press the ESC key twice to return to measuring mode Changing the field type and measurement range...

Page 77: ... to confirm 3 Press the ESC key twice to return to measuring mode Changing the result type Different result types are available depending on the display type The table below gives an overview Maximum The maximum measured value is retained You can reset the maximum value and restart the measurement by pressing the ESC key Result type ACT Actual MAX Maximum AVG Average MIN Minimum Monitor1 X X X X X...

Page 78: ... ESC key twice to return to measuring mode Changing the frequency range Span You can select the following frequency ranges 100 Hz 200 Hz 500 Hz 1 kHz 2 kHz 10 kHz 100 kHz or 400 kHz The frequency range for WPM is fixed at 1 Hz to 400 kHz Use the arrow keys to change the Span Freezing a measured value This function is the same as the measurement with HF probes See under Freezing a measured value on...

Page 79: ... since you only have to select the relevant safety standard The device then supplies the measured value as a percentage of the limit value The EHP 50F performs the Weighted Peak method with mathematical convolution in the time domain to conform with ICNIRP 2010 and IEC 61786 2 The measurement covers the entire frequency range from 1 Hz to 400 kHz A graph shows the time characteristic of the measur...

Page 80: ...at the cursor position Time Time the measurement at the cursor position was made 3 Use the function keys to shift the cursor to the left or right or press the Highest value function key to move the marker to the highest value 4 Press the Marker OFF function key to remove the cursor from the display 5 Press the Continue function key to unfreeze the display The recorded measured values and the graph...

Page 81: ...ed value recording 1 Press the Hold key to freeze the display 2 Press the Save History function key The measured value recording is saved You can add a voice comment if you have activated this function 6 5 Spectrum display mode Spectrum display mode displays the field strength versus frequency values graphically and numerically 1 4 3 2 1 Result type and numerical display of field strength or marke...

Page 82: ...OFF when the marker function is active The marker is shown as a horizontal and a vertical line The numerical value of the marker is shown in the upper display window 2 Use the function keys to shift the marker to the left or right 3 Press the Highest value function key to move the marker to the highest value on the trace Other functions The other functions are the same for all display modes and ar...

Page 83: ...active The marker is shown as a horizontal and a vertical line The numerical value of the marker is shown in the upper display window 2 Use the function keys to shift the marker to the left or right 3 Press the Highest value function key to move the marker to the highest value on the trace Other functions The other functions are the same for all display modes and are described under General settin...

Page 84: ...tor display mode shows the numerical actual maximum average and minimum measured values simultaneously Other functions The other functions are the same for all display modes and are described under General settings on page 66 1 Numerical display of the actual measured value 2 Wideband or frequency of the highest field strength 3 Graphical display of field strength with indication of the selected f...

Page 85: ...tion The alarm function can be used without any restrictions See Activating the alarm function on page 57 Note The alarm thresholds for HF and LF modes are saved separately in a setup This also applies to the E field and H field thresholds in LF mode Storing measured values You can only record wideband values or highest spectral values using timer controlled storage in LF mode with the EHP 50 It i...

Page 86: ...ogging results obtained in LF mode can be subsequently averaged using the optionally available NBM TS PC software RMS MEAN and MEDIAN post average evaluations are available Note Since uninterrupted measurement is not possible in LF mode except for WPM the measurement results are not summarized into Min Max Avg values for each measurement interval The Actual values are recorded once every interval ...

Page 87: ...lay mode LF3 XYZ display mode LFM Monitor display mode LFT Timer Logging storage type WPV Weighted Peak value single measurement WPH Weighted Peak history values versus time Saving and loading device settings You can save and recall your device settings in a setup in the same way as in HF mode All EHP 50 specific settings are saved separately This also applies to the selected standard See Saving a...

Page 88: ...6 Measurements with the NBM 550 and EHP 50 78 NBM 550 Narda ...

Page 89: ...ment values automatically Data Logger and how to recall and manage the measurement data that you have recorded manually or automatically 7 1 Storage types page 80 7 2 Recording measurements by timer control page 80 7 3 Recording conditional measurements optional page 82 7 4 Managing result data page 84 ...

Page 90: ...easurements optional on page 82 7 2 Recording measurements by timer control For timer controlled recordings measured values are recorded without interruption within the specified time period and are combined in 3 values per measurement interval minimum value maximum value and average of the measurement interval The averages can be very easily converted subsequently to other averaging times with th...

Page 91: ...nd use the arrow keys to change the value press the OK key when you have completed the settings to confirm them 4 To enter the recording interval open the Timer Interval function select a digit using the function keys and use the arrow keys to change the value press the OK key when you have completed the settings to confirm them Started measurement intervals are always carried out to completion Th...

Page 92: ...ped after the preset recording duration Timer Duration has elapsed Note The recording starts immediately when Instant Start is selected The recording can be prematurely stopped at any time with the Stop and Exit button 7 3 Recording conditional measurements optional For conditional recording the measurement is triggered when the predetermined field strength values are exceeded or fallen short of U...

Page 93: ...nter the lower threshold only effective at OUT of Gap open the Lower Threshold function select the threshold value with the arrow keys only effective at OUT of Gap and press the OK button to apply the settings Parameter Meaning Store Condition Specifies the condition for starting recording Upper THRHLD upper threshold The recording starts if the Upper Threshold value is exceeded Out of GAP The rec...

Page 94: ... values measured that fulfill the condi tion is displayed Number of Events 3 Press the Exit function key to end the recording 7 4 Managing result data There are two menus provided for you to display and delete measurement data that you have recorded either manually or automatically Memory Manager MAIN MEMORY MANAGER Data Viewer MAIN Data Viewer function key The differences between these menus are ...

Page 95: ...e list of all stored data opens Table 5 Column meanings Column Function Index Consecutive number identifying the data se Number of stored sub data sets within a measurement series max 32000 always 1 for manually stored results since only one data set is stored each time A maximum of 999 sub data sets can be displayed on the device intervals or events The NBM TS PC software enables complete evaluat...

Page 96: ...xamples of the possible contents of the measurement data memory are shown below Results are shown in the same format as for the measurement itself Example 1 Manual storing Example 2 Timer Logging Display Meaning Values Monitor display mode E field Data Viewer Display is in Data Viewer mode Monitor Measurement values were saved in the Monitor display mode Index 0002 The values were stored at memory...

Page 97: ...layed back Display Meaning Values Conditional display mode Meaning of the status indicators on the First and Last Storage Range F First first measurement value in which the condition is fulfilled L Last last measurement value in which the condition is still fulfilled no change neither to F nor L only with combination probes Meaning of the status indicators Store all on the Storing Range Y Yes meas...

Page 98: ... managing measured values 88 NBM 550 Narda Deleting a data set Note You can only ever delete the last entry in the memory The overview list is open Press the Delete Latest function key The last latest entry is deleted ...

Page 99: ...nd settings as well as for use of the NBM 550 as a controller and for the activation of new instrument options 8 1 Configuring the interface page 90 8 2 Saving and loading instrument settings page 90 8 3 Displaying instrument and probe information page 92 8 4 Using the NBM 550 as a controller page 93 8 5 Activating instrument options page 94 ...

Page 100: ...ngs setups and recall them when you need them again Nine memory positions are provided for such settings so you can save setups for different measurement tasks or for different users for example Note You can use the NBM TS PC software to store the setups completely in the database and upload them to the instrument again when they are needed Menu overview Open the MAIN SETUP menu Default These sett...

Page 101: ...ress the Load function key The instrument settings are restored loaded Saving a setup You can only store your own setups in memory positions that are occupied with the factory default settings Factory If you want to store your own settings in a memory position that is occupied with a User setup you will have to delete this setup first see To delete a memory position on page 91 Use the arrow keys t...

Page 102: ...unction key to toggle between the two settings Note The selection displayed is active 8 3 Displaying instrument and probe information The following information is displayed in the INFORMATION menu Device Information Information about the instrument including The last and the next calibration Option 1 2 options installed Probe Information Information about the probe used Device Diagnostic Service i...

Page 103: ...ow keys to select On and press the OK key The PC interface is set to USB regardless of the set ting made in Serial Interface because the optical in terface is reserved for communication between meters 3 Connect the NBM 550 to the NBM 520 using an optical cable You can then use the NBM 520 as an extended probe handle All the measurement functions of the NBM 550 are available Note The probe must be ...

Page 104: ...orking with the PC software on page 97 2 Start the NBM TS software 3 Activate the connection in the Extras menu via the Connect icon 4 Click on the icon for activation A window in which all the options are listed opens Active options are identified with marked check bo xes 5 Click on the desired option The Option Code field appears 6 Enter the activation code from the Options Passport Document in ...

Page 105: ...the settings you need to make on the NBM 550 It also describes how to update the firmware of the NBM 550 via the PC software You can find detailed information about the PC software itself in the on line help for the PC software 9 1 Using the PC software page 96 9 2 Connecting the NBM 550 page 97 9 3 Working with the PC software page 97 9 4 Updating the firmware page 98 9 5 Performing a reset page ...

Page 106: ...tforward export of measurement data to Microsoft Excel Measurement data management in databases Direct printout of measurement results Screenshots of the displayed windows copy and paste function Bitmap downloads of NBM 550 displays The PC software is essential for performing a firmware update and in order to activate subsequent options Minimum system requirements The following minimum system requ...

Page 107: ...ring the interface on page 90 Connect the NBM 550 to the PC using a USB cable or an optical cable The NBM 550 will be detected as a new device auto matically by the PC 9 3 Working with the PC software The following conditions must be fulfilled before you can work with the PC software The PC is ready to use and the PC software has been installed successfully the NBM 550 is ready to use NBM 550 and ...

Page 108: ...th a simple mouse click to the corresponding website in order to search for a newer version of both the NBM 550 firmware as well as the NBM TS software Always use the most recent NBM TS version to perform a firmware update 2 Establish a connection between the instrument and PC see Working with the PC software on page 97 3 Start the NBM TS software 4 Change to the Extras menu and activate the conne...

Page 109: ...orming a reset Press the 1 function key and the On Off key at the same time The instrument restarts Note A reset does not change any instrument parameters it only restarts the instrument Use the Setup menu to reset the instrument to the factory default settings see Saving and loading instrument settings on page 90 Clear Menu Charge Status ESC OK ...

Page 110: ...9 PC software 100 NBM 550 Narda ...

Page 111: ...ons of the NBM 550 10 1 Measurement menus page 102 10 2 Main menu page 103 10 3 Measurement Settings HF mode page 104 10 4 Measurement Settings LF mode page 106 10 5 Data Logger page 108 10 6 Memory Manager page 110 10 7 Interface page 111 10 8 Information page 112 10 9 Setup page 113 10 10 Clock page 114 ...

Page 112: ...ry with the exception of function key 1 Result Type which is inactive in Monitor display mode Function Meaning Result Type Selects the result type Actual Max Hold Average Max Avg Spatial Average Switches to spatial averaging Hold Freezes the current actual measured value The function key label changes to Release after you press Hold and Hold flashes in the display Press it to unfreeze the measurem...

Page 113: ...ters Information Display information about the instrument and the probe Setup Save and recall instrument settings Clock Set the time and date Function keys Unit 1 1 See Chapter 6 for LF measurements with EHP 50 Select the measured value units W m2 mW cm2 V m A m Display 1 Select the display mode Normal Measured value depending on selected result type XYZ X Y and Z axis results shown separately Mon...

Page 114: ...in Apply Correction Frequency Activate the frequency set under Frequency as a correction frequency On Off Frequency Set the frequency applies to Apply Correction Frequency and Apply Standard Apply Standard Activates the test standard set under Standard On Off The frequency set under Frequency is used as the reference frequency Standard Select a test standard Alarm Function Activate the alarm funct...

Page 115: ...ombi Probe Use Select the field type when using a combination probe E field only H field only E and H field Both field types active E H Field Units select units for simultaneous display of E field and H field only applies in Normal mode Selected Use the units selected using the Unit function key V m and A m Always use V m and A m regardless of the selection made with the Unit function key Results ...

Page 116: ...z 12 Hz 24 Hz 120 Hz 1200 Hz 4800 Hz Frequency mode Type of frequency measurement Wideband Highest value Number of Averages Number of measurements used to take the average 2 4 8 16 32 Magnetic Field Unit Magnetic field units Tesla Gauss Standard Select a measurement standard to be used for the standardized display in Standard display mode Default ICNIRP 1998 occupational Standard WPM Select a stan...

Page 117: ...er Off Set time until automatic power off Off Auto power off disabled 6 min 15 min 30 min 60 min LCD Backlight Set time until backlight switches off Permanent Always on Off Always off 5 s 10 s 30 s 60 s Cal Date Check Check the calibration date when the instrument is switched on On Off Function keys Back Open page 1 of the menu ...

Page 118: ...n1 4 Timer Interval Time between storing consecutive measured values for timer controlled measured value recording 1 s 2 s 3 s 5 s 10 s 20 s 30 s 1 min 2 min 3 min 6 min Store Condition2 optional Start condition for conditional measured value recording Upper THRHLD Recording starts when the threshold defined by Upper Threshold is exceeded Out of gap Recording starts if the value is outside the ran...

Page 119: ... recording of measured values 1 The actual duration is limited by the maximum number of 32000 intervals per data set For dependency of the timer duration on the selected timer interval see table in Setting the recording parameters on page 81 2 Only displayed if EHP 50 display off 3 Up to 32000 events can be recorded 4 After a successful recording the measured values can be viewed with the Data Vie...

Page 120: ...ured value was saved Time Time measured value was saved Type Storage type CON Condition Logging HST History mode MON Monitor mode NOR Normal mode SPA Spatial Averaging TIM Timer Logging XYZ XYZ mode With voice recording comment With EHP 50 LFS Spectrum LF Standard LF3 XYZ LFM Monitor LFT Timer Logging WPV Weighted Peak value WPH Weighted Peak history Free Memory Free memory space Function keys Del...

Page 121: ...th a PC USB Connection via USB cable to the multi function socket Optical Connection via optical duplex cable type RP 02 Controller Function1 Use the NBM 550 to control another NBM 5xx instrument On Off External Trigger Trigger storage externally On Off GPS Position Unit Changes the display of GPS coordinates DMS d dd mm ss s N e g Lat 48 48 10 5 N Lon 9 15 00 0 E MinDec d dd mm mmm e g Lat 48 48 ...

Page 122: ... 2 3 Installed options Probe Information Displays information about the probe that is connected Product Name Probe name Production ID Production number Serial Number Calibration Date Date of last calibration Calibration Due Date Date of next calibration due Shaping Yes or No flat Standard Test standard for shaped probes Field Type E or H Lower Frequency Limit Smallest frequency that can be measure...

Page 123: ...ion key Setup 1 8 Memory positions for storing instrument setups User Indicates that you have stored your own settings at this memory position Factory Indicates that the factory default settings are stored at this memory position not a user setup Function keys Power On Sets the power on behavior Previous The settings in use when the instrument was last switched off are reloaded Default The setting...

Page 124: ...M 550 Narda 10 10 Clock You can set the time and date in the CLOCK menu Function Meaning Time Sets the time Time Format Sets the time format 12 h clock 24 h clock Date Sets the date Date Format Sets the date format mm dd yyyy dd mm yyyy yyyy mm dd ...

Page 125: ...ance This chapter describes how to clean the instrument and how to replace the batteries 11 1 Cleaning the instrument page 116 11 2 Replacing removing the batteries page 117 11 3 Disposal page 119 11 4 Checking instrument functions page 120 ...

Page 126: ...revent streaks and spots wipe off the instrument with a dry cloth while it is still damp NOTICE Damage to the instrument from liquids The instrument may be damaged or destroyed if liquids are allowed to get inside the casing Make sure that no liquid gets inside the instrument NOTICE Solvents Solvents can corrode the surfaces of basic unit probe and AC Adapter Charger You must not use solvents to c...

Page 127: ...tire set Always use identical batteries WARNING Short circuiting the batteries Overheating explosion or ignition of rechargeable batteries or their surroundings Never touch both poles of the batteries simultaneously with a metal object Always close the battery compartment immediately after replacing batteries Never use the NBM 550 with the battery compartment open WARNING Reverse charging of recha...

Page 128: ...nt and disconnect it from all other devices AC Adapter Charger USB 2 Open the battery compartment on the back of the instrument 3 Remove the old batteries and dispose of them according to the waste disposal ordinances applicable in your country 4 Insert the new batteries Make sure you insert them the right way round according to the diagram on the base of the battery compartment 5 Close the batter...

Page 129: ...ent WEEE Do not dispose of this instrument with the normal household waste You should dispose of it in accordance with the waste disposal ordinances in your country Within the European Union all electronic measuring systems purchased from Narda after 13th August 2005 can be returned when they reach the end of their useful life The measuring systems that come under this regulation or the documents ...

Page 130: ...l 3 input channels Probe channel 1 3 4 Bring an appropriate signal source see Appropriate test sources on page 122 near the probe head WARNING Probe is not operating properly Possibly present high radiation values are not recognized Check probes for proper operation with a signal source before using this measuring instrument This is especially important for thermocouples because the sensors can be...

Page 131: ... taken when function test is erroneous Repeat the test move the signal source around the probe head to generate a signal for each of the 3 spatial axes monitor the display while moving the signal source Note Do not use this function test for measurements This test is suitable only for checking probes All 3 channels must respond to the field source It is no fault if some channels display identical ...

Page 132: ...function test Probe Test Source 27 MHz 2244 90 38 Test Source 446 MHz PMR Pocket Radio1 1 PMR Pocket Radios are commonly available in electronics stores Test Source 12 GHz Model 86992 2 Model 8699 only available for North America EF0391 EF0392 EF0691 EF1891 EF6091 EF6092 HF3061 HF0191 EA5091 EB5091 EC5091 ED5091 EF5091 EF5092 ...

Page 133: ...play page 124 12 2 Measurement functions with HF probes page 124 12 3 Result memory page 125 12 4 Interfaces page 125 12 5 Options page 126 12 6 General specifications page 127 12 7 Standards compliance page 128 12 8 AC Adapter Charger page 128 12 9 EHP 50 page 128 12 10 CE Declaration of Conformity page 129 12 11 Declarations of origin page 131 ...

Page 134: ... Maximum Minimum Average Maximum Average Result type XYZ mode Latest values Actual X Actual Y Actual Z for probes with separate axis connections Time averaging Averaging time selectable from 4 s to 30 min 2 s steps Spatial averaging Individual or continuous sampling Multi position spatial averaging Averaging over up to 24 spatially averaged results storage of individual position results and of the...

Page 135: ...duplex 115200 baud no parity 1 start bit 1 stop bit Earphone 3 5 mm jack plug 16 ohms mono only with voice comments option Voice Recorder External triggering for storing results Via multi function plug connector Connecting cable with BNC plug available as optional accessory Triggering by closing a contact External GPS receiver Via multi function plug connector The GPS receiver with connection cabl...

Page 136: ...rding format 8 bit PCM mono saved as WAV file approx 240 kB for a 30 s comment Replay External earphone with output volume control or via the NBM TS PC software GPS position logging Receiver type 12 channel satellite tracking supports DGPS WAAS EGNOS compatible Displayed position data Latitude Lat and longitude Lon selectable units DMS degrees minutes seconds MinDec decimal minutes DegDec decimal ...

Page 137: ...rt 30 C to 70 C Humidity 5 to 95 relative humidity no condensation 29 g m absolute humidity IEC 60721 3 2 class 7K2 Immunity to radiated electromagnetic fields 200 V m 100 kHz to 60 GHz Note The immunity may be less than the specified measurement range of a probe Dimensions H x W x D basic unit Series A B Series C 46 x 98 x 276 mm without probe and GPS receiver 46 x 98 x 282 mm without probe and G...

Page 138: ...restricted to 30 C to 70 C Operating 7K2 IEC 60721 3 for the basic unit extended to 10 C to 50 C Mechanical Storage 1M3 IEC 60721 3 Transport 2M3 IEC 60721 3 Operating 7M3 IEC 60721 3 Ingress Protection IP 42 IEC 60529 ESD and EMC EN 61326 1 2013 Safety EN 61010 1 2010 CE European Union Directives 2014 30 EU and 2014 35 EU Nominal AC line voltage range 100 V to 240 V AC Nominal AC line frequency r...

Page 139: ...12 10 CE Declaration of Conformity Narda NBM 550 129 12 10 CE Declaration of Conformity ...

Page 140: ...12 Specifications 130 NBM 550 Narda ...

Page 141: ...12 11 Declarations of origin Narda NBM 550 131 12 11 Declarations of origin NBM 550 Germany EHP 50 Italy ...

Page 142: ...12 Specifications 132 NBM 550 Narda ...

Page 143: ...550 133 13 Ordering information This chapter contains the information needed for ordering the NBM 550 together with its probes and accessories 13 1 NBM 550 page 134 13 2 Probes page 134 13 3 Accessories page 135 ...

Page 144: ... NBM 550 GPS Mounting Set Earphone 3 5 mm Plug Option Key GPS Voice Condit 2401 40 Probe EF 0391 E Field for NBM 100 kHz 3 GHz 2402 01B Probe EF 1891 E Field for NBM 3 MHz 18 GHz 2402 02B Probe EF 5091 E Field for NBM 300 MHz 50 GHz Thermo 2402 03B Probe EF 6092 E Field for NBM 100 MHz 60 GHz 2402 17B Probe HF 3061 H Field for NBM 300 kHz 30 MHz 2402 05B Probe HF 0191 H Field for NBM 27 MHz 1 GHz ...

Page 145: ...7 MHz 2244 90 38 Tripod Non Conductive 1 65 m with Carrying Bag 2244 90 31 Tripod Extension 0 50 m Non Conductive for 2244 90 31 2244 90 45 Handle Non Conductive 0 42 m 2250 92 02 Carrying Strap Hardcase for SRM NBM 500 3001 90 04 Cable Coaxial Multi pin BNC for NBM 550 Ext Trigger 2 m 2400 90 04 Cable FO Duplex 1000 μm RP 02 2 m 2260 91 02 Cable FO Duplex 1000 μm RP 02 20 m 2260 91 03 Cable FO Du...

Page 146: ...13 Ordering information 136 NBM 550 Narda ...

Page 147: ...Narda NBM 550 137 14 Glossary This chapter explains some important terms that are used in this operating manual ...

Page 148: ...opean Geostationary Navigation Overlay Service European system comparable with DGPS for improving the position accuracy of GPS from 10 to 20 meters to 1 to 3 meters It also warns users when the positioning systems are transmitting incorrect data or if the integrity of the GPS data is restricted for some other reason EGNOS is fully compatible with the American WAAS system EMC Electromagnetic compat...

Page 149: ...hape of the earth to an accuracy of 2 meters using satellites and electronic measuring systems RMS Root mean square This term describes an average mean obtained by taking the square root of the average of the squares of the measured values this method is used when measuring high frequency electromagnetic field strengths The averaging corresponds to a linear average of power density values RSS Root...

Page 150: ...nnected devices and their properties are detected automatically WAAS Wide Area Augmentation System WAAS is part of the SBAS Satellite Based Augmentation System for improving the existing US GPS WAAS signals are transmitted by separate satellites on the same frequencies as GPS and serve to improve the relatively inaccurate GPS position information WAV The WAV file format is a container format for d...

Page 151: ...ield type and units 40 Connecting and setting up EHP 50 26 Connecting the probe 24 Continuous spatial measurement 51 Contrast 37 Controller operation 93 Correction frequency measuring with 62 D Data list see Data Viewer Data Logger 108 Data recording see Data Logger Data Viewer 85 Date and time see Clock Declaration of origin 131 DGPS 138 Discrete spatial measurement 50 Display mode History 52 Mon...

Page 152: ...4 Measured values Freezing 47 Storing 47 Measurement menus 102 Measurement Settings 104 Measurements Conditional recording 82 Recording by timer control 80 Measuring discrete values 50 Measuring values continuously 51 Memory Manager 85 110 Monitor mode 56 Monitor EHP 50 74 N NAD83 139 Normal mode 46 O Operating concept 32 Options activating 94 Ordering information 133 Overview Clock 114 Data Logge...

Page 153: ... menu 113 S field 139 Specifications 123 Spectrum EHP 50 71 SPS 126 139 Standard EHP 50 73 Storing graphical records 54 Switching on 30 T TEM cell 140 Terminology 6 Test sources appropriate 122 Test standard measuring with a 58 Time and date setting 38 Transport and storage 15 Transport case 14 Transport damage 13 Trigger cable 47 Tripod using the 27 U Unpacking 12 Updating the firmware 98 USB 140...

Page 154: ...Index 144 NBM 550 Narda ...

Page 155: ......

Page 156: ...ts com Narda Safety Test Solutions 435 Moreland Road Hauppauge NY 11788 USA Phone 1 631 231 1700 Fax 1 631 231 1711 E mail nardasts L 3com com www narda sts us Narda Safety Test Solutions Srl Via Leonardo da Vinci 21 23 20090 Segrate Milano Italy Phone 39 02 2699871 Fax 39 02 26998700 E mail nardait support L 3com com www narda sts it 2401 98 21 06 15 03 A English ...

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