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NIVELCO MicroTREK HB, Руководство пользователя и программирования, Страница: 65 / 68

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NIVELCO MicroTREK HB Скачать руководство пользователя страница 65

 

htk4014a600p_04

 65/68

 

5.5.

 

T

ROUBLESHOOTING

 

 

Event 

Fault 

Action 

Error messages 

“Tank full” status marker on*, 
reading frozen at max. or min. 
value 

No fault. The level has reached (and possibly risen 
above) the top configured measurement limit and is 
either displaying the maximum (when measuring 
level) or minimum (when measuring distance) output. 

None. Measurements should be normal once the level is in the configured 
measurement range. 

“Tank empty” status marker 
on*, reading frozen at max. or 
min. value 

No fault. The level has entered the gauge’s bottom 
dead zone and can no longer detect a return signal. 
Either the maximum (when measuring distance) or 
minimum (when measuring level) output is displayed. 

None.  
Measurements should be normal once the level is in the configured 
measurement range. 

“Tank full” and “Level lost” 
status marker on*, reading 
frozen at max. or min. value 

No fault. The level has entered the gauge’s top dead 
zone and can no longer detect a return signal. 

Empty the tank below the top measurement range limit and  
check the measurement. 

“Level lost” status marker on*, 
reading is frozen 

The instrument has lost the level signal, has searched 
but not yet found the return pulse. This may occur if 
the pulse has dropped below the threshold. Parasite 
signals from the flange or obstructions in the tank may 
render the gauge unable to identify the correct signal. 

Ensure that tank is emptied below maximum level and check the 
measurement. 
If the signal is not detected then modify the control threshold manually as 
shown in sections 5.1.2.4.2 using the oscilloscope diagram and threshold 
set functions (5.1.2.4). 

“Reference not found” status 
marker on* 

Occurs when there is a problem with the time base on 
the HF board. 

Please contact NIVELCO. 

“Level lost” and 
“Reference not found” status 
markers on*, reading frozen 

The probe has received an electrostatic discharge. 

The gauge will search for the level again and resume readings. If the 
reading remains frozen then the signal converter may have been damaged 
by ESD and may need replacing. Please contact NIVELCO. 

“Flange not found” status 
marker on* 

The signal converter has been incorrectly configured 
to measure with a cable or rod probe when it is 
equipped with a coaxial probe. This may be also due 
to installation on a long nozzle which has the effect 
of attenuating the flange pulse. 

Contact NIVELCO for the corrective procedure. 

 

Содержание MicroTREK HB

Страница 1: ...htk4014a0600p_04 1 68 ...

Страница 2: ...mber BKI ATEX Certificate No BKI16ATEX0018X htk4014m0600p_03 BKI IECEx Certificate No IECEx BKI 09 0001 issue No 1 htk4014a0600p_01 INMETRO Certificate No DNV 14 0169 X Rev 01 htk4014p0600p_03 Ex Russia Certificate No RU C HU MЮ62 B 04400 htk4014o0600p_02 ...

Страница 3: ...htk4014a0600p_04 3 68 GUIDED MICROWAVE LEVEL MEASUREMENT ...

Страница 4: ... with EView2 software 26 5 1 1 EView2 software installation and execution 26 5 1 2 Device programming configuration with EView2 27 5 1 3 Quick Configuration configuration examples 37 5 2 Programming with SAP 300 display unit 44 5 2 1 SAP 300 display unit 44 5 2 2 MicroTREK s behaviour in manual programming mode 45 5 2 3 Manual programming 46 5 3 Programming with HART handheld HHC Communicator 47 5...

Страница 5: ...htk4014a600p_04 5 68 ...

Страница 6: ... sends low power nanosecond wide pulses along an electrically conductive rod cable or coaxial probe with a known propagation speed the speed of light As the pulse reaches the surface of the medium or phase of two liquids altered dielectric constant r a part of it is reflected back to the electronic module The efficiency of the reflected signal depends on the dielectric constant r difference of the...

Страница 7: ...16 5 ft 5 0 5 m 1 64 ft 5 4 20 mA HART Ex ia ATEX IECEx EAC INMETRO 8 Twin rod 11 2 BSP D 6 m 20 ft 6 0 6 m 2 ft 6 Twin rod 11 2 NPT E 0 7 m 2 3 ft 7 4 mm 0 15 inch cable 1 BSP K 0 8 m 2 62 ft 8 4 mm 0 15 inch cable 1 NPT L 0 9 m 3 ft 9 4 mm 0 15 inch cable 11 2 BSP V 4 mm 0 15 inch cable 11 2 NPT W Cable version Cable version 8 mm 0 315 cable 11 2 BSP N 0 m 0 ft 0 0 m 0 ft 0 8 mm 0 315 cable 11 2...

Страница 8: ...isplay 20 C 60 C 4 F 140 F Sealing FPM Viton optional for high temperature version FFKM Perfluoroelastomer Kalrez 6375 EPDM Ingress protection IP67 NEMA 4 4X Power supply 18 35 V DC nominal 24 V DC Ex version 18 28 V protection against surge transients Output data Output signals Analogue 4 20 mA 3 9 20 5 mA passive output error signal 22 mA BUS serial line HART interface terminal resistor max 750 ...

Страница 9: ... 1 8 1 4 Process connection 1 BSP 1 BSP 11 2 BSP 1 BSP 1 NPT 1 NPT 11 2 BSP 1 NPT 11 2 NPT 11 2 BSP 11 2 NPT 11 2 NPT Probe material 1 4401 1 4571 1 4401 1 4571 Nominal diameter of probe 4 mm 0 15 inch 8 mm 0 3 inch 14 mm 0 55 inch 8 mm 0 3 inch 4 mm 0 15 inch 8 mm 0 3 inch 28 mm 1 1 inch Mass 0 12 kg m 0 08 lb ft 0 4 kg m 0 25 lb ft 1 2 kg m 0 8 lb ft 0 4 kg m 0 25 lb ft 0 24 kg m 0 16 lb ft 0 8 ...

Страница 10: ...0 TriClamp DN40 Milch DN50 1 NPT Probe material 1 4401 316 FEP 1 4571 316 PFA 1 4571 316 PP Nominal diameter of the probe 6 mm 0 23 inch 12 mm 0 5 inch 16 mm 0 62 inch Mass 0 16 kg m 0 1 lb ft 0 5 kg m 0 33 lb ft 0 6 kg m 0 4 lb ft Fillet coating material PFA PP Weight dimensions Ø25 x 100 mm Ø1 x 4 inch Weight material 1 4571 316Ti Max medium temperature 150 C 302 F 60 C 140 F MEDIUM TEMPERATURE ...

Страница 11: ...htk4014a600p_04 11 68 DIMENSIONS HTK HTL HTV HTW HTR HTP HTS HTZ HTN HTJ HTT HTU HTD HTE H A H B H C H H HTF HTG HTX HTY HTM HTQ HTI ...

Страница 12: ...ousing 2 Cable gland 3 High temp connection 4 Mono cable probe 5 Weight 6 Twin cable probe 7 Twin cable separator 8 Twin rod separator 9 Twin rod probe 10 Mono rod probe 11 Grounding screw 12 Process connection 13 Coaxial probe ...

Страница 13: ...0 H Ui 30 V Ii 140 mA Pi 1 W Ci 10 nF Li 10 H Ui 30 V Ii 100 mA Pi 0 75 W For dust protection by enclosure Ex tD protection modes Type Metal housing HB 5Ex HT 5Ex High temperature version with metal housing HP 5Ex HH 5Ex Ex marking ATEX II 1 2 D Ex ta tb IIIC T85 C T110 C Da Db II 1 2 D Ex ta tb IIIC T85 C T180 C Da Db Ex power supply Intrinsically safety data Ui 12 5 V DC 30 V DC 3 1 2 IECEx Appr...

Страница 14: ...sing without SAP display HT 6 8Ex High temperature version with metal housing with SAP display HP 6 8Ex High temperature version with metal housing without SAP display HH 6 8Ex Ex marking EAC 0Ex ia IIB T6 T3 Ga X 0Ex ia IIC T6 T3 Ga X 0Ex ia IIB T6 T3 Ga X 0Ex ia IIC T6 T3 Ga X Ex ia IIIC T85 C T110 C Da X Ex ia IIIC T85 C T180 C Da X Ex power supply Intrinsically safety data Ci 10 nF Li 10 H Ui ...

Страница 15: ... C 356 F Maximum permissible surface temperature at the process connection 70 C 158 F 90 C 194 F 100 C 212 F 175 C 347 F 75 C 167 F 90 C 194 F 100 C 212 F 175 C 347 F Maximum permissible ambient temperature 60 C 140 F Temperature class T6 T5 T4 T3 T85 C T100 C T110 C T180 C Temperature limit data for IECEx and INMETRO approvals Temperature data Explosive gas atmosphere Explosive dust atmosphere Al...

Страница 16: ...t which requires the device is protected against any possible sources of spark or ignition resulted by impact or friction effects If the device is equipped with a coated sensor then it should only be operated in a circuit with Ex ia IIB protection mode The size of the status window of devices with Ex ia IIC T6 T3 Ga protection level exceeds the limit therefore the device is to be protected against...

Страница 17: ...empt should be made to lift the instrument by its probe Caution The probe is a critical gauge component Do not damage Handle with care Avoiding blows avoid hard blows jolts impacts etc Caution fragile electronics Avoid bending single rod and coaxial probes Support the probe to avoid bending Avoid cable kinks and fraying Do not coil the cable with less than 400 mm 16 inch in diameter Cable kinks or...

Страница 18: ...onical etc Before installing it please remember to Disconnect the power supply the gauge may be installed when the tank contains the medium Threaded process connections Nozzle height Nozzles penetrating into tank The simplest and most economic way is to mount the MicroTREK 2 wire directly on the tank with the 1 1 BSP or 1 1 NPT threaded connection Do not fit a nozzle longer than its diameter espec...

Страница 19: ...m the electromagnetic EM fields generated by both instruments may cause measurement errors Coaxial probes the outer shell of the probe contains the EM field no minimum distance required Caution Do not put the nozzle close to the entry pipe Pouring the medium directly onto the probe will give false readings Install deflector plate if impossible to distance gauge from entry pipe Tanks with floating ...

Страница 20: ...or probe end other types Avoid mounting near objects discontinuities inside the tank that influence the probe s EM electromagnetic field Install the gauge far from protruding objects such as heating tubes sudden changes in tank cross section tank wall reinforcements and beams weld lines and dip stick pipes etc No electromagnetic field outside the reference chamber When measuring liquids the use of...

Страница 21: ...rom fraying out 3 Insert cable back into counterweight and tighten it with screws 4 Change configuration parameters with respect to the new probe length with the reference point is the top edge of the weight 4 2 2 Specific installation instructions gauge solid applications False readings Conical silo nozzles false readings and traction on the cable probes Do not let the probe touch the side of the...

Страница 22: ... single cable probes 4 3 WIRING Wiring in non Ex environment 1 2 3 4 5 6 1 2 3 4 5 6 HTK 402 4M 200 00 4 20 mA I I mV Test 10 mV 1 mA 1 Detach the cover of the unit 2 Guide the cable into the housing through the cable gland 3 Remove the insulation from the wire in 4 mm 0 16 inch length and cut away the free part of the shielding 4 Connect the wires of the current loop to terminals 2 and 3 any pola...

Страница 23: ...ote E S D cannot be solved by MicroTREK 2 wire E S D protection It is the customer s responsibility to avoid E S D by grounding the tank medium and probe installation DANGER OF INJURY 1 The probe may receive an electrostatic discharge during operation ground the probe by pushing it against the wall of the tank with an adequately isolated tool before touching it to avoid any potential risks electri...

Страница 24: ...erminals Line B minimum supply voltage for voltage drop caused by a 250 Ω loop resistance Example for calculating the power supply The voltage drop is tested at 22 mA U power minimum 22 22 mA x load impedance Uinput minimum 22 U power minimum 22 22 mA x 250 Ω 10 V 5 5 V 10 V 15 5 V In order to cover the whole current range the voltage drop must also be tested at 4 mA By analogy the following appli...

Страница 25: ...he HART adapter should be connected to the intrinsically safe input of the Ex repeater Units with plastic coating should only be used in IIB gas class hazardous area 4 3 1 BUS HART communication MicroTREK has two output options Current out and HART Passive HART protocol Ex ia current out and HART Intrinsically safe passive HART protocol Both versions compatible with HART protocol and can be operat...

Страница 26: ...mmunicator Separately available Automatic device detection upon power on See chapter 5 3 Programming with HART HHC Communicator 5 PROGRAMMING MicroTREK can be programmed in three basic ways Programming with EView2 software Programming with SAP 300 display unit Programming with HART Handheld HHC Communicator For operating instruction see the User manual of the HHC 5 1 PROGRAMMING WITH EVIEW2 SOFTWA...

Страница 27: ...nge Description Tank height P05 0 60 000 mm 2 362 inch The level measurement calculation is based on the height of the tank and the relevant current output level measurements and for the relevant current output It is defined as the distance between the surface of the lower flange and the reference point at the bottom of the tank The output unit is to be determined at the Length unit P01 menu item ...

Страница 28: ...dow Measurement configuration tab Damping time parameter 5 s Probe length P07 Minimum 100 mm 3 94 inch Maximum 24 000 mm 945 inch Set probe length 100 mm 3 94 inch This value should be modified when the probe replaced or shortened cable probes The unit of measurement at the output is to be set by the Length one P01 In case of a special installation the length of the Probe may be selected longer th...

Страница 29: ...tional Unit parameter Unit name conversion factor can be set and the user defined unit will be used as the distance unit The unit selected here is also valid for the following functions if Level or Distance mode is selected in the Current generator mode P11 parameter Tank height P05 Dead zone P06 Probe length P07 Assignment of 4 mA P16 Assignment of 20 mA P17 Detection delay P08 Or the unit in the...

Страница 30: ...um 0 0 Maximum 100 000 Reference for the conversion factor is the millimetre always enter conversion value compared to it At a conversion factor of 10 the new unit is equivalent to 10 mm 0 4 inch At a conversion factor of 0 1 the new unit is equivalent to 0 1 mm 0 004 inch Set value DEVICE SETTINGS window Application tab Optional Units Conversion factor parameter 1 0 Current output Parameter path ...

Страница 31: ...e upper limit of the analogue measuring range Assignment of 20 mA The value of this parameter must always be Lower or equal to the value selected under Tank height P05 or the maximum volume table VMT value Higher than the value selected under Assignment of 4 mA P16 otherwise an error message will appear during parameter check Set value DEVICE SETTINGS window Outputs tab Current output Assignment o...

Страница 32: ...network Standard hardware platform for HART is the current loop with superposed FSK signals For a multidrop application the current output is set to OFF and consequently to a constant 4 mA With a multidrop bus up to 16 pcs of HART devices can be operated together Parameter path DEVICE SETTINGS Identification tab or DEVICE SETTINGS Advanced mode Device Identification tab Polling Address HART short ...

Страница 33: ... down menu for this type of device because this function is regulated by the Current generator mode parameter The VM chart is activated if this parameter Current generator mode is provided as Volume or Ullage Volume The other difference is that there is no VMT tab in the programming window Advanced mode only a Linearization curve tab in Basic mode In case if the required modifications completed in...

Страница 34: ...actions the Oscilloscope diagram window is opening The diagram shows the reflection curve measured by the device To refurbish the graph and to read the data please select Refresh button in the bottom row or hit F4 with the cursor selects the window Following a successful read out a curve similar to the one shown below will appear see figure 1 In case if any level signals are detected then this wil...

Страница 35: ...low figure marked in red Activating this function the cursor switches to a little cross hair Following this the following measurement data of a particular position which is specified by the cursor s position on the curve appears The magnitude of the amplitude the distance of the particular position Please note that Cursor On function does not provide accurate value only calculates the value of the...

Страница 36: ...e of the oscilloscope diagram marked in blue in the previous figure to the left This activates the Threshold value setting field in which the threshold values can be provided To validate the new set up select the Save button or hit enter with the cursor in the setting field Upon this the software downloads the new threshold value to the device and triggers a new reflection curve readout if the Aut...

Страница 37: ...tput VMT Linearization curve set 2 1 7 0 Volume table For volume measurements Example procedures for each set of functions are given on the following pages Each procedure is described by a series of steps in tabular form and is according to the EView2 Configuration parameter list Please refer to section 5 3 Programming with HART handheld HHC communicator for the equivalent parameters available on ...

Страница 38: ... is factory configured by the manufacturer upon the order code Why the height of the tank is to be changed Setting the Tank height to L2 avoids having a non measurable zone underneath the probe where the measurement on the display freezes Set the Tank height to L2 to avoid the device crashes in a non measurable zone underneath the probe When setting up a measurement scale as explained on the follo...

Страница 39: ...alue set 1 Open the DEVICE SETTINGS window of the device in EView2 The device settings are read and displayed 2 Select the Measurement configuration tab Configuration menu displayed 3 Click on the data setting field for Tang height This field currently displays 10000 mm 33 ft 4 Provide the new value 5 Press the Send button in the bottom right corner the MicroTREK to accept the new value 6 Press th...

Страница 40: ...ram What is the difference between these functions EView2 Dead zone P06 HART Fct 2 1 1 4 Dead zone EView2 Detection delay P08 HART Fct 2 1 5 3 Detection delay The detection delay function masks all signals i e none are detected by the gauge up to a defined distance from the flange facing The detection delay zone size is never greater than the dead zone size The EView2 device status menu will displ...

Страница 41: ...thin the Current output section This field currently displays Distance 4 Use the mouse to scroll down to the data set field Click on the new value This field now displays Level 5 Select the Error indication drop down list Hold last measured value message is displayed in this field 6 Use mouse to scroll down data set field Click on the new value This field now displays 22 mA 7 Select the Assignment...

Страница 42: ...n tab and chose the Calculation system Metric EU Imperial US Optional Unit 3 Select Length Unit in the Application tab m or ft 4 Go to Volume Unit to select volume units m or ft 5 Select Measurement configuration tab 6 Go to user function Tank height to enter tank height value click on field and type in value 6 00 m 20 ft 7 Go to user function Probe length to enter probe length value 5 80 m 19 ft ...

Страница 43: ...ng the probes The size of the dead zone depends on the installation and on the probe type Supplementary procedure for setting the 4 20 mA current to output volume readings using EView2 Step Action Data entered value selected 1 Go to Outputs tab to select Volume measurement function in Current generator mode Volume 2 Go to user Error indication function to set the error status to the optimal mode H...

Страница 44: ... 300 display unit Display 64 x 128 Dot matrix LCD glyphs units and bargraph Ambient temperature 20 C 60 C 4 F 140 F Housing material PBT fiberglass plastic DuPont SAP 300 is an universal plug in LCD display and programming module which is compatible with other NIVELCO devices if the device software supports SAP 300 module Warning The display of the SAP 300 is based on LCD technology do not expose ...

Страница 45: ...rned off after 120 sec Press E button to enter the menu Use and buttons to navigate in the menu Enter the selected menu point with E button Exit to the previous menu with button Buttons are working only in the presence of the SAP 300 module When leaving the MicroTREK in programming menu after 30 minutes the instrument automatically returns to measuring mode If SAP 300 is removed the instrument ins...

Страница 46: ...st Navigation is possible as described in the menu lists Accept changes with E button cancel changes and exit with button Numerical field Serves for editing a numeric value Editing is helped by a cursor inverted character Change the value of the selected digit with buttons there is no under and overflow between the characters Selecting a digit can be done using the button Accept changes with E but...

Страница 47: ...icator Communicator layout 1 Two pin jack for loop connectors 2 LCD 3 Function keys F1 F4 4 Action keys On off UP Arrow n a LEFT Arrow DOWN Arrow RIGHT Arrow Other functions LEFT Arrow Previous menu key RIGHT Arrow Select key Wiring standard non Ex Caution Refer to the HHC manual for wiring instructions when the operation is planned in explosive environment ...

Страница 48: ...Online 3 Frequency Device 4 Utility 2 Online 1 Process Var 2 Config Test 3 Access Rights 4 Watch status 5 HART Variables SAVE F1 F2 F3 F4 F1 F2 F3 F4 Main menu Online menu 3 Process Var 1 Measurements 2 Input Outputs 4 Measurements 1 Lvl 878 00 mm 2 Dist 121 00 mm SAVE HOME HELP SAVE HOME F1 F2 F3 F4 F1 F2 F3 F4 Measurement input output functions menu Measurement display function ...

Страница 49: ...2 1 1 0 BASIS PARAMETER 2 1 1 1 TANK HEIGHT Enter probe length to 60 000 mm 2362 Tank height The tank height is defined as the distance between the bottom of the tank and the lower flange surface As per order 2 1 1 2 PROBE LENGTH Enter 0 mm to tank height but 24 000 mm 1063 This value has to be equal to the exact length of the probe The only situation when this value has to be changed is if the pr...

Страница 50: ...t name User has to enter the unit name before using it in the menu LENGTH UNIT UNIT 2 1 2 1 3 2 UNIT FACTOR Enter values between 0 0 to 100 000 Optional unit factor User has to enter the Unit Factor before using it in the menu LENGTH UNIT With a factor 1 0 the unit is equivalent to one millimetre With a factor 1000 0 the unit is equivalent to one meter 1 0 2 1 2 2 0 TÉRFOGAT 2 1 2 2 1 VOLUME UNIT ...

Страница 51: ...ter value between 0 to Scale I max Input the lower range value corresponding to 4 mA depending of the parameter 2 1 3 1 chosen As per order 2 1 3 5 SCALE I max 20 mA Enter value between Scale I min to tank height Input the upper range value corresponding to 20 mA depending of the parameter 2 1 3 1 chosen As per order 2 1 4 0 USER DATA 2 1 4 1 TAG 00000 01 Tag number of devices 2 1 4 2 SERIAL NUMBE...

Страница 52: ...ves in terms of gain amplification factor changing by the electronic converter 500 mV G3 at 1 m 3 3 ft 2 1 5 2 DISTANCE INPUT Enter a value from Fct 2 1 1 4 Dead zone to fct 2 1 1 2 Probe length This function forces MicroTREK 2 wire to search for the medium surface in a zone other than the actual measuring zone If there is no level signal sensed you can enter an estimated value 2 1 5 3 DETECTION D...

Страница 53: ... the settings in the table The units of length and volume used in Fct s 1 2 4 and 1 2 5 shall also apply here 0 i e no volume table 2 1 7 3 DELETE TABLE This function deletes the strapping table 2 2 0 TESTS 2 2 1 TEST OUTPUT Select 4 mA 8 mA 12 mA 20 mA This function allows the current output to be tested The output can be set to one of the listed values Using a reference ammeter the calibration o...

Страница 54: ...d device revision Read only menu 1 0 5 4 SOFTWARE REV Software revision Read only menu 1 0 5 5 HARDWARE REV Hardware revision Read only menu 1 0 5 6 DEVICE ID Read only menu The device ID is also the serial number of the device 5 7 MESSAGE 32 bytes of ASCII characters 5 8 DESCRIPTOR 16 bytes of ASCII characters 5 9 DATE Month Day Year xx xx xx 5 10 NUM RESP PREAM Number of preamble in the response...

Страница 55: ...le configurations the instrument is capable of What happens when the tank is full or empty What is the level Threshold and how to modify it and How to perform a measurement when multiple mediums in the tank The measurement scale five possible configurations for analogue current output with Level LEVEL EView2 Current generator mode Level E F G D H C B A Display frozen in top dead zone 20mA 20mA 20m...

Страница 56: ...7 tank height dead zone 3 The current output range is greater than the measuring range Scale min 4 mA P16 0 0 Scale max 20 mA P17 tank height dead zone 4 The current output range is greater than the measuring range Scale min 4 mA P16 tank height probe length H Scale max 20 mA P17 tank height 5 The current output range is greater than the measuring range Scale min 4 mA P16 0 0 Scale max 20 mA P17 t...

Страница 57: ...ssumes the tank is full and displays the maximum level value The gauge searches for a reflection along the entire length of the probe Zone 2 Full zone and dead zone Marker Tank full is displayed in this zone If the gauge loses the signal in this zone it reacts as in zone 1 the tank is assumed to be full The gauge searches for a reflection along the length of the probe Zone 3 Central measurement zo...

Страница 58: ...or the largest signal that is over a set voltage amplitude called the threshold and identifies this as the medium being measured In order for the signal is applicable by the gauge the microprocessor will amplify the signal by increasing gain Once the signal is within a set working range the gauge follows this signal The gauge registers any changes of the signal returned to the converter and transl...

Страница 59: ...This screenshot taken of the EView2 oscilloscope function while measuring while a typical single medium measurement The function analyses the following data 1 Initial pulse 2 Flange reflection except coaxial probe 3 Non medium reflection e g parasite agitator 4 Medium level reflection 5 Level threshold with two metre steps Set in 5 1 2 4 2 function 6 Offset the distance travelled by the signal bet...

Страница 60: ...ference signals so that only the reflections from the medium surface level signal are shown The factory setting of the level threshold is suitable for standard applications The threshold has to be adjusted in case of very low dielectric constants r multiple interference reflections or unfavourable installation conditions The illustrations below show interference signals when the oscilloscope funct...

Страница 61: ...t too low i e it is below the amplitude of some of the interference signals the device will identify and indicate one of these interference signals as a level reflection even if the tank is empty Precise setting of the level threshold is especially important when the dielectric constant r is low In order to perform the setting level amplitude of the reflection must be known A level of 500 mm 20 is...

Страница 62: ...f the level reflection decreases gain will increase to compensate for the loss in signal amplitude Thus the proportionality of gain and threshold levels remain unchanged At gain 3 the level signal for both figures The reflected useful signal level has dropped weakens smaller amplitude as the distance between the level and the flange increases The interference signals are now below the level thresh...

Страница 63: ...ress enter and press and select save 1100 mV 6 Refresh the oscilloscope diagram F4 key 7 If the value is still too low try to reduce threshold again in small steps If this does not resolve the problem contact the NIVELCO Service Centre Note the threshold drops every 2 m 6 5 ft Solid application notes Most solid applications except powder or flakes with high dielectric constants r such as coal powd...

Страница 64: ...r of approximately 100 mm 3 93 inch when measuring top medium with a dielectric constant of r 2 4 The mode 2 liquids 1 level permits level to be measured even when more than 2 type of liquids are present in the tank The first return signal is identified as level and the second is ignored This mode may be used with all probe types Example application 1 level measurement of oil 1 type of liquid in t...

Страница 65: ... The instrument has lost the level signal has searched but not yet found the return pulse This may occur if the pulse has dropped below the threshold Parasite signals from the flange or obstructions in the tank may render the gauge unable to identify the correct signal Ensure that tank is emptied below maximum level and check the measurement If the signal is not detected then modify the control th...

Страница 66: ...t level value The MicroTREK 2 wire measures a non valid reflection Check the tank for obstructions and verify that the probe is clean In the case the indicated level is close to the nozzle increase the detection delay and the dead zone with the same ratio or increase the threshold level if the full measurement range is essential In any case use the EView2 oscilloscope function to visualise and to ...

Страница 67: ...If the current value drops to a value between 4 and 20 mA and goes immediately back to 22 mA contact your NIVELCO Service Centre The value at the current output does not identical with the value at the display EView2 or HART communicator The current output settings are incorrect Check the current loop and the connections Configure the output as described in User s and Programming Manual of the Mic...

Страница 68: ...htk4014a600p_04 68 68 htk4014a0600p_04 February 2020 NIVELCO reserves the right to change technical data without notice ...

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