Tektronix 1503C Скачать руководство пользователя страница 33 | Manualshive

Страница: 33 / 128

Tektronix 1503C Скачать руководство пользователя страница 33

Operating Instructions

1503C MTDR User Manual

1–17

Small impedance changes, like those from a connector, might have reflections from
10 to 100 m . If rho is positive, it indicates an impedance higher than that of the
cable before the reflection. It will show as an upward shift or bump on the waveform.
If rho is negative, it indicates an impedance lower than that of the cable prior to the
reflection. It will show as a downward shift or dip on the waveform.

If the cable has an open or short, all the energy sent out by the 1503C will be
reflected. This is a reflection coefficient of rho = 1, or +1000 m for the open and
–1000 m for the short.

Cable attenuation influences the return loss and reflection coefficient measurements
made with the 1503C. If you desire to measure the return loss of only an impedance
mismatch, the cable attenuation, as measured with an open or short circuit on the
cable, must be subtracted from the directly measured value.

For reflection coefficient, the directly measured value of rho must be divided by the
value measured with an open or short circuit on the cable. These calculations can
be done manually, or the instrument can perform them by proper use of the VERT
SET REF function.

It is is not possible to measure the cable under test with an open or short, sometimes
another cable of similar type is available to use as a reference. Note that cable
attenuation is strongly influenced by signal frequency and, therefore, will be
different from one pulse width to another on the 1503C.

When pushed, the VIEW INPUT button displays the input at the front panel CABLE
connector. When VIEW INPUT is turned off and no other buttons are pushed, the
display will not have a waveform on it (see Figure 1–15). The default condition
when the instrument is powered up is to have VIEW INPUT on.

O

F

F

O

F

F

O

F

F

O

N

ac

0.00 ft

Figure 1–15: Display with VIEW INPUT Turned Off

Effect of Cable

Attenuation on Return

Loss and Reflection

Coefficient Measurements

Using VIEW INPUT

«
...
31
32
33
34
35
...
»

Содержание 1503C

Страница 1: ...User Manual 1503C Metallic Time Domain Reflectometer 070 7323 05 This document applies to firmware version 5 04 and above www tektronix com...

Страница 2: ...and foreign patents issued and pending Information in this publication supercedes that in all previously published material Specifications and price change privileges reserved Tektronix Inc P O Box 50...

Страница 3: ...tions This warranty shall not apply to any defect failure or damage caused by improper use or improper or inadequate maintenance and care Tektronix shall not be obligated to furnish service under this...

Страница 4: ......

Страница 5: ...ng to Use the 1503C 1 4 Display 1 5 Front Panel Controls 1 5 Menu Selections 1 7 Test Preparations 1 10 Cable Test Procedure 1 12 Additional Features Menu Selected 1 24 Operator Tutorial 2 1 What is t...

Страница 6: ...Ring Adapter 3 17 Option 09 Universal Service Ordering Code 3 18 Option 10 Token Ring Interface 3 18 Power Cord Options 3 18 Accessories 3 19 Appendix A Specifications A 1 Electrical Characteristics...

Страница 7: ...usted to One Division in Height 1 16 Figure 1 15 Display with VIEW INPUT Turned Off 1 17 Figure 1 16 Display of a Stored Waveform 1 18 Figure 1 17 Display of a Stored Waveform and Current Waveform 1 1...

Страница 8: ...2 15 Noise Reduced 2 10 Figure 2 16 Noise Reduced to Minimum 2 10 Figure 2 17 Incident and Reflected Pulses with Cursor at 0 00 ft 2 11 Figure 2 18 Incident and Reflected Pulses with Cursor at 10 0 f...

Страница 9: ...System 2 Cable w Revision One Repeater 1 avg 200ft div 2 25dB 3 13 Figure 3 11 System 2 First Tap No Traffic 1 avg 1 ft div 44 5 dB 3 13 Figure 3 12 System 2 Same Tap with 5 Traffic 1 avg 1 ft div 44...

Страница 10: ...00 ft B 8 Figure B 12 Pulse Adjusted to Four Major Divisions in Height B 8 Figure B 13 Aberrations Less Than Four Divisions Out to 30 00 ft B 9 Figure B 14 Pulse Adjusted to Four Major Divisions in He...

Страница 11: ...r an internal lead acid battery that supply a minimum of five hours operating time see the Specifications appendix for specifics Options available for the 1503C are explained in the Options and Access...

Страница 12: ...erformance are in the Performance Checks appendix These checks should satisfy the requirements for most receiving or incoming inspections The 1503C is intended to be operated from a power source that...

Страница 13: ...s greater than the equipment dimensions to allow for cushioning The test strength of the shipping carton should be 275 pounds 102 5 kg Refer to the following table for test strength requirements SHIPP...

Страница 14: ...support 1 800 833 9200 select option 1 Service support 1 800 833 9200 select option 2 Technical support Email support tektronix com 1 800 833 9200 select option 3 1 503 627 2400 6 00 a m 5 00 p m Pac...

Страница 15: ...ductor must be connected to earth ground Before making connections to the input or output terminals of the product ensure that the product is properly grounded The standard power cord 161 0288 00 is r...

Страница 16: ...ppear on the product DANGER indicates an injury hazard immediately accessible as you read the marking WARNING indicates an injury hazard not immediately accessible as you read the marking CAUTION indi...

Страница 17: ...rature is below 35 C or above 65 C the battery pack should be removed and stored separately see 1503C Service Manual for instructions on removing the battery Battery storage temperature should be betw...

Страница 18: ...the care of the battery pack They contain instructions that reflect on your safety and the performance of the instrument The 1503C can be powered by a rechargeable lead gel battery pack that is acces...

Страница 19: ...C within minutes Either switch to AC power or work very fast If the instrument is equipped with a chart recorder using the recorder will further reduce the battery level or the added load might shut d...

Страница 20: ...cover and you are ready to test cables The following pages explain the front panel controls O F F O F F O F F O N 1 avg 0 00 db 2 ns ac 0 00 ft MENU VIEW INPUT VIEW STORE VIEW DIFF STORE POSITION INPU...

Страница 21: ...can be reduced by using noise averaging Averaging settings are between 1 and 128 The time for averaging is directly proportional to the averaging setting chosen A setting of 128 might take the instrum...

Страница 22: ...the left of this control on the LCD 9 n o POSITION This is a continuously rotating control that positions the displayed waveform vertically up or down the LCD 10 n o POSITION This is a continuously ro...

Страница 23: ...er possible c Impedance Values displays impedances of common cables In some cases these values have been rounded off Manufacturer s specifications should be checked for precise values d Finding Unknow...

Страница 24: ...circuits ii Noise Diagnostic measures the internal RMS noise levels of the instrument iii Impedance Diagnostic tests the output impedance circuits in the instrument iv Offset Gain Diagnostic reports...

Страница 25: ...uration of the option port for communicating with devices other than the optional chart recorder and one item test the option port a Option Port Diagnostic creates a repeating pattern of signals at th...

Страница 26: ...ntrast value will remain in effect until the instrument is turned off Test Preparations Vp is the speed of a signal down the cable given as a percentage of the speed of light in free space It is somet...

Страница 27: ...panel 2 Pull POWER on 3 Turn the DIST DIV to an appropriate setting e g if trying to find the Vp of a three foot cable turn the DIST DIV to 1 ft div 4 Turn the n o POSITION control until the distance...

Страница 28: ...ted Pulse Set Correctly Cable Test Procedure Be sure to read the previous paragraphs on Vp 1 Set the 1503C controls POWER On CABLE Cable to BNC IMPEDANCE 50 NOISE FILTER 1 avg DIST DIV see below Vp pe...

Страница 29: ...ncreasing the pulse width will allow the reflected pulse to be more visible when testing long cables AUTO will select the pulse width for you depending on the distance on the right side of the LCD CAB...

Страница 30: ...ion might be required This example uses a longer cable 4 When inspecting a 455 foot cable a setting of 100 ft div allows a relatively fast inspection If needed turn VERT SCALE to increase the gain The...

Страница 31: ...he distance to the fault on the distance window of the LCD Return loss is another was of measuring impedance changes in a cable Mathematically return loss is related to rho by the formula Return Loss...

Страница 32: ...gnal going into that point It is designated by the Greek letter and is written in this manual as Rho The 1503C measures reflection coefficient in millirho thousandths of a rho To measure a reflection...

Страница 33: ...must be subtracted from the directly measured value For reflection coefficient the directly measured value of rho must be divided by the value measured with an open or short circuit on the cable These...

Страница 34: ...re is no waveform in memory a message appears on the LCD informing you of this O F F O N ac 3 00 ft Stored Waveform O N O N Figure 1 17 Display of a Stored Waveform and Current Waveform When pushed on...

Страница 35: ...nfusing NOTE Because the stored waveform is not affected by changes in the instrument controls care should be taken with current waveform settings or the results could be misleading One method to mini...

Страница 36: ...ommon situation is to store the waveform of a suspect cable repair the cable then compare the two waveforms after the repair During repairs the VIEW INPUT VIEW DIFF and VIEW STORE waveforms can be use...

Страница 37: ...one great care should be taken to make sure the vertical and horizontal scales are identical for the two waveforms being compared If either the stored or current waveform is clipped at the top or bott...

Страница 38: ...reference point O F F O F F O F F O N ac 0 00 ft D Figure 1 24 Cursor Moved to End of Three Foot Lead in Cable NOTE Vp changes will affect where the reference is set on the cable Be sure to set the Vp...

Страница 39: ...OISE FILTER fully counterclockwise Set Ref will appear in the noise averaging area of the LCD 2 Adjust the incident pulse to the desired height e g four divisions It might be necessary to adjust n oPO...

Страница 40: ...pulse width remains the same for both the incident and reflective pulses Additional Features Menu Selected The 1503C will capture and store waveforms on an ongoing basis This is useful when the cable...

Страница 41: ...NU repeatedly until the instrument returns to normal operation This feature puts the 1503C in a listening mode by turning off the pulse generator 1 Attach a cable to the 1503C front panel CABLE connec...

Страница 42: ...ay it 1 Attach a cable to the 1503C front panel CABLE connector 2 Push MENU to access the Main Menu 3 Scroll to Setup Menu and push MENU again 4 Scroll to Acquisition Control Menu and push MENU again...

Страница 43: ...more Even though other instruments might show a cable as good the 1503C can show many previously hidden faults You the Operator The 1503C is a highly accurate cable tester It is easy to use and will p...

Страница 44: ...the table on page 1 10 or find the Vp with a sample piece of cable using the procedure on page 1 10 or use the Cable Information Menu If it is impossible to obtain the Vp of the cable the instrument...

Страница 45: ...rises This is the classic signature of an open cable a point of higher impedance 4 Adjust the VERT SCALE control This will increase the height of the pulse For accurate measurements the pulse should...

Страница 46: ...e shorting device e g jumper wire 7 Remove the short With a little practice you will be able to identify many kinds of cable faults The Waveform Up Close It helps to know what makes up a pulse Here is...

Страница 47: ...ntrol so the cursor is at the beginning of the rise of the incident pulse Note the distance window reads approximately 0 40 ft This is the distance from the front panel BNC connector to the pulse gene...

Страница 48: ...ERT SCALE 10 dB DIST DIV 100 ft 25 m Vp appropriate setting for your cable PULSE WIDTH Auto clockwise 2 With these settings we can view the entire cable By placing the cursor at the rise of the reflec...

Страница 49: ...cable it would be very tiring to scroll the entire length from end to end at 1 ft div 5 Turn the n o POSITION control to return the cursor to the rise of the reflected pulse 6 Increase DIST DIV to 10...

Страница 50: ...IDTH to 1000 ns The pulse is now longer than the example cable This would be a good pulse for a very long cable O N ac 456 00 ft O F F O F F O F F Figure 2 13 Pulse Width at 1000 ns Longer than the Ca...

Страница 51: ...MPEDANCE 93 NOISE FILTER 1 avg VERT SCALE 0 00 dB DIST DIV 1 ft 0 25 m Vp 84 PULSE WIDTH 2 ns n o POSITION 50 0 ft 2 Attach the 50 terminator to the end of the test cable using the female to fe male B...

Страница 52: ...e Reduced to Minimum 6 Move the n oPOSITION control and notice how averaging restarts at a low value to allow easy positioning The 50 terminator was used here because it gives a good impedance match B...

Страница 53: ...avg VERT SCALE 0 00 dB default DIST DIV 1 ft div 0 25 m PULSE WIDTH 2 ns no terminator NOTE If the POWER was left on from the previous step return the distance window reading to 0 00 ft with the n o...

Страница 54: ...ac 0 00 ftD Figure 2 19 New Zero Set at End of Test Cable 6 To change the HORZ SET REF position turn the NOISE FILTER back to HORZ SET REF and repeat the above procedure with a new cursor location 7...

Страница 55: ...t in the cable before it gets to that fault Here is how to correct for this loss and be able to make accurate measurements at the far end of the cable 1 Connect the test cable 2 Turn the NOISE FILTER...

Страница 56: ...receding procedure 6 If you wish to totally exit VERT SET REF do the following a Turn NOISE FILTER to VERT SET REF b Turn VERT SCALE for a display reading of 0 00 dB or 500 m c Push STORE d Return the...

Страница 57: ...again O F F O F F O F F O N ac 0 00 ft Figure 2 24 Display with VIEW INPUT Turned On This function can be used to make the display less busy when viewing stored waveforms STORE and VIEW STORE These fu...

Страница 58: ...strument 4 Turn the POWER off for a few seconds then turn it back on Note that the STORE indicator block is ON showing that there is a waveform in memory 5 Short the connector at the far end of the te...

Страница 59: ...IFF This adds a waveform in the lower portion of the display that is the mathematical difference between the stored waveform and the current waveform O N ac 0 00 ft O N O N O N Figure 2 28 Stored Curr...

Страница 60: ...ON control scroll down to Setup Menu 5 Press MENU to accept this selection 6 Scroll down to Acquisition Control Menu 7 Press MENU to accept this selection 8 Scroll down to Max Hold is Off 9 Press MENU...

Страница 61: ...s darkened 15 With a clip lead or other device short the far end of the test cable then remove the short Note that both conditions now appear on the display O N ac 0 00 ft O N Figure 2 30 Short and Op...

Страница 62: ...the line length increases sags during the heat of the day shorting out on a tree limb During the night the cable cools tightens and is no longer shorted on the tree limb 18 To exit Max Hold access th...

Страница 63: ...returns to normal operation 1 Set the 1503C front panel controls to CABLE Attach 10 ft cable IMPEDANCE 93 NOISE FILTER 1 avg VERT SCALE 0 00 dB default DIST DIV 1 ft div 0 25 m Vp 84 PULSE WIDTH 2 ns...

Страница 64: ...Cable with a Captured Single Sweep 13 Remove the short and notice that the waveform does not change 14 Press VIEW INPUT again and a new sweep will be made and displayed showing the change in the cable...

Страница 65: ...ative velocity of propagation Vp The velocity of the cable is expressed in time distance e g feet per nanosecond The velocity of electricity traveling in a vacuum is compared to the velocity of electr...

Страница 66: ...e cross sectional area gauge length and the type of material the conductor is made of usually copper Q11 What factors determine the impedance of a cable A11 Dielectric value of the insulation and geom...

Страница 67: ...system signals flow in all directions and the transceivers attached to the Ethernet receive all transmissions Ethernet cable is typically 50 Ohms with 50 Ohm terminators at each end to prevent signal...

Страница 68: ...ork share resources such as terminals disks printers etc The 1503C with Option 06 allows testing of an Ethernet bus while the network is active This is important because some installations might be in...

Страница 69: ...nter Bridge Fiber Optic Link Host Host PC PC PC Micro Computer Micro Computer Network Figure 3 1 A Typical Ethernet System Before Starting here are some things you should know to make Ethernet tests e...

Страница 70: ...ord is disconnected The first test usually run on an active network is the normal sweep with the 2 ns or 10 ns pulse and the DC 50 W termination is On from the Ethernet Menu This test provides basic T...

Страница 71: ...ed during testing allowing the 1503C to become the 50 load When removing the 1503C or there is a power failure the terminator should be reconnected restoring the normal 50 load for the network The BNC...

Страница 72: ...ISE FILTER 1 avg VERT SCALE see below DIST DIV appropriate setting for cable length PULSE WIDTH 2 ns or 10 ns Vp to cable specifications POWER ON see below CAUTION DO NOT use the Auto pulse width mode...

Страница 73: ...width The following tests are composed of several functions found in the Acquisition Control Menu These combinations are displayed in the Ethernet Menu as a user convenience Most of the tests in the...

Страница 74: ...akes from about one to 20 seconds depending on noise averaging and reduces the traffic displayed on the waveform NOTE Movement of any control that would change or move the waveform will start a new sw...

Страница 75: ...uctions chapter of this manual 50 DC Termination is Off On CAUTION This must be on for use on a working network or reflections will cause collisions on the network This entry is a duplicate of the ent...

Страница 76: ...l operation so any combination can be chosen then activated Waveform Signatures By now you probably have a good idea what traffic looks like on the display and how you can use the NOISE FILTER to redu...

Страница 77: ...F F O N Figure 3 4 System 1 Tap Hidden by Traffic 1 avg 50 ft div 35 dB O N ac 173 36 ft O F F O F F O N Figure 3 5 System 1 Traffic and Tap Nearly Identical 4 avg 50 ft div 35 dB O N ac 173 36 ft O F...

Страница 78: ...ft O F F O F F O N Figure 3 7 System 1 Tap Quite Visible 128 avg 50 ft div 35 dB O N ac 173 36 ft O F F O F F O N Figure 3 8 System 1 No Traffic 1 avg 50 ft div 35 dB O N ac 167 56 ft O F F O F F O F...

Страница 79: ...rier is On the pulses might exceed the collision or traffic thresholds of the repeater causing it to send back jamming packets that are synchronized with the 1503C This creates an unusual waveform tha...

Страница 80: ...Figure 3 13 System 2 Same Tap Increased Averaging 16 avg 1 ft div 44 5 dB O N ac 742 52 ft O F F O F F O F F Figure 3 14 System 2 Farther Out More Gain 128 avg 10 ft div 53 5 dB O N ac 714 12 ft O F...

Страница 81: ...Figure 3 16 System 2 Previous Waveform Expanded 128 avg 20 ft div 54 75 dB O N ac 1116 84 ft O F F O F F O F F Figure 3 17 System 2 Next Group of Taps 128 avg 20 ft div 54 75 dB O N ac 1034 44 ft O F...

Страница 82: ...1 See typical frequency response curve below this table to estimate at other fre quencies Once the termination is turned on it will remain on until specifi cally turned off by the operator at which ti...

Страница 83: ...3 21 Typical Frequency Response Curve with Ethernet Option 06 Option 07 YT 1S Chart Recorder Option 07 instruments come equipped with a splashproof chart printer Refer to the Y 1 YT 1S Chart Recorder...

Страница 84: ...r 1502C instruments Option 10 Token Ring Interface Option 10 instruments come with an adapter that allows you to connect the 1503C to Token Ring networks via the MAU Power Cord Options The following p...

Страница 85: ...H 50 W 3 foot Test Cable w Option 06 only 012 1350 00 H Operator Manual 070 7323 xx H Slide Rule Calculator 003 1419 00 H Accessory Pouch 016 0814 00 H Service Manual 070 7170 xx H Battery 040 1276 00...

Страница 86: ...158 00 H Connector BNC male to Type F female 013 0126 00 H Connector BNC female to GR 017 0063 00 H Connector BNC male to GR 017 0064 00 H Precision 50 Cable S N wB010625 012 1350 00 H Terminator 75 B...

Страница 87: ...10 ns 100 ns 1000 ns 2 ns 20 5 0 VDC 10 for 10 ns 100 ns 1000 ns Internal cable length prevents 2 ns pulse from reaching full unterminated voltage Pulse Shape 1 2 sine Pulse Output Impedance Accuracy...

Страница 88: ...screen Vp Range Resolution Accuracy 0 30 to 0 99 0 01 within 1 Propagation velocity relative to air Custom Option Port Tek chart recorder is designed to operate with the 1503C Produces a high resoluti...

Страница 89: ...0 g 11 ms 1 2 sine wave total of 18 shocks 4 drops each face at 4 inches or 45 degrees with opposite edge as pivot 4 drops each face at 4 inches or 45 degrees with opposite edge as pivot Satisfactory...

Страница 90: ...bpart B Class A Limits Safety Standards U S Nationally Recognized Testing Laboratory Listing UL1244 Standard for electrical and electronic measuring and test equipment Canadian Certification CAN CSA C...

Страница 91: ...ical office home environment Temporary condensation occurs only when the product is out of service Pollution Degree 3 Conductive pollution or dry nonconductive pollution that becomes conductive due to...

Страница 92: ...Appendix A Specifications A 6 1503C MTDR User Manual...

Страница 93: ...foot coaxial cable 012 1351 00 Disconnect any cables from the front panel CABLE connector Connect the instrument to a suitable power source a fully charged battery pack or AC line source If you are us...

Страница 94: ...lar to Figure B 1 O F F O F F O F F O N bat 0 00 ft Figure B 1 Start up Measurement Display 2 Connect the 10 foot cable to the front panel CABLE connector The display should now look like Figure B 2 O...

Страница 95: ...w upper right corner of the LCD should be from 3 50 to 3 70 feet 1 05 to 1 11 m O F F O F F O F F O N bat 3 60 ft Figure B 4 Cursor at End of 10 foot Cable Vp Set to 30 5 Remove the 10 foot cable and...

Страница 96: ...sing the n o POSITION control verify that the entire waveform can be moved to the very top of the display off the graticule area O F F O F F O F F O N bat 50600 00 ft Waveform off display Figure B 6 W...

Страница 97: ...F O F F O F F Figure B 8 Waveform with Gain at 57 dB 2 Press MENU 3 Using the n o POSITION control select Diagnostics Menu 4 Press MENU again 5 Using the n o POSITION control select Service Diagnostic...

Страница 98: ...not look normal If the efficiency is more than 100 the waveforms will appear noisy If the efficiency is below the lower limit the waveform will take longer more pixels to move from the bottom to the t...

Страница 99: ...controls IMPEDANCE 50 NOISE FILTER 1 avg VERT SCALE 0 00 dB PULSE WIDTH 2 ns Vp 99 5 Connect the 50 W precision terminator to the front panel 6 Turn the NOISE FILTER control completely counterclockwis...

Страница 100: ...ivisions high out to 10 feet 3 05 m O F F O F F O F F O N ac 10 00 ft Figure B 11 Waveform Centered Cursor at 10 00 ft 13 Return the cursor to 2 00 ft 0 61 m 14 Turn NOISE FILTER back to VERT SET REF...

Страница 101: ...high out to 30 feet 9 15 m O F F O F F O F F O N ac 30 00 ft Figure B 13 Aberrations Less Than Four Divisions Out to 30 00 ft 23 Return the cursor to 2 00 ft 0 61 m 24 Turn NOISE FILTER back to VERT...

Страница 102: ...N ac 300 00 ft Figure B 15 Aberrations Less Than Four Divisions Out to 300 00 ft 33 Return the cursor to 2 00 ft 0 61 m 34 Turn NOISE FILTER back to VERT SET REF 35 Set the DIST DIV to 500 ft div 10...

Страница 103: ...the failure has been identified and corrected All of the previous checks only test the major functional blocks of the instrument that could prevent you from being able to make measurements It is poss...

Страница 104: ...Appendis B Operator Performance Checks B 12 1503C MTDR User Manual...

Страница 105: ...then back three clicks turn the PULSE WIDTH knob all the way counterclockwise remove any accessories that might be plugged into the Option Port e g chart printer and disconnect any cable that might be...

Страница 106: ...ar zero Ohms Turn instrument off immediately to avoid possible damage to LCD display If error message s appear follow the displayed instructions Using VOM check for near zero Ohms in fuse Is waveform...

Страница 107: ...ecked once each time the TDR gets a waveform If the TDR is being controlled by or through the Option Port device you will probably have to remove that device and make manual measurements until the fai...

Страница 108: ...es that the instrument executes The instrument searches for a point on the leading edge of the pulse that is on the cable inside the instrument about 10 up the pulse This message indicates that the se...

Страница 109: ...tric Constant vs Velocity Factor H Time vs Short Distance in centimeters or inches any dielectric H Time vs Long Distances in meters or feet any dielectric Terms and Symbols RS Source Resistance of a...

Страница 110: ...1 00 1 05 1 10 1 15 1 20 1 25 1 30 1 35 1 40 1 45 1 50 VWSR 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 01 02 03 05 10 2 3 5 7 1 0 2 3 5 7 10 20 50 100 30 SINGLE RESISTIVE DISCONTINUITY ONLY RET...

Страница 111: ...flectometry can be accurately expressed in terms of return loss A narrow impulse will be attenuated by losses in the cable and reflections will be attenuated likewise As with measurements on VSWR ther...

Страница 112: ...reflections may be signi ficantly degraded or attenuated by two way losses of the line 1r 100 1 150 50W 50W 50W 1000 500 300 200 100 70 40 1000 600 400 300 200 100 90 80 70 60 45 40 120 100 90 80 70...

Страница 113: ...cables having a higher impedance than the selected source resistance put the sliding reference level even with the bottom stationary scale markings For cables having a lower impedance than the selecte...

Страница 114: ...iding scale to correspond with the one selected as the reference level on the TDR display The impedance Ohms causing the reflection can then be read from the sliding scale by noting the position on th...

Страница 115: ...cale that corresponds to that number next to the stationary arrow labeled METERS then reading the distance in feet next to the point of the arrow labeled FEET Likewise feet are converted to meters usi...

Страница 116: ...the distance on the INCHES and CENTIMETERS scale If the distance to or between faults is known and you want to find the time or velocity factor set the distance under the appropriate arrow first then...

Страница 117: ...oth ends of the circuit at nearly the same electrical potential In early electrical systems and modern systems that over long distances use the earth and or air as the return path and the term ground...

Страница 118: ...o generate only AC often have a DC component see Insulation A mathematical term that refers to the set of numbers that can be put into a function the set of numbers that comes out of the function is c...

Страница 119: ...ctor instead of being sent to the load The polarity of the reflected pulse will be the opposite of the incident pulse and rho will be 1 If there is no mismatch between the cable and the load almost no...

Страница 120: ...trical energy that is reflected back from points along a cable A conductor s opposition to the flow of DC electrical energy through it All conductors have a certain amount of resistance Resistance is...

Страница 121: ...y worn leaky or missing insulation The change in accuracy of a standard or item of test equipment over an extended period of time Unless otherwise specified the period of time is assumed to be the cal...

Страница 122: ...Glossary Glossary 6 1503C MTDR User Manual...

Страница 123: ...ormance Checks Collision 3 2 Connectors BNC BNC 3 19 BNC to Alligator 3 19 BNC to Banana 3 19 BNC to Binding Post 3 19 BNC to F Type 3 20 BNC to GR 3 20 BNC to Hook Tips 3 19 BNC to N Type 3 19 BNC to...

Страница 124: ...0 L Loss 1 15 M Maintenance C 1 D 1 Max Hold see Maximum Hold 2 18 Maximum Hold 1 24 2 18 Menu 1 7 1 24 2 1 2 18 Cables 1 7 Diagnostics 1 8 Chart Recorder 1 9 Head Alignment 1 9 LCD Chart 1 9 Front Pa...

Страница 125: ...Pulse see Controls 1 6 1 13 1 25 2 1 2 9 2 20 1000ns 2 8 100ns 2 8 10ns 2 8 2ns 2 7 Incident 2 3 2 5 2 11 2 12 Reflected 2 3 2 11 2 12 Pulse Inverter 3 20 Pulse Spec A 1 Q Questions and Answers 2 23 R...

Страница 126: ...tical Set Reference 2 12 Vertical Scale 2 5 2 13 Vertical Scale Spec A 1 Vertical Set Reference 1 23 2 12 Vibration Spec A 3 View Diff see View Difference View Difference 1 18 2 17 View Input 1 17 2 1...

Страница 127: ......

Страница 128: ......

Отзывы:

Нет отзывов