Biddle TDR900_UG 电路图.pdf

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1、Time Domain Reflectometer Megger TDR900 USERS MANUAL MeterCenter 2046 W. Peninsula Circel - Chandler, AZ 85248 USA Telephone: (480) 659-8351 Toll Free (800) 230-6008 Fax: (480) 659-8361 Email: SalesMeterC Websites: www. MeterC www.BiddleM Copyright 2003 Fine Instruments Corp. All right reserved. Spe

2、cifications subject to change without notice. Litho in Korea. RadioFans.CN 收音机爱 好者资料库 Basic Specifications Maximum Range: Depends upon the V.O.P of the cables under test. 12,000 ft (3.7 km) V.O.P99.9 % 9,800 ft (3.0 km) V.O.P80.0 % 8,000 ft (2.4 km) V.O.P66.0 % 6,200 ft (1.9 km) V.O.P50.0 % Range Se

3、lection: Automatic range control Resolution: 20 inches (50 cm) Accuracy: 2 % of reading + 20 inches (50 cm) 300 ft (100 m) This accuracy is effective for Coaxial Cables up to 8,000 ft, Telephony Cables up to 6,000 ft, and Structured Wiring up to 3,000 ft. Output Impedance: 25, 50, 75, 100, 125 or 15

4、0 ohms Impedance Selection: Automatic output impedance control Velocity Factor: Adjustable from 1.0 % to 99.9 % Tone Generator: Oscillating 810 - 1100 Hz (5 Vp-p unloaded) Cable Library : 39 standard cable types Memory Location : 20 for custom cable types Connector: BNC Input Protection: 250 V RMS L

5、ine Voltage Detection : 6.5 V SOURCES LIKE SMALL HAND-HELD RADIO TRANSCEIVERS, FIXED STATION RADIO AND TELEVISION TRANSMITTERS, VEHICLE RADIO TRANSMITTERS AND CELLULAR PHONES GENERATE ELECTROMAGNETIC RADIATION THAT MAY INDUCE VOLTAGES IN THE TEST LEADS OF THE MULTIMETER. IN SUCH CASES THE ACCURACY O

6、F THE MULTIMETER CANNOT BE GUARANTEED DUE TO PHYSICAL REASONS. W A R N I N G ! Warning The product should not be connected to any energized circuits. Connection to mains supply voltages will damage the Meter and could be hazardous to the user. The product contains parts that can be damaged by static

7、 discharge. Discharge the cable to be tested before connecting the product to the cable. Read “Safety Information” before using this Meter. 1 RadioFans.CN 收音机爱 好者资料库 1. Safety Information3 2. The TDR Cable Length Meter4 3. Controls, Indicators, and Buttons Overview5 4. Meter Operation8 4.1 Principle

8、s of operation8 4.2 How to connect a cable to the Meter8 4.3 How to set the cable type9 4.3.1 Selecting a library cable type9 4.3.2 Cable library for 39 standard cable types10 4.3.3 Testing cables not included in library12 4.4 How to determine unknown V.O.P settings14 4.4.1 Expanding cable library f

9、or custom cable types using nonvolatile memory15 4.5 How to measure cable length19 4.6 How to check networks (Thin Ethernet)19 5. Changing the measurement scale between English and Metric20 6. Measurement accuracy21 7. Theoretical and actual V.O.P22 8. Special features23 8.1 Low battery indication23

10、 8.2 Overrange indication23 8.3 Enable or disable the auto-power-off mode24 8.4 Tone Generator mode25 8.5 Line Voltage Detection mode25 9. Maintenance26 10. Specifications27 Repair and Warranty CONTENTS Safety Warnings This Meter complies with the safety requirements of IEC 1010-1 : 2001. It is desi

11、gned for use on de-energized circuits only, however this Meter is protected against telephone networking voltages (EN 60950 : 1999 Sec. 2.3). Connection to any mains supply voltages may result in damage to the Meter and/or a hazard to the user. Hence the user must assume responsibility for ensuring

12、his or her own safety. International Symbols used on the Meter Caution! Refer to the explanation in this manual. Double insulation or Reinforced insulation Battery Meter complies with current EU Directives. International Standards Safety: IEC 1010-1 : 2001 EMC: EN 61326 : 1997+A1: 1998 1. Safety Inf

13、ormation EMC StandardCategory of Pass ESDIEC 1000-4-2A EMIEC 1000-4-3A BurstIEC 1000-4-4A SurgeIEC 1000-4-5A Conducted RFIEC 1000-4-6A 23 RadioFans.CN 收音机爱 好者资料库 The Meter is a handheld and battery operated instrument capable of measuring cable lengths and finding distance to an open or a short usin

14、g TDR(Time Domain Reflectometry) techniques, given access to one end only. The Meter can be used for any cable consisting of at least two insulated metallic elements, one of which may be the sheath or shield of the cable. The Meter has automatic internal matching networks to allow testing of 25 , 50

15、 , 75 , 100 , 125 , or 150 cables, which correspond to power, telephony, CATV, and LAN, etc. cables. The Meter can be closely matched to the cable under test using the menu selection keys. The V.O.P(Velocity of Propagation) value can be similarly adjusted to match the cable under test; thus ensuring

16、 an accurate distance measurement. The Meter incorporates an oscillating tone generator, that is detectable with a standard tone probe (not supplied) available in the marketplaces, for use in the tracing and identification of pairs within a cable . The Meter displays “ ” message and stops operation

17、if line voltage of the cable under test exceeds 6.5 V when the Meter is turned on. The BNC terminal is protected up to 250 V RMS in order to prevent it from being demaged by its misconnection to live circuits of networking. You can store up to 20 cable test results for custom cable types in internal

18、 nonvolatile memory and the stored cable library provides quick and easy access to 39 standard cable types, which enables accurate measurement without the necessity of entering V.O.P (Velocity of Propagation). The on-site measurement scale changing feature enables the Meter to be globally used for b

19、oth Metric measurement and English measurement without changing the measurement scale at factory. The Meter comes with an Alligator Clip adaptor, a users manual and a soft carrying case. 2. The TDR Cable Length Meter Although this manual describes the operation of the Meter for both Metric measureme

20、nt and English measurement, all illustrations and examples assume use of the Meter for English measurement. ( 1 ) ( 3 ) ( 4 ) ( 7 ) ( 5 ) ( 6 ) ( 2 ) 3. Controls, Indicators, and Buttons Overview 54 (3) MENU (on screen) SELECTION BUTTONS Each setting of the Meter to a measurement function may activa

21、te one or more menu selection button settings on the LCD. Press the corresponding menu selection button to select the desired measurement. Setup Mode Use the menu selection buttons in order to edit desired setup values as follows : (4) POWER ON/OFF BUTTON Press the POWER button for more than 1 secon

22、d to turn the Meter on. Auto-Power-Off This Meter is completely turned off after 30 minutes of no activities. Press the POWERbutton to turn the Meter on again. This feature can be disabled (refer to Section 8.). (5) BACKLIGHT ON/OFF BUTTON or EXIT BUTTON Press this button for more than 1 second to t

23、urn the backlight on and press this button again for more than 1 second to turn it off. Press this button momentarily to always return to the initial display when the meter is in either SELECT mode or Memory mode. And also press the button momentarily to exit the Tone Generator mode. (6) MEMORY BUTT

24、ON or TONE BUTTON Press this button momentarily to activate the memory mode. The display shows three menu selections : STORE, RECALL andCLEAR. Press this button for more than 1 second to activate the Tone Generator mode. (Press the EXIT button to exit the Tone Generator mode.) (7) TEST BUTTON Press

25、this button momentarily to measure length, distance to an open or a short, or V.O.P of cable under test. (1) DISPLAY Extra-large backlit (ICON type 7 segment) LCD. When the Meter is turned on, all display segments and symbols appear briefly (during 1.5 seconds) for a selftest and then the Meter defa

26、ults the following initial display. Initial Display When shipped out of factory The Meter defaults V.O.P of 66.0 % and English scale. When turned on after having been used in the field The Meter defaults the V.O.P (e.g. 68.0 %) having been used just before it was turned off. (2) BNC A shielded conne

27、ctor for either coaxial cable or Alligator Clip adaptor (a standard accessory). Fig. 1 Fig. 2 Button Function Press to step to next digit in setting value. Press to increase setting value. Press to decrease setting value. Press to move to next Setup. Press to save all settings and exit Setup Mode wh

28、en setting is ended. 76 4.1 Principles of operation The Meter works by measuring the time taken for a signal to travel to the far end of the cable (or to an intermediate fault) and to return. The velocity at which the signal is transmitted (Velocity of Propagation, that is, V.O.P) will depend upon t

29、he characteristics of the cable to be tested. The length is computed from the following formula : travel time X (9.84 X 108) X V.O.P (English measurement) travel time X (3 X 108) X V.O.P (Metric measurement) The V.O.P is specified for standard cable types in this manual. However, do not rely solely

30、on the specified V.O.P because variations of up to 20 % can occur between batches of cable. Therefore, if accuracy is critical to your situation, you must determine the actual V.O.P of each cable. Verify the length measurement by measuring a sample cable (longer than 30 ft, or 10 m) of the same cabl

31、e type you will be testing. 4.2 How to connect a cable to the Meter Ensure that no power supply or equipment is connected to the cable to be tested. Ensure that the far end of the cable to be tested is either open or shorted (not fitted with a terminator). Connect the Meter to one end of the cable t

32、o be tested. The cable connection to the Meter is via a BNC connector located at the top of the Meter. For unterminated cables use the Alligator Clip adaptor as follows. Coaxial cable: Connect the red clip to the center wire and the black clip to the shield. Shielded cable: Connect the red clip to a

33、 wire adjacent to the shield of the cable and the black clip to the shield. Unshielded twisted pair cable: Separate one pair out and connect the two clips to the two wires of a pair. Unshielded multi-core cable: Connect the two clips to any two wires. 4.3 How to set the cable type The Meter needs to

34、 be set for the cable type to be tested before being used to take measurements. If the cable type is listed in the library, setting up is simply a matter of selecting the appropriate cable type from the library. 4.3.1 Selecting a library cable type The library cable type you will select determines t

35、he information about V.O.P and the abbreviated trade name of the cable to be tested. 1. Turn the Meter on. 2. The Meter will display the previously selected cable setting (see Fig. 1 and Fig. 2) with its V.O.P. 3.Press the SELECT button then the Meter will display both the LIBRARY symbol (blinking)

36、and the V.O.P symbol. 4. Press the OK button to set the Meter to the LIBRARY mode. The Meter will display the information of the LIBRARY No. 1, when the “ ” will be blinking. 4. Meter Operation Fig. 3 98 “ blinking ” 5.Scroll through the library using the ,and buttons to find the required cable type

37、. The types are displayed in the Library Number order. The 39 standard cable types are listed in Section 4.3.2 and Section 4.3.3 will explain you how to make the library of 20 customer cable types using the memory mode. 6.Press the OK button to set the Meter to the required cable type. The center li

38、ne segments of 6 digits in the lower display will be blinking until the TEST button will be depressed. 7.Connect the cable to be tested to BNC connector of the Meter. 8.Press the TEST button to take the required measurements. The displayed V.O.P will be remained on the LCD even after the TEST button

39、 was depressed in order to inform the user of the V.O.P of the cable to be tested. When the Meter will be continuously set to the just same cable type as the preceding cable type, the Meter will show the preceding display until the TEST button will be newly depressed. When the Meter is turned off it

40、 automatically stores the last setting and will display this setting when powered up. Fig. 4 1110 “ blinking ” 4.3.2 Cable library for 39 standard cable types 4.3.3 Testing cables not included in library If the cable type to be tested is not in the library, it can still be tested if the V.O.P is kno

41、wn. If the V.O.P is unknown, refer to Section 4.4. 1 . Turn the Meter on. 2 . The Meter will display the previously selected cable setting see Initial Display of Section 3.(1) with its V.O.P. 3 . Press the SELECT button then the Meter will display both the LIBRARY symbol (blinking) and the V.O.P sym

42、bol (see Fig. 3). 4 . Press the button then the LIBRARY symbol will stop blinking and the V.O.P symbol will be blinking. 5 . Press the OK button to set the Meter to the V.O.P adjusting mode, when the LIBRARY symbol will disappear, the V.O.P symbol will stop blinking, and the “ ” segments will start

43、to blink. The Meter can enter into the Calibrate Cable function to determine the V.O.P for a known length of cable by pressing any button out of and buttons when the Meter is in the V.O.P adjusting mode. Then, the will appear replacing the and “ 30.00 ” will be blinking to alert the user that a samp

44、le cable longer than 30 ft (10 m) is necessary. Fig. 5 6.Press the OK button again then the default V.O.P value of 66.0 % will start to blink. 7.Scroll through the V.O.P value between 1.0 % and 99.9 % by using the , and buttons to find the required V.O.P value. 8 .Press the OK button to set the Mete

45、r to the required V.O.P value. 9 .Connect the cable to be tested to BNC connector of the Meter. 1 0 . Press the TEST button to take the required measurements. For example, the Meter can have the following display. Fig. 6 Fig. 7 1312 “ blinking ” “ blinking ” 4.4 How to determine unknown V.O.P settin

46、gs The Calibrate Cable function allows you to determine the V.O.P for a known length of cable and save it for additional measurements of unknown lengths of the same type of cable. V.O.P settings are stored in nonvolatile memory. To calibrate a cable manually, perform the following steps : 1 .Take a

47、sample of the cable at least 30 ft (10 m) in length to obtain the specified accuracy (longer lengths improve accuracy). 2 .Measure its length by direct measurement. 3 .Repeat the step 1 to step 5 of Section 4.3.3 then press the button or the button in order to set the Meter to the Calibrate Cable fu

48、nction, when the will appear replacing the and “30.00” will be blinking to let you remind that the length of a sample cable should be at least 30 ft (10 m). 4 .Connect the sample cable to the Meter and set the actual length of the sample cable using the , and buttons. NOTE Lengths measurements are o

49、nly as accurate as the V.O.P setting for the cable to be measured. V.O.P values can vary substantially between cable manufacturers as well as between cable lots. Measure and record the V.O.P of a sample length of cable for each cable manufacturer, then mark the V.O.P on each cable drum before installation. Fig. 8 5.Press the OK button. 6.Press the TEST button to read the V.O.P of the sample cable, when the center line segment of 6 digits will blink waiting for the next measurement. For example, 7.Connect the cable to be tested to the Meter. 8.Press the TEST button to tak