3M™ Advanced Systems Tester 900AST Series
Use the [RFL] key to find the distance to a resistance fault between two conductors or a conductor and ground.
This key is used for editing only.
Use the [TDR] key to activate the Time
Domain Reflectometer.
Use the [Auto] key to activate automatic TDR trace analysis.
CAUTION
The 900AST tester is a tool for troubleshooting wiring problems. It is not designed for troubleshooting electronic circuits or instrumentation. The ohms, soak, contact resistance, special resistance and RFL functions generate a current limited (< 1 mA) 80V stimulus.
TDR and Auto TDR functions generate
Circuit testing should be performed by personnel trained in electrical safety practices and in accordance with applicable safety standards.
Connecting to Coaxial Wires for Testing
Ensure that electrical power has been removed and components disconnected from the wiring to be tested before beginning wiring tests.
Note: For best operation, use the special coaxial TDR test leads supplied with your 900AST tester to perform coaxial wire TDR measurements.
The TDR test cable has a standard male BNC connector on the end. Plug the opposite end of the TDR test leads plug into the Red/Black and/or Blue/ Yellow test jacks on the 900AST tester (one or more cables may be used depending on the desired TDR mode.)
Connect the end of the TDR test cable to the coaxial wire to be tested. Use a BNC adapter (if needed) to connect to the coaxial circuit under test.
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