Series 90 Calibration; Purpose - Cablescan 90 Series Setup Manual

Page 44 Series 90 Setup Manual

SERIES 90 CALIBRATION

PURPOSE

The Series 90 is manufactured with precision components to eliminate manual adjustments to
maintain system accuracy. Calibration of the Series 90 consists of running diagnostic tests to
verify the tester meets specifications. Measurement accuracy is a function of fixed precision
components on the Scanner Control board. Measurement inaccuracies of the Series 90 are
caused by either a component failure or a component out of specifications.
Each time the Series 90 is powered On, it performs a self-test and verifies the test reference
voltage against an internal precision fixed voltage reference. If the test reference voltage is out
of specifications, a warning message is displayed.
Cablescan recommends periodic testing of the Series 90 test points using the diagnostic tests in
TestDiag. Running the Low Voltage components test selection verifies the operation of all test
points in the system. This test verifies that an open or short displayed during regular operation is
not caused by a faulty test point. The Series 90 must be returned to Cablescan for repair if the
tester fails to pass diagnostics.
Measurement accuracy is verified using several resistance values connected across specific test
points. The resistor values and the test point assignments are provided in the schematic in
Appendix A. These resistors are referenced in the software as the Resistor Bank. A Resistor
Bank can easily be made by soldering the resistors to a spare scanner board mating connector.
The resistors should be one percent and should be tested before each calibration using a
calibrated meter. A calibration board is also available from Cablescan and is shown in Appendix
B. To perform a verification (calibration) test, follow the test procedures below. For the high-
voltage Series 90 testers, run both the low-voltage and high-voltage test procedures.