4.3.8 ARC Calibration
ARC calibration is part of the calibration routine but it is not performed on the Sentry Plus
instruments. ARC Calibration is set at the factory. To by-pass these two steps:
Press [F1] = UP to go to Cal Step 15: 'AC ARC 15mA (7mA)'. BY-PASS
Press [F1] = UP to go to Cal Step 16: 'DC ARC 5mA (5mA)'. BY-PASS
4.3.9 IR Resistor Calibration (IRR)
Connect the resistance load (per Table 4-2) between the Sentry Plus instrument's OUTPUT
terminal and RTN/LOW terminal.
Press [F1] = UP to go to
Press [STOP] to return instrument to steady state.
Press [START] to get range1 value.
Press [F1] = INC or [F2] = DEC until the Splus display reads the same as certified load value.
Press [ENTER] to accept reading.
Sentry Plus reverts to "IRR Range1" display (incorporating the new cal value).
Press [F1] = UP to go to
Press [STOP] to return instrument to steady state.
Press [START] to get range2 value.
Press [F1] = INC or [F2] = DEC until the SPlus display reads the same as certified load value.
Press [ENTER] to accept reading.
Sentry Plus reverts to "IRR Range2" display (incorporating the new cal value).
Press [F1] = UP to go to
Press [STOP] to return instrument to steady state.
Press [START] to get range3 value.
Press [F1] = INC or [F2] = DEC until the SPlus display reads the same as certified load value.
Press [ENTER] to accept reading.
Sentry Plus reverts to "IRR Range3" display (incorporating the new cal value).
Press [F1] = UP to go to
Press [STOP] to return instrument to steady state.
Press [START] to get range4 value.
Press [F1] = INC or [F2] = DEC until the SPlus display reads the same as certified load value.
Press [ENTER] to accept reading.
Sentry Plus reverts to "IRR Range4" display (incorporating the new cal value).
Page 84 of 85
Cal Step 17: 'IRR Range1
Cal Step 18: 'IRR Range2
Cal Step 19: 'IRR Range3
Cal Step 20: 'IRR Range4
(1GΩ)'.
(100MΩ)'.
(10MΩ)'.
(10MΩ)'.
Service & Calibration