TB 9-6625-1942-24
13. Probe Accuracy
a. Performance Check
NOTE
This paragraph to be performed only on TI models supplied
with high voltage probe.
CAUTION
LOW and GUARD input terminals must be securely connected
to TI chassis to prevent accidental damage to TI.
(1) Set FUNCTION switch to DC and RANGE switch to 10V.
(2) Connect high voltage probe to TI.
(3) Connect high voltage probe tip and ground lead to calibrator.
(4) Set calibrator output for a nominal 1000.0 V dc output.
(5) Adjust calibrator error control for a 1.0000 V indication on TI. If indicated error
is not within 0.25% ( 0.5% for K25-3490A probe), perform b below.
NOTE
Perform (5) through (9) below for K25-3490A probe only.
(6) Set calibrator output for a nominal 1000.0 V ac output at 20 Hz.
(7) Adjust calibrator error control for a 1.0000 V ac indication on TI. Calibrator
error display will indicate 0.5%.
(8) Repeat (7) above at 120 and 400 Hz. Calibrator error display will indicate 0.5%.
b. Adjustments
(1) Adjust calibrator for 1000 V dc output.
(2) Adjust R4 (K24-3490A probe) or R5 (K25-3490A probe) for a 1.0000 V dc
indication on TI (R)).
14. Final Procedure
a. Deenergize and disconnect all equipment and reinstall protective covers on TI.
b. Annotate and affix DA label/form in accordance with TB 750-25.
