TB 9-4931-217-40
(8) Rotate DET GAIN control fully ccw.
(9) Adjust function/arbitrary generator
for a 200 mV rms output with
frequency at 1 kHz.
(10) Decrease function/arbitrary generator signal output level by 80 dB.
(11) Adjust DET GAIN control for a visible indication on NULL DETECTOR.
DET GAIN control will be less than fully cw.
b. Adjustments. No adjustments can be made.
15. Final Procedure
a. Deenergize and disconnect all equipment.
b. Annotate and affix DA label/form in accordance with TB 750-25.
CALIBRATION PROCESS FOR IMPEDANCE BRIDGE, MODELS 290A AND 290B
16. Preliminary Instructions
a. The instructions outlined in paragraphs 16 and 17 are preparatory to the calibration
process. Personnel should become familiar with the entire bulletin before beginning the
calibration.
b. Items of equipment used in this procedure are referenced within the text by common
name as listed in table 2.
WARNING
HIGH VOLTAGE is used or exposed during the performance of
this calibration.
DEATH ON CONTACT may result if
personnel fail to observe safety precautions.
REDUCE
OUTPUT(S) to minimum after each step within the
performance check where applicable.
NOTE
Do not remove TI protective cover except when necessary for
access to internal test points or adjustments.
Reinstall
protective cover immediately after completion of performance
check or adjustment.
NOTE
Unless otherwise specified, all controls and control settings
refer to the TI.
