TB 9-6625-388-35
SECTION IV
AND GRAY INSTRUMENTS MODEL E 20 LEVEL C
12. Preliminary Instructions
a. The
instructions outlined in
paragraphs 12 and
13 are preparatory to the
calibration
process. Personnel should become familiar with the applicable sections before beginning
b. Items of equipment used in this procedure are referenced within the text by common
name and item identification number as listed in tables 3 and 4. For the identification of
equipment referenced by item numbers prefixed with A, see table 3, and for prefix B, see
13. Equipment Setup
a. Unlock the galvanometer. If galvanometer does not indicate zero, loosen screws on
adjustment knob and turn knob to zero the pointer. Tighten screws on adjustment knob.
b. If necessary, insert three BA-30 batteries in TI.
c. When measuring resistance below 1000 ohms, set BA
switch to INT.
d. When measuring resistance above 1000 ohms, set BA
switch to EXT and
connect
power supply (A2), adjusted to 25 volts as indicated on power supply voltmeter, to BA
terminals on TI.
CAUTION
During this procedure, depress and hold TI GS SENS .01, .1,
and 1 switches only long enough to perform the required checks
or adjustments.
14. Resistance Accuracy
a. Performance Check
(1) Position TI controls as listed in (a) through (e) below:
(a) GA switch to RVM.
(b) RES-VAR-MUR switch to RES.
(c) MULTIPLY BY dial to 1/1000.
(d) Decade dials 1000, 100, 10, and 1 to 1.
(e) BA switch to INT.
12