TB 9-6625-388-35
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Decade resistors..................................................
Ratio resistors.....................................................
Murray loop accuracy .........................................
Final procedure...................................................
CALIBRATION PROCESS FOR ZM-4/U, ZM-
4A/U, ZM-4B/U, 1-49, 1-49A, AND 1-49B
AND GRAY INSTRUMENTS MODEL 3207
(LEVEL C)
Preliminary instructions ....................................
Equipment setup ................................................
Resistance accuracy............................................
Murray loop accuracy .........................................
Final procedure...................................................
SECTION I
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification. This bulletin provides instructions for levels A and
C calibration of Resistance Bridge ZM-4/U, ZM-4A/U, ZM-4B/U, I-49, I-49A, and I-49B;
Industrial Instruments Model RN-1; Leeds and Northrop Models 5300, 5305, and
5430AM1; and Gray Instruments Models E3108 and E3207.
The manufacturer's
instruction manuals and TM 11-2019 were used as prime data sources in compiling these
instructions. The equipment being calibrated will be referred to as the "TI" (test
instrument) throughout this bulletin.
b. Time and Technique. The time required for this calibration is approximately 2
hours, using the dc and low frequency technique.
2. Calibration Data Card, DA Form 2416
prescribed by TM 38-750. DA Form 2416 must be annotated in accordance with TM 38-750
for each calibration performed.
b. Adjustments to be reported on DA Form 2416 are designated (R) at the end of the
sentence in which they appear. When adjustments are in tables, the (R) will follow the
designated adjustment. Report only those adjustments made and designated with (R).
3. Calibration Description. TI parameters and performance specifications which
pertain to this calibration are listed in table 2.
2
