TB 9-6625-388-24
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification. This bulletin provides instructions for the calibration
of Resistance Bridge ZM-4/U, ZM-4B/U; Leeds and Northrop Models 5300, 5305, and
5430AM1. The manufacturers' manuals and TM 11-2019 were used as the prime data sources
in compiling these instructions. The equipment being calibrated will be referred to as the TI
(test instrument) throughout this bulletin.
a. Model Variations. Variations among models are described in table 1.
b. Time and Technique. The time required for this calibration is approximately 2
hours, using the dc and low frequency technique.
Table 1. Model Variations
Test instrument position/connections
Models
ZM-4( )/U
5430AM1
5300 and 5305
GA SENS switches
Same as ZM-4
None
RES-VAR-MUR switch
Same as ZM-4
R-MU-VR-M
BA +/- binding post
Same as ZM-4
BA +, 1 -
GA 1 and 2 binding post
Same as ZM-4
GA + and -
BA switch INT-BA-EXT
IN-BA-OUT
BA switch IN-OUT
GA switch RMV-GA-HIL
Same as ZM-4
Same as ZM-4
GR and RH binding post
Same as ZM-4
None
X1 and X2 binding post
Same as ZM-4
X1 and X2
MULTIPLE BY
MULTIPLE 1/1000, 1/100, 1/10,
Same as 5430AM1
same as 5430AM1
1/9, 1/4, 1/1, 10/1, 100/1, M1000
M100, M10
Decade switches 1, 10, 100,
Decade switches 1, 10, 100, 1000,
Same as 5430AM1
1000, 1-9, 1-9, 1-9, (O-INF)
1-9, 1-9, 1-9, (O-INF)
2. Forms, records, and Reports
a. Form, records, and reports required for calibration personnel at all levels are
prescribed by TB 750-25.
b. Adjustments to be reported are designated (R) at the end of the sentence in which they
appear. When adjustments are in tables, the (R) follows the designated adjustment. Report
only those adjustments made and designated with (R).
3. Calibration Description. TI parameters and performance applications which pertain to
this calibration are listed in table 2.
