TB 9-6625-2115-24
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification.
This bulletin provides instructions for the
calibration of Milliohmmeter, Shallcross Model 673D. The manufacturer's manual
was used as the prime data source in compiling these instructions. The equipment being
calibrated will be referred to as the TI (test instrument) throughout this bulletin.
a. Model Variations. None.
b. Time and Technique. The time required for this calibration is approximately 1
hour, using the dc and low frequency technique.
2. Forms, Records, and Reports. Forms, records and reports required for calibration
personnel at all levels are prescribed by TB 750-25.
3. Calibration Description. TI parameters and performance specifications which
pertain to this calibration are listed in table 1.
Test instrument parameters
Performance specifications
Power requirements
1.5 V dc internal battery
Range: 0 to 5 ohms in 5 steps
Accuracy: 5% FS
EQUIPMENT REQUIREMENTS
4. Equipment Required. Table 2 identifies the specific equipment to be used in the
calibration procedure. This equipment is issued with Secondary Transfer Calibration
Standards Sets, AN/GSM-286, AN/GSM-287 and AN/GSM-705. Alternate items may be
used by the calibrating activity when the equipment listed in table 2 is not available. The
items selected must be verified to perform satisfactorily prior to use and must bear evidence
of current calibration. The equipment must meet or exceed the minimum use specifications
listed in table 2. The accuracies listed in table 2 provide a four-to-one ratio between the
standard and TI.
5. Accessories Required. The accessories required for this calibration are common
usage accessories, issued as indicated in paragraph 4 above, and are not listed in the
calibration procedure. The following peculiar accessories are also required for this
calibration: Lead, 24-in., spade lug terminations (red) (7911292-14) (B1) and Lead, 24-in.,
spade lug terminations (black) (7911292-13) (B2).