TB 9-6625-172-24
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. Where the four-to-one ratio
cannot be met, the actual accuracy of the equipment selected is shown in parentheses.
Table 2. Minimum Specifications of Equipment Required.
Minimum use
Manufacturer and model
Common name
specifications
(part number)
CALIBRATOR
Range:
9 mA ac to 10 A ac
Fluke, Model 5720A (5720A) (p/o MIS-
35947); w/ amplifier, Fluke 5725A/AR
Accuracy: ac mA; 1.25%
(5725A/AR)
ac A; 0.15%
1 to 1100 Ω
Range:
IET Labs, HARS-LX-9-0.001
Accuracy: 0.475%
(HARS-LX-9-0.001)
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 this
calibration procedure.
CALIBRATION PROCESS
6. Preliminary Instructions
a. The instructions outlined in paragraphs 6 and 7 are preparatory to the calibration
process. Personnel should become familiar with the entire bulletin before beginning the
calibration.
b. Items of equipment and accessories used in this procedure are referenced within the
text by common name as listed in table 2 and 3.
c. Unless otherwise specified, verify the result of each test and, whenever the test
requirement is not met, take corrective action before continuing with the calibration.
d. Unless otherwise specified, all controls and control settings refer to the TI.
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.
a. Check TI battery and replace if necessary.
b. Construct a 3-turn, 14-gauge film-coated copper wire coil 6 inches in diameter.