TB 9-6625-1943-24
Table 2. Minimum Specifications of Equipment Required
Manufacturer and model
Common name
Minimum use specifications
(part number)
CALIBRATOR
Range: 105 to 135 V ac
Fluke, Model 5720A (5720A) (p/o MIS-
Frequency: 57.88 to 420.8 Hz
35947)
Accuracy: 0.025%
SECTION III
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 used in this procedure are referenced within the text by common
name as listed in table 2.
c. Unless otherwise specified, verify the results of each test and, whenever the test
requirement is not met, take corrective action before continuing with the calibration.
Adjustments and additional maintenance information are contained in the manufacturers'
manuals for this TI.
d. Unless otherwise specified, all controls and control settings refer to the TI.
7. Equipment Setup
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. Adjust TI mechanical zero (front panel) until each meter indicates first major
division.
b. If necessary, set TI controls as required.
8. Frequency Accuracy
a. Performance Check
(1) Connect calibrator OUTPUT HI and LO to TI 400 Hz input.
(2) Set calibrator for a 120 V, 400 Hz output.
(3) Adjust calibrator frequency for a 400 Hz indication on TI. Calibrator frequency
indication will be between 0.3996 and 0.4004 kHz.
(4) Set calibrator amplitude to 105 V and repeat (3).
(5) Set calibrator amplitude to 135 V and repeat (3).