TB 9-4931-290-50
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 parenthesis.
Manufacturer and model
Common name
Minimum use specifications
(part number)
AUDIO ANALYZER
Sensitivity: 0.25% harmonic
Boonton, Model 1121 (1121)
content
AUTOTRANSFORMER
Range: 105 to 125 V ac
General Radio, Type W10MT3AS3
(7910809) or Ridge, Model 9020A
Accuracy: 1%
(9020A), or Ridge, Model 9020F
(9020F)
Range: 99.84 mV to 150 V ac
Hewlett-Packard, Model 3458A
(3458A)
Accuracy: 0.025% (.05%)
Dc Range: 973 mV to 100 V
Accuracy: 0.025%
usage accessories, issued as indicated in paragraph 4 above, and are not listed in the
calibration procedure. The following peculiar accessory is also required for this calibration:
decade resistor, Winslow, Model 336 (7907234) or Claristat, Model 240C (240C).
6. Preliminary Instructions
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 result of each test and, whenever the test
requirement is not met, take corrective action before continuing with the calibration.
Adjustments required to calibrate the TI are included in this procedure. Additional
maintenance information is contained in the manufacturer's manual for this TI.
d. Unless otherwise specified, all controls and control settings refer to the TI.
7. Equipment Setup
b. Connect TI to autotransformer.
