TB 9-6625-2325-24
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification.
This bulletin provides instructions for the
calibration of True RMS Voltmeter, Fluke, Models 8920A and 8921A. 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. Model 8920A has BNC input and model 8921A has double
banana input.
b. Time and Technique. The time required for this calibration is approximately 2
hours, using the dc and low frequency technique.
2. Forms, Records, and Reports
a. Forms, 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 in table 1.
Table 1. Calibration Description
Test
instrument
Performance Specifications
parameters
Ac voltage
Range: 0 to 700 V
Accuracy: % of voltage reading or ( dB)
Range
2 mV
20 mV
200 mV
2V
20 V
200 V
700 V
10
to 20
Hz
5 (0.5)
20
to 50
Hz
3 (0.35) 2 (0.25)
1(0.15)
50
Hz to 200 kHz
2 (0.25) 1 (0.15)
0.5 (0.5)
200
kHz to
1 MHz
3 (0.35) 2 (0.25)
0.7 (0.15)
1
to
2 MHz
4 (0.4)
3 (0.35)
N/A
2
to 10 MHz
N/A
4 (0.4)
3 0(.35)
N/A
10
to 20 MHz
N/A
5 (0.5)
N/A
See footnotes at end of table.
