TB 9-6625-2185-35
IDENTIFICATION AND DESCRIPTION
calibration of Radio Frequency Power Test Set, AN/USM-491, (Boonton, Model 4200 RF
Microwattmeter and Series 4200-6E Sensor). TM 11-6625-3164-14 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 4
hours, using the dc and low frequency and microwave technique.
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).
pertain to this calibration are listed in table 1.
Test instrument
parameters
Performance specifications
Power reference
Range: 1.00 mW at 50 MHz
output1
Accuracy: 1.2%
Range: 9 V to 4.5 V dc
Dc voltage
Accuracy: 0.5% + 1 V
Power measurement
Frequency range: 100 kHz to 18 GHz
Power range: -40 to + 30 dBm
Accuracy:
The total accuracy is the sum of uncertainties noted in sections A, B, C,
and D. These uncertainties may also be added in an RSS fashion which
represents the most probable total uncertainty.
RSS = \/ (A2 + B2 + C2 + D2)
A. Basic Uncertainty (includes all instrumentation, noise, zero and
shaping errors and includes 0.7% power reference setting error).
INPUT
POWER
LEVEL
UNCERTAINTY
> 1 W
1.2% of reading 0.1% full scale
< 1 W
1.5% of reading 1.5% full scale
