Giga-tronics 8650A Series, Operation Manual

Page: 200 / 240

Series 8650A Universal Power Meters
4-2 Manual 31470, Rev. E, April 2001
4.3 Calibrator Verification Procedure
If any of the instrument performance characteristics are not within specifications, refer the problem to
Giga-tronics Customer Service.
4.3.1 Calibrator Output Power Reference Level
This test determines if the Calibrator Output Power Reference Level given in this section is valid for an
ambient temperature range b5° C and +35° C (+41
°
F to +95° F).
The Calibrator Output power reference is factory adjusted to 1 mW
±
0.7%. To achieve this accuracy,
Giga-tronics uses a precision measurement system with accuracy to
±
0.5% (traceable to the NIST -
formerly the NBS), and allows for a transfer error of
±
0.2% for a total of
±
0.7%. If an equivalent
measurement system is used for verification, the power reference oscillator output can be verified to
1 mW
±
1.9% (
±
1.2% accuracy,
±
0.5% verification system error
, ±
0.2% transfer error, for a maximum
error of
±
1.9%). To ensure maximum accuracy in verifying the Calibrator Output power reference, the
following procedure provides step-by-step instructions for using specified test instruments of known
capability. If equivalent test instruments are substituted, refer to the Key Characteristics section in
Table 4-1.
Procedure:
In the following steps, thermistor power measurements will be made using the 432A Power Meter. For
detailed information on using the 432A, please refer to the operating section on the 432A manual.
1. Turn on the 8650A and the associated test equipment.
2. After 15 minutes, turn the 8650A’s power OFF and ON. This establishes the 1mW reference
for the instrument firmware.
3. Connect the Thermistor Mount to the 8650A Calibrator output “N” type connector as show
in Figure 4-1. Allow a 15 minute thermal equilibrium period between the Thermistor and
Calibrator connector to minimize temperature differences.
Figure 4-1: Calibrator Output Test Setup