Boonton Power Sensor - Manual (Page 9)

Power sensors have response variations (with respect to the reference frequency) at
high frequencies. Calibration factors ranging from ± 3 dB are entered into the
instrument memories at the desired frequencies. Generally, calibration factors are
within ±0.5 dB. These calibration factors must be traceable to the National Institute
of Standards Technology (NIST) to be meaningful. This is accomplished by sending
a standard power sensor (Thermocouple type) to NIST or a certified calibration house
and comparing this standard sensor against each production sensor. The predominant
error term is the uncertainty of the reference sensor, which is typically 2% to 6%,
depending on the frequency. Refer to Figure 1-3. Calibration Factor Traceability.
NIST
Golden Gate
Calibration Labs
Standard
Sensors
Scalar
Network Analyzer
Sensor
Calibration Factors &
SWR
Figure 1-3. Calibration Factor Traceability
4 Power Sensor Manual