Wideband power sensor (wps) measurements, Description, Zeroing sensor – Bird Technologies VPM3 User Manual
Page 56: Description zeroing sensor
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Wideband Power Sensor (WPS) Measurements
Note:
WPS Firmware V1.45 or latter is required to operate on the
VPM3.
Description
The Bird Wideband Power Sensor (WPS) is a Thruline sensor that can measure
average, peak, or burst power, VSWR, crest factor, and Complementary Cumu-
lative Distribution Function (CCDF).
Note:
Firmware upgrades extending the WPS’s capabilities may be
periodically released. For the latest firmware upgrade, contact Bird
Customer Service at (866) 695-4569 or visit the Bird website at
Zeroing Sensor
Over time, the sensor’s “zero value” (reading with no applied RF power) can
drift, making all readings inaccurate by this value. For example, if the zero value
is –0.02
W, measuring a 50
W signal will give a reading of 49.98
W, a 0.04%
error. Measuring a 1
W signal will give a reading of 0.98
W, a 2% error. If the
drift would be a significant error, rezero the sensor:
1.
Ensure the sensor has reached a stable operating temperature.
2.
Ensure no RF power is applied to the sensor.
3.
Press “Zero” to begin Calibration. See “Zeroing a Sensor” on page 32.