Boonton 4500B Peak Power Meter - Manual (Page 73)

Boonton 4500B RF Peak Power Analyzer
Operation 4-1
4. Operation
This section presents the control menus and procedures for operating the Model 4500B in the manual mode. All the display
menus that control the instrument are illustrated and accompanied by instructions for using each menu item.
The operation section of the manual begins with instructions on how to calibrate the sensors that will be used with the
instrument. This calibration is required to begin taking measures using the Peak Power Analyzer.
4.1 Calibration
The Model 4500B features a built-in automatic calibration (AutoCal) process that calibrates the peak power sensors for all
measurement modes. An internal programmable calibrator outputs discrete incremental power levels covering the dynamic
range of the sensor. Zeroing is adjusted for the High and Low video bandwidths where applicable.
Note
You must calibrate the channel 1 sensor using the AutoCal routine whenever the Priority Message field
reads ―CH 1 Needs AutoCal‖; and, similarly, the channel 2 sensor when the message ―CH 2 Needs
AutoCal‖ appears. If a sensor is to be used in both channels, a calibration is required for each. During the
power-on initialization, the instrument checks its calibration files and restores channel and sensor
calibration data previously stored. Measurements using a particular channel and sensor cannot be
performed unless a valid set of calibration data is present.
Before beginning calibration a warm-up period may be required. If the instrument is not connected to main power or the rear
panel power switch is off, a 30 minute warm-up period will be required before the sensors can be calibrated to full accuracy.
The front panel power switch is an On/Standby switch, and the calibrator is always powered. If the sensors have not been
connected and the standby power mode has been active, the sensors should be allowed a 15 minute warm up.
Before initiating AutoCal, clear any pending errors by pressing CLR. To initiate AutoCal, press the CHAN function key,
followed by the Chan 1 > Calibration > AutoCal or Chan 2 > Calibration > AutoCal menu keys. See Figure 4-1b. During
AutoCal, progress is reported on the display status line. If necessary, you can abort AutoCal by pressing the ESC key. This
will restore the calibration status that existed before the AutoCal was started.
Calibration accuracy varies with signal power, as described in Subsection 1.6 Specifications. An analysis of calibration
accuracy is presented in Section 6.0 Application Notes.