ETS-Lindgren HI-2790B Calibration Comparison System - Manual (Page 22)

22 Operation www.ets-lindgren.com
Microwave Oven Survey Instrument Daily Ellipticity
Check
4.3.1 Zero the instrument to be checked, making sure the access door is
closed or the RF switch is off. Insert the probe of the instrument to
be measured into the HI-2790B probe holding fixture. Make sure
the probe is properly located against the stop on the holding
fixture. Set the scale of the instrument to that used for compliance
testing (usually the 0-2 mW/cm 2 range).
4.3.2 Turn RF POWER switch on and adjust the RF LEVEL control to
obtain a mid-scale reading (approximately 1 mW/cm 2 ) on the
meter being checked.
4.3.3 Rotate the probe to obtain the minimum reading.
4.3.4 Readjust the RF POWER control so that the meter on the
instrument being checked indicates precisely 1.0 mW/cm 2 .
4.3.5 Rotate the probe to obtain the maximum reading.
4.3.6 If this value is less than 1.10 mW/cm 2 , the calibration status of the
meter is acceptable. If greater than 1.10 mW/cm 2 , it may be
rejected.
4.3.7 Record in a permanent log the daily checks on all instruments,
indicating whether each instrument was accepted or rejected.
Microwave Oven Survey Meter Calibration Comparison,
30-Day Check, Initial Conditions
4.4.1 Meters to be checked must be turned on and allowed to stabilize in
accordance with the manufacturer recommendations.
4.4.2 Select the desired probe range, zero the instrument, making sure
the access door is closed or the RF switch is off, and place the
instrument on top of the HI-2790B system to the left of the door.
4.4.3 Place the probe in the holder as described in step 4.1.1 on
page 19. Close the door.