Nulling an HP 431B Power Meter

Radra,

the "Null" feature is used to remove offsets that may arise in the internal circuitry of the power meter. So if you notice a nonzero indication of the meter with no rf power applied to the sensor, simply press the "Null" bottom to get a zero reading of the meter. Probably you may have to repeat this a number of times. You will need this feature only in the most sensible measure ranges, say 100 microwatts downward.

Regards Ulrich

"Radra" schrieb im Newsbeitrag news: snipped-for-privacy@z14g2000cwz.googlegroups.com...

The carbonbased lifeform Ulrich Bangert inspired sci.electronics.equipment with:

Do not forget to terminate (50Ohm) the sensor first, otherwise the calibration is invalid. It is also advisible to let the 431 warm up first, or you'll be repeating the calibration a couple of times.

Theo