Multimeter

Hi I want to buy a new Multimeter and there are a few features that
currently I have no idea what they mean. Obviously I currently have
no
idea for those features but I wondered if somebody can explain to me
what they are/do so maybe in the future I will need them.
1. Conductance
2. Motor Drive Measurement
3. Smoothing
4. Duty Cycle

 

Look at these: http://www.testequipmentdepot.com/fluke/dmm/index.htm

 

Sadly (and surprisingly) none of the four were on the Common DMM
Terminology link from that page.

Conductance is the multiplicative inverse of resistance, G = 1/R, in
units of siemens (sadly, no longer mhos). Not terribly useful most of
the time but easy to derive for a digital meter and makes another
"range" that Marketing can flog. G not C since C was already taken.

Motor drive may go along with smoothing. It's a feature mostly useful
for voltage/frequency measurements of large electric motors (duh ;-)
because they tend to be electrically very noisy critters and "normal"
meters may give false readings.

Duty cycle is the fraction of the period of a when a signal is
(selectable) high or low, usually expressed as a percentage. A
symmetrical square wave has a 50% duty cycle. Useful in checking an
PWM circuit, for example.