> BTW, Use extreme caution with their multimeters on AC, especially over
> 120V:
>
> http://www.bnl.gov/userscenter/Immediate/cen_tech.asp

Bob's advice is worth noting in general for multimeters.
Many cheaper multimeters are NOT certified for use on AC mains and
using them for AC mains measurements creates a potentially* life
threatening situation.

Short:

Use a CAT IV rated meter for mains measurement if you want to maximise
your life prospects.

CAT ratings are from     IEC 61010-1 2nd Edition	and UL 61010B-1 (UL 31111-=
1)

Longer:

YMMV - I've used various cheap meters on 230 VAC without incident, BUT
you could try it tomorrow and wonder why you died. I've only ever had
one multimeter die due to flashover - and that was many decades ago,
using an analog meter based instrument on the 1000 VDC range to read
what turned out to be about 1200 VDC !!!!

To be "safe" you'd like to be using [tm] a CAT IV rated meter

Wikipedia - measurement categories -
http://en.wikipedia.org/wiki/Measurement_category

A CAT IV meter used at no more than it's labelled measurement voltage
SHULD be safe on any circuit you can connect it to

A CAT III meter SHOULD be safe on any in building measurement you can
make - including feeds on the internal sides of distribution boards.
As the external and internal sides of distribution boards are
potentially* electrically closer than may sometimes be comfortable, a
CAT IV meter may be good insurance for the excessibely death averse.

A CATII meter would probably not be labelled as such and is really in
the gamble and hope category in worst case AC mains measurement
scenarios.

A CAT 1 meter will not be labelled.

This National Instruments White paper on measurement categories is of
interest. Main value is perhaps noting how high a withstand vo0ltage
is needed to meet the various CAT ratings with certainty !!!

             http://www.ni.com/white-paper/5019/en



          Russell McMahon

* pun noted
--=20
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