Re: [alfa] Multi-Meters

[Jon Pike <jhpike@xxxxxxx>]

> I had a digital meter that could not read the flashing voltage of a 
> directional light. The directional was about .5 seconds on and .5 seconds 
> off. The digital meter could not make heads or tails of the signal. The 
> newer DVMs have a bar graph that may be of some use as well as a digit 
> display.
>
> For automotive work I still keep a Simpson 260 close by my side. Just keep 
> the analog volt meters away from computer circuits, something like not 
> enough ohms per volt.
>
>
> Bill LeClair
DMM's will vary as to how fast they sample the signal, and/or how fast 
they update the display.
Typically, the "better" (i.e. more expensive) ones will do this faster, 
more like in .1 to .01 of a second.
If the display gets updated too fast, you can't read it easily, due to 
the less significant numbers always
spinning in a blur,  so you don't want the display being updated any 
faster than .2 or .3 seconds.

Being that you might have the meter taking it's measurments 100X faster 
than that, the feature mentioned
of a bar graph that gets updated faster is possible, and a nice thing 
for those quick fluctuations.

But a really cheap meter will only sample as slow as the display,  
making a mess out of fast changes.

If you want a half way decent meter,  expect to pay $40-50 or more,  and 
brands like Fluke, B&K and
others are good.. Fluke especially.  For $70-120 they have excellent 
meters that have all the nice features
you'ld want.. auto ranging, decent accuracy, continuity beep, etc.  If 
you are cheap.. try to check the meter
on some varying signal, or put the leads on and off a steady signal,  to 
see what kind of response that budget
one has before buying...

Jon  (who's spent much of his life with a meter in his hand)

77 Spider
Irvine, CA
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