plug-in home voltage meter with digital readout?

My wish is to purchase a voltmeter that will plug into a home wall
socket and give me a digital readout on the voltage. I use my
multimeter for that, but I'd like something small and permanent that i
don't have to use matchsticks to keep in the wall socket. i live in
Spain , and use 220V curerent. Does such an apparatus exist? Id so,
what's its name and where can it be found?

thanks, eric

 

There are lots of small digital AC voltage meters that are small and
made for panel mount.

E.G.
http://www.topac.com/DPM_AP160.html

You could mount one of these on a receptacle box cover and replace the
receptacle with it, or mount it in a small box and plug it into the
receptacle.

 

Or... but you need to be a little careful. use your existing Voltmeter,
but make a set of test leads that instead of getting poked into the wall,
terminate in a standard plug. You'll need to be careful that you don't
leave it plugged in when the voltmeter is being used elsewhere.

Col.

 

If I was doing this, and I've been tempted, I'd buy a cheap DVM for
the job, and dedicate it to the task. Take an AC cord, and wire it to
the DVM. Run it off batteries for simplicity.

The real issues would be working things so the plugs don't come out of
the meter, with that live AC. Better to drill into the case, and wire
to the actual circuit board, though then one needs to cover the jacks
so that does not expose the AC voltage. Or buy one of those DVMs
where the leads are permanently attached to the meter, those tend to
be the cheapest anyway, and cut off the probes and splice the AC cord
to them, taking proper precautions. And/or it might make sense to
put a resistor, or a pair of resistors, into the AC plug so current
is limited at the other end. Use a voltage divider there, and simply
use a lower voltage scale on the meter.

The other issue is ensuring the function switch can't accidentally be
changed. Not the smartes thing to leave a switch available when it
can mean applying higher AC voltage to the ohm function. Maybe glue
the switch to that position? Or mount the meter inside a metal box
(useful anyway for ensuring those probe jacks are isolated) so the switch
is not accessible by the average person.

Since one is measuring AC line voltage, one could even get fancy, and
put in a small transformer and make a DC supply so the meter is run off
the line, and there goes the battery.

Michael