Non-Contact DC tester

[753MTE]

Has anyone come across a non-contact tester for DC up to 250vdc?

 

[GoldDigger]

Has anyone come across a non-contact tester for DC up to 250vdc?

You can easily have a non-contact current sensor for DC, but there is no practical way to sense actual voltage that way that will not be vulnerable to zero drift and false readings. (I suppose you could dangle a static-charged ball from a string, but it would not be practical.)

 

[SG-1]

Do you mean something like this ?
They have another one that is more sensitive, down to one gauss.

http://www.mitchellinstrument.com/e...detection-pens/mag-probe-magnetic-tester.html

 

[GoldDigger]

Do you mean something like this ?
They have another one that is more sensitive, down to one gauss.

http://www.mitchellinstrument.com/e...detection-pens/mag-probe-magnetic-tester.html

The gauss is a measure of magnetic field. That is just fine for detecting current, regardless of the voltage or frequency, but will do nothing to detect an energized wire which is not carrying current.

 

[SG-1]

The gauss is a measure of magnetic field. That is just fine for detecting current, regardless of the voltage or frequency, but will do nothing to detect an energized wire which is not carrying current.

The Mag-Probe primary purpose is to determine if relay coils are energized.
This is the only non-contact DC tester that I know of.

 

[gar]

130501-2256 EDT

With a 9 v battery, an MPF103 (FET), some resistors and a diode for reverse protection on the gate I can sense fields from a 20 VDC or less source. Also great for static charge sensing on a rubbed glass or plastic rod. For high fields an LED is a useful indicator.

.

 

[broadgage]

I do not believe that a useful non contact DC voltage detector can be made.
Although ways exist of detecting a DC electrostatic field this would not reliably determine if a conductor was energised or not.
Electric fields from static/friction would be far greater and give rise to so many false readings as to render such a device useless.

 

[GoldDigger]

The Mag-Probe primary purpose is to determine if relay coils are energized.
This is the only non-contact DC tester that I know of.

Would you consider a clamp-on ammeter to be a non-contact tester? They are available for DC too.

 

[SG-1]

Good point, I have a Fluke 90i610s & 337. Wonderful use of the hall effect.

I would really like to have the non-contact voltmeter that uses the laser beam.

 

[Besoeker]

Would you consider a clamp-on ammeter to be a non-contact tester? They are available for DC too.

I regularly use a Hall-effect clamp on for current but I think the OP is asking about voltage.