Testing Continuity with a Voltmeter

[hypnagogue]

Please excuse my ignorance, but I could use some assistance. I need to get a device that will test if current can pass from an electrode through a connected wire on down to a pin that connects to a computer port. (Sometimes the electrical connection fails because of a poor connection between the wire and the electrode.) I have seen this test done before using a voltmeter (it was actually set to beep when it detected a bad connection), but I'm not familiar with how voltmeters are typically constructed-- i.e. whether the feature used to detect bad connections was a standard voltmeter feature or not. (I have looked into it a bit and I believe the test I am speaking of is called a "continuity test," with the above mentioned beeping feature being a "continuity beeper," but I'm not 100% certain.)

I'm currently looking at a cheap voltmeter that I think may be able to do the trick for me, but I'd just like some input from more knowledgeable folk on whether this device will do what I need it to do. The technical details provided on the website are as follows :

Product Features

* DC current: 200micro/2m/20m/200m/10A AC voltage: 200/750V DC voltage: 200m/2/20/200/1000V Resistance (ohms): 200/2K/20K/200K/2M
* Transistor & diode test
* 3 1/2 digit LCD with a maximum reading of 1999
* Low battery indicator

Can a "continuity test" (if that is the right term) be done using transistor/diode tests? If not, is it safe to assume that the "continuity test" feature is so standard for voltmeters that I should take it as a given that this voltmeter will be able to do it?

 

[chroot]

A "continuity test" is really nothing more than a resistance test with a beep. The beep sounds when the measured resistance is very close to zero. Since the beep is annoying in some situations (while incredibly useful in others), most multi-meters have a special setting to enable it.

It's a pretty safe bet that every digital mutli-meter sold today has a continuity function. If it includes sophisticated features for diodes and transistors, I'd be amazed if it didn't also have a continuity beep feature.

If it lacks a beeper, however, you can always just set it to low-range resistance mode, and look at the display. If it's close to zero, you can even say the word beep!

- Warren

 

[ravenprp]

First of all, there is no need to apologize for asking for assistance or for any lack of knowledge. We all have to start somewhere and it's always better to ask for help than to make assumptions and potentially cause damage or injury.

To answer your question, yes, a continuity test can be done using transistor/diode tests. The transistor/diode test function on a voltmeter is designed to check the continuity of a circuit by sending a small current through it. If there is a break or poor connection in the circuit, the voltmeter will not detect the current and will give a reading of "open circuit." This is essentially the same function as a continuity test.

However, it is always best to double check and make sure that the voltmeter you are considering purchasing explicitly states that it has a continuity test function. Some voltmeters may have the transistor/diode test function but not the continuity test function. It is always better to be sure before making a purchase.

In terms of the specific voltmeter you are looking at, it seems to have all the necessary features for a continuity test. It has a low battery indicator which is important for ensuring accurate readings, and it has a 3 1/2 digit LCD display which is standard for most voltmeters. Just make sure that it explicitly states that it has a continuity test function and you should be good to go.

I hope this helps and good luck with your testing!