Digital Volt Meter

vtmaps · January 2012

I decided to buy a second digital volt meter, and was happily surprised to find something different at Radio Shack.

My other dvm, and most dvms that I have seen have ranges of 2 volts, 20 volts, 200 volts, etc. This means that on a 24 volt system I must use the 200 volt range with resolution of 0.1 volt. The Radio Shack dvm has ranges of 4 volts, 40 volts, etc, which means I can read 24 volts on the 40 volt range with two decimal precision :-)
--vtMaps

niel · January 2012

Re: Digital Volt Meter

that sounds interesting. do you have the model number or link? if you bought it how does it seem to compare and does it seem to be accurate.

Redd · January 2012

Re: Digital Volt Meter

vtmaps wrote: »

I can read 24 volts on the 40 volt range with two decimal precision :-)
--vtMaps

Don't let the digits fool you. On a lot of the inexpensive meters, there's often only 1% accuracy, so 13.8 volts can be off by a full tenth of a volt up or down. Then there is noise in the circuitry, and the rightmost digit can be wrong by a count of 2-4 in either direction. So a true "13.85" might really show as 13.99 or 13.71, you can really only use the two or three leftmost digits with any confidence, the rightmost digit on any scale or setting needs to be viewed with some skepticism unless the meter has been calibrated and has known high accuracy. Not a huge difference, but 2/10th's of a volt can be a 20% difference in battery condition.

--Redd

niel · January 2012

Re: Digital Volt Meter

vtmaps,
is this the meter you are talking about?
http://www.radioshack.com/product/index.jsp?productId=4439164
if so that seems to be a nice clamp meter. does it still afford the ability to take measurements with wires as i doubt some of those things are done through the clamp? edit to add i read the manual and it does have leads too.

the left hand range increase to 4 is a nice thing to have as it allows you to keep the same accuracies that you had when reading the smaller voltages without the need to change the voltage range upwards and lose a decimal place and accuracy.

btw, be sure your meter won't read up to 29.99v in the 20 range setting as that is really an indicator of the left hand significant digit point and not of the successive digits afterward. my 20v scale will read voltages up to 29.99v. that clamp meter should allow readings to 49.99v before needing to upgrade the range scale.

give your feedback on your new meter as this may be a good alternative to the one bb has been recommending to everybody and at the same costs.

vtmaps · January 2012

Re: Digital Volt Meter

Sorry to keep you all waiting... I was looking for my paper manual so that I could tell you more about it. I haven't found it, but it is available online. It was $25 in the store where I bought it. Today, it seems to be $35 on RadioShack's website. The accuracy is plus or minus 4 in the last digit. That's why I am so happy to have a 40 volt range... I would rather see 25.46 volts on a 40 volt scale than 25.5 on a 200 volt scale.
The model is: http://www.radioshack.com/product/index.jsp?productId=2103176

niel wrote:

btw, be sure your meter won't read up to 29.99v in the 20 range setting as that is really an indicator of the left hand significant digit point and not of the successive digits afterward. my 20v scale will read voltages up to 29.99v.

neil, I didn't realize that about 20 volt range meters. I bought my new meter because my old one was getting a bit flaky (too many years bouncing around in a toolbox in my truck). I've since thrown it out so I can't check to see if it will read 24 v on the 20 v range.
As far as offering feedback on the meter, I haven't owned it long enough to have an opinion of it.
--vtMaps

Digital Volt Meter

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