Multimeter help needed

[Diver233]

There are meters with an 'alert' function, that makes a beeping noise and/ or flashes up 'LEAD' if you select a voltage range with red lead still in the current socket. Of course, if you also leave the meter on a current range and try to measure the voltage, that's no help.

But what are these people doing? I swap the leads on mine from current to voltage many, many times a day, every day, and haven't made this mistake for a decade or more. You need to drill into them the significance of checking the connections and settings for every setup bar none.

It's a good job they aren't trying to use a vintage valve tester. You can destroy a valuable AVO VCM instantly (beyond economic repair as the special panel meters haven't been made for years) just by turning one of its dials one click too far. FWIW the girls who used to help out on a Saturday never seemed to have any difficulty using them accurately.

Was thinking about your answer and yes you have summed it up completely.
“You haven’t made this mistake for a decade or more”.
Trouble is these are mainly brand new engineers on short courses and they probably won’t make the mistake again for a decade or more, how do I stop them doing their first and last time at my expense ️️Lol

 

[SparkyChick]

how do I stop them doing their first and last time at my expense ️️Lol

Make it a course pre-requisite that they have their own test gear and that they use it.

I suspect the reason that most of us don't make the mistake very often is because we've blown up our own gear and had to suffer the consequences, which as you clearly know involves spending money

 

[Diver233]

You can get low range current clamp meters, however because you're measuring DC current they will not be as widely available as the AC versions.
Something like this would do:

https://www.amazon.com/General-Technologies-Corp-CM100-Current/dp/B001TCWL1E

Maybe worth contacting the site sponsor test-meter.co.uk and see if they can recommend something for you. You also get a discount for being a member.

Rob you are a genius, the meter arrived today, it works an absolute dream. Had to come from USA and was a bit pricey but no more students blowing multimeters up.
Thank you.

 

[Bobster]

Rob you are a genius, the meter arrived today, it works an absolute dream. Had to come from USA and was a bit pricey but no more students blowing multimeters up.
Thank you.

No problem, like I mentioned though I'm sure someone @Test-Meter could have gotten you an equivalent from the UK with a forum discount applied too.

Maybe worth baring in mind if you need more for your staff.

 

[Diver233]

You can get low range current clamp meters, however because you're measuring DC current they will not be as widely available as the AC versions.
Something like this would do:

https://www.amazon.com/General-Technologies-Corp-CM100-Current/dp/B001TCWL1E

Maybe worth contacting the site sponsor test-meter.co.uk and see if they can recommend something for you. You also get a discount for being a member.

Rob you are a genius, the meter arrived today, it works an absolute dream. Had to come from USA and was a bit pricey but no more students blowing multimeters up.
Thank you.

No problem, like I mentioned though I'm sure someone @Test-Meter could have gotten you an equivalent from the UK with a forum discount applied too.

Maybe worth baring in mind if you need more for your staff.

Now I know it works I will try find in uk, I did message them regards one of their clamp meters to see if it would do the same, they just sent back a data sheet didn’t answer my question sadly

 

[Bobster]

Now I know it works I will try find in uk, I did message them regards one of their clamp meters to see if it would do the same, they just sent back a data sheet didn’t answer my question sadly

Give them a call, I'm sure they would be glad to explain.

Or, post up the data sheet an I or someone on here will tell you if it can do the same.

Edit: This meter is actually quite cheap for measuring DC current like this. Hall effect measuring is a lot harder to produce and be accurate as standard clamp meters.

 

[Diver233]

Rob have a look at

AEMC CM605 Low Current AC/DC Clamp Meter (100A) - https://www.test-meter.co.uk/aemc-cm605-low-current-dc-clamp-meter/

Looks fairly much like the same unit maybe re badged.
If it’s the same as the amazon one it would fit the bill. Checked the amazon one against my new calibrated flukes and it was within a few mA.

 

[Bobster]

Rob have a look at

AEMC CM605 Low Current AC/DC Clamp Meter (100A) - https://www.test-meter.co.uk/aemc-cm605-low-current-dc-clamp-meter/

Looks fairly much like the same unit maybe re badged.
If it’s the same as the amazon one it would fit the bill. Checked the amazon one against my new calibrated flukes and it was within a few mA.

Yes, that will do the job.

Like I said, they look costly but are actually very cheap for what they are doing. So the accuracy is going to be not as good as what the flukes, in series measurement will be. Error will be less the larger the current you are trying to read.

However, it solves your problem, an If they get an errant reading or one that's on the boundaries of being permissible, they can use the fluke to check under supervision if necessary.

 

[Adrian1958]

Good news , Martindale do some good stuff, worth giving them a call.

Martindale Electric Co Ltd, Metrohm House, Imperial Park, Imperial Way, Watford, Hertfordshire, WD24 4PP
T: +44 (0) 1923 441 717
F: +44 (0) 1923 446 900