Multimeter help needed

[Deleted member 26818]

I think, that unless you insist all student supply their own meters, you’l just have to factor in replacing fuses into your pricing structure somehow.

 

[davesparks]

Make them all aware that they will be charged if they damage the multimeter

 

[KWCFC]

I've been working in security for 5 years and still do it... you've got no hope mate lol

 

[Lucien Nunes]

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.

 

[ian.]

I replaced the low current range fuse with a resetable one for this exact reason: https://uk.farnell.com/c/circuit-protection/thermistors/pptc-resettable-fuses

 

[ian.]

I replaced the low current range fuse with a resetable one for this exact reason: https://uk.farnell.com/c/circuit-protection/thermistors/pptc-resettable-fuses

 

[Lucien Nunes]

That's a pragmatic solution, but the minimum resistance of a Polyfuse that has a low enough trip current to protect the shunt, is likely to have a higher cold resistance than the shunt itself, and much higher than the conventional fuse it replaces. If one needs the lowest possible voltage burden from the current ranges, it's something of a compromise.

 

[MJPD29]

My fluke doesn't need leads changing for any tests

 

[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.

I have ordered one of these from USA so will let you know how accurate it is when it arrived.
Thank you all for your input.

 

[Diver233]

My fluke doesn't need leads changing for any tests

Which fluke is it I’ll have a look

 

[MJPD29]

Which fluke is it I’ll have a look

Fluke 116, hopefully it will do what you need I've been impressed with it

 

[alasdairp]

Fluke 116, hopefully it will do what you need I've been impressed with it

The Fluke 116 only measures up to 600 microamps (AC or DC). i.e. 0.0006 Amps. That is while the rotary switch is adequate. It won't suit here at all!

 

[MJPD29]

The Fluke 116 only measures up to 600 microamps (AC or DC). i.e. 0.0006 Amps. That is while the rotary switch is adequate. It won't suit here at all!

Ok alasdair calm down only trying to help

 

[alasdairp]

Ok alasdair calm down only trying to help

Sorry - I felt calm enough at the time! Few glasses of home-made red wine inside now and I am certainly calm. The 116 is an unusual meter for electrical work - more an electronics multimeter. In fact I was amazed that it only goes to 600 microamps.

 

[Adrian1958]

i am hoping you may be able to help. I’ll try to explain my problem, any help gratefully received.

Part of what I do is train fire alarm engineers and as part of the practical is battery calculations, which we need to measure the stand by and full alarm load off the battery leads.
So the process is swap leads to mA position and switch to mA reading, connect leads in series to the battery disconnect main power so now mA is displayed for stand by the press sounder button on fire panel and you have alarm load.

Despite every time explaining not to do anything different & not to do it until I say etc etc nearly every course some one will either not change the leads or something stupid and bang as a minimum fuse blown.

What I am asking, is there a multimeter that does not need leads switching or as some sort of non fuse blowing feature that will allow non listening people to not blow meters?.

Maybe you need to start the course with some basic use of test instruments.
How to measure Volts , Amps , ohms , difference between AC and DC , lead swapping etc.
When i was responsible for teaching mechanical service engineers basic electronics , i started the training on how to use test instruments multimeters , oscilloscopes etc. All instruments were labelled with , CHECK TEST LEAD CONFIGURATION BEFORE CONNECTING TEST LEADS TO THE CIRCUIT.
Its education from the trainer.
It sounds like its a regular mistake by students and it shouldnt be with the correct training, yes a mistake will happen, but this should not be occurring on a regular basis.