ammeters / voltmeters

[Kathryn]

I'm needing to purchase some more meters. Any suggestions of where to get good quality meters? We're wanting the bench type analogue meters but it looks as though they may be being phased out for digital models.
Kathryn

[Marama T]

We bought Westlab analogue ammeters a while ago. Seem to be good so far.

[bigmack]

I'll be seriously considering IEC Digital ammeters next time . Sure they are about $80 each but they are pretty bullet proof compared to the old analogue ammeters .We get so many analogue ones that are burned out when they are connected up wrong .Voltmeters are a bit more forgiving .

Only downside is it's another skill the kids don't learn . They are getting so used to looking at numbers . Many can't read an analogue clock

[Merilyn1]

We purchased the IEC digital ones as well. Yes, reading a dial may be a skill that is lost but when I was at school I had a booklet of log tables etc (anyone remember that?) My older brother used to use a slide rule. Some skills maybe lost, sure, but is it a problem?
The digital ones are bomb proof.

[Labbie]

So true bigmack,

[bigmack]

We purchased the IEC digital ones as well.

Merilyn, curious about battery life in them ? What do they use? and how often do you need to replace them ?

[Merilyn1]

That was a good question. I'm sure I checked before buying them but it was seems like so long ago - lockdown does that to you!
So I went and opened one up - just two screws and it has just a 9V battery. Nothing too complicated. We bought them last year and with lockdowns, they haven't been used much. As a result, I can't comment on how long the batteries last. The meters have an auto shut off which will save on batteries.

[bigmack]

Thanks

[melsid]

We purchased a set of analogue ammeters and voltmeters from MTA last year. So far they are lasting well, but of course they haven't had a huge amount of use thanks to lockdowns...

[bigmack]

At my new School and we have about 4 crusty old analog ammeters and a bunch that are burnt out .This is an issue with Analog ones . invariably , one will get connected directly to a power pack and very quickly ....in about 2 seconds ...burnt out .They are then bin material .
I'm trying to convince boss to get some digital ones .
. The IEC ones would be my choice but they have jumped in price to nearly $120 each

Ammeter IEC.png

second choice is the EISCO ones from Westlab and MTA ( although westlab are cheaper ) around $75 each

Ammeter Eisco.png

Then Haynes has a new player on the field at around $65 each .

Ammeter Globe.png

Does anyone have the EISCO ones and how are they hanging in there ?

[Merilyn1]

Ouch - we have the IEC ones but didn't pay $120 for them, maybe $80? Anyway, that doesn't help you now.

Consider the cost of the analogue ones and how quickly they fail.
The IEC ones seem really durable, we have had them a couple of years and had no problems with them. Teachers love them. They seem really kid-proof. If you've got the money, buy quality, or put in the budget for next year.

[littltesttube]

I have the bottom two and have been using them for about 4-5 years without any problems. I check that they are turned off when returned. They use 9V battery.

[bigmack]

The IEC ones seem really durable, we have had them a couple of years and had no problems with them.

I've always preferred IEC over the cheaper versions Merilyn .But the recent price rises has me balking

I have the bottom two and have been using them for about 4-5 years without any problems. I check that they are turned off when returned. They use 9V battery.

Thanks littltesttube
Thats great to hear .
LOL, 5 years is a lot longer than many of our Analog meters lasted

[bigmack]

HOD agreed to buy the IEC ones and today they arrived .
Been curious to see how indestructible they are .

As I mentioned in LabTechBrookes Topic ,viewtopic.php?p=50719#p50719 , Ammeters usually meet their death when students accidentally ( and some times deliberately) connect them directly across the output of the power packs .The maximum current flows through them which is many times higher than they can handle and they burn out in literally seconds .

The operation manual says they have a current shunt that can handle up to 50amps .It's a meaty big resistor as apposed to the usual thin bit of wire used in the analog 5Amp meters .

Ammeter Inside.jpg

So the big test . I did the the unthinkable and connected it across the power Pack output .
On 6 volts , the Power pack was putting out a huge 19 odd amps 4 times higher than a 5Amp meter would have taken . The Power pack clicked off after a few seconds while the ammeter didn't flinch .

I turned up to 8 , 10 and finally 12 Volts . in all cases the Power pack clicked off and the meters overload light flashed on .

But the meter totally survived
So IECs claim of and almost INDESTRUCTABLE meter would ring true .

Ammeter Short.jpg

The caveat is when used with IEC power packs that have short circuit overload they are Indestructible .Likewise if your Power packs have a current limiter .
However , connect one of these across a Car Battery and it will most certainly melt .

I even tried it on a recent Acid /base concentration conductivity prac that was still lying around and it measured the 20mA through a 0.1M/l ascorbic acid solution .

I'm sold .

[mtg]

Are multimeters any good as a substitute? They are so cheap. I have older meters and dread getting them out for junior classes.

[bigmack]

Are multimeters any good as a substitute? They are so cheap. I have older meters and dread getting them out for junior classes.

They can be , but because there are so many switch positions and sockets , they are confusing .
All will have a a fuse to protect the Milliamp current range .Some but not all have a 10Amp fuse for that socket .

The main problem is that the mA range uses the same socket as the Voltage and Ohms ranges . So if the students are measuring voltage but it is accidentally switched to mA range , the fuse will blow . Meaning you will now have to pull it apart and change it .

I made some cheat sheets and laminated them at old school .It kinda helped by showing which position to use and which socket .
I had another one for 10 amp range but cant find it .

Multimeter.png

Voltage.png

Current.png

I made this one last week for a conductivity prac in Yr11 Chem

Conductivity.png

Alas the Word files are too big to upload to the forum but happy to Email if anyone interested .

[Kathryn]

Wow those are fantastic!