Multimeter

[Dean]

How does a DC clamp-on ampmeter work?

 

[Dean]

Bingo.

There are certain times when an analog meter is best.

Unfortunately, my 50+ year old one failed several years and I have not replaced it.

Sure do miss it at times.

 

[300jk]

I took a look. Thank you. I did not see any probes. Is clamp on only ? Or did I miss something ? Thanks again.

 

[MarkB_MI]

> The HF sampling rate is too slow to measure Alternator volts.

Possibly. Historically, DMMs used <a href=https://en.wikipedia.org/wiki/Integrating_ADC>dual-slope integration</a> A-to-D converters, which have a very high noise immunity. The HF units probably use generic analog-to-digital converters and have little, if any, analog filtering.

 

[John T]

Yes indeed it has a nice set of probes.......and a separate probe for temperature. The Non Contact voltage sensor is on the tip of the clamp on just get it near AC voltage and it goes BEEP

John T

 

[John T]

After 50 years my old Simpson 260 Analog is one of my favorites

John T

 

[300jk]

Thanks again !

 

[circus]

Repeat what John T says but a different meter I'm happy with. Just to confuse your decision.
Kaiweet

 

[John T]

Another MULTI PURPOSE meter looks good

John T

 

[jimg.allentown]

I have to say ...
There is an advantage to keeping the older meters. They had a high voltage AC scale that went up to 750 volts. All of the newer ones have scaled that back to 250 volts. That is why I keep the older ones.

 

[Geo-TH,In]

There are certain times when an analog meter is best.

There are times an analog meter will mess up ECMs.
I needed to set the Throttle positioning resistor to 780mv,
An analog meter loaded the circuit and didn't give me an accurate reading. Instead it killed the engine.

EVOMS have a high internal resistance, analogs take power from the circuit.

I can't find a lot of use for my old analogs. They might work better when measuring alternator voltages if your digital has a small sampling rate..

When do you find analogs work better?

 

[UncleTom]

I can think of a couple times where analog works better. I can test an ac generator with an analog and watch the needle wiggle back and fourth. I dont have a capacitor tester but you can unload the capacitor and use it on ohm scale and watch the needle go up and them back down indication it is at least not shorted such as a condenser for ignition.

 

[Dean]

Of course, which is why I said certain times.

Ever try to measure charging voltage in a system with a vibrating contact voltage regulator using an inexpensive DMM?

Why would anyone use an analog meter in a CMOS system other than to measure PS voltage?

 

[Dean]

Wish I had one.

 

[Jim in LA]

I have one just like that in the original box from Radio Shack. I bought it when I started VoTech school. Bought an Extech DMM off Ebay several years ago not full size but has 1.5&9volt and diode test options and also came with AC voltage detect probe and receptacle tester.

 

[Jim in LA]

20,000 ohm per volt sensitivity loads down high impedance circuits and results in less accuracy. This was a problem in tube circuits. Most DMM are 1 megohm or higher. This was the advantage in vacuum tube volt meters, The higher the input impedance the less loading and a more accurate measurement. I think you can still get analog VOMs with FET high input. You can get a DMM loaded with features at amazingly low prices. Max input voltage is important safety feature when buying.

 

[Jim in LA]

I looked at Simpson 260s a few weeks ago on Ebay and they had some pretty good buy it now deals. Some even had the roll top case.

 

[buickanddeere]

(quoted from post at 19:32:46 02/04/23) Need new multimeter. My old analog is very inaccurate
lately. Have been looking at digital and analog. The
analog was fine for what I do and simple. This is what I
had. Suggestions ?

Tests capacitors . Clamp on measurement of DC current , handy to test generators , alternators , starters etc .

 

[Geo-TH,In]

Good points.

 

[Texasmark]

I had the Simpson mirrowed scale for analog work and for high impedance input requirements built a VTVM from the kit folks...forget their name. One thing I liked about the Simpson was that I could check capacitors with it to some extent. Along comes DMMs and its a different world....except for checking capacitors....which I don't need to do any more.

The little HF used to be $5 yellow one has served me well for many years. Last ones I bought ( I keep several at different locations around the house/farm) were red and had an on off switch rather than rotating the function selector to the top like is the case with the yellow ones.

So, yesterday I am measuring an A23 battery and one of my yellow ones says it measures just under 20V. Really, from a 12V battery, quite unique. I get out another yellow one and it reads 11.xx something volts....more like it....daaaaaa. Take the back off the first one and using the second one measure the 9v battery...something like 5-6 volts...huh....wonder it worked at all. Installed a new 9v battery and retest the A23 and both meters had identical readings within 0.001 volts..... not bad for $5 DMMs I have had for 15-20 years.