How many multimeters have you got? -

How many multimeters have you got?

Max’s article “What’s the Best Travelling Toolkit?” provoked considerable discussion at the time on the best multimeter for such a kit, started off by reader and blogger Aubrey Kagan (aka Antedeluvian) and contributed to by yours truly. It got me thinking about the multimeters I have owned, still own, and would like to own. These range from simple – and cheap – analog meters to reasonable quality Flukes. Fluke is surely the predominant name in Digital Multimeters, especially hand-held ones, but there are many others. I’d still like to get my hands on one of the revered HP / Agilent 34410A 6½ digit meters:

But for me – installing telecoms equipment at work and doing mainly hobby stuff at home – it would be total overkill and I could not justify the cost of even a second-hand one.

A multimeter is probably the first test equipment purchase (or let’s use the wider term acquisition which covers me) when one becomes interested in electronics, and is probably one of the most memorable ones. Martin Rowe posted a good article on quality meters you can buy for under $150. But I haven’t bought a multimeter for yonks…I’ve just got so many lying around, and I have been given a few as well.

While I was writing this article I took stock of my current meters and find I actually have no less than 15 of them lying around. Recently I got a “job lot” box of surplus stock from a supplier that was moving out of electronics goodies and more into the PC-TV-Phone kind of electronics. In it were 7 multimeters, most of them the “under $10” kind. I sold or gave away most of them, keeping a couple as spares or for use in a breadboard system I am building.

I’ve taken or dug up pictures of some of the meters I have owned, and I hope they will bring back to readers happy memories of their own favorite meters. Click below to see these meters in all their glory.

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Oldies but goodies

My first multimeter was a Japanese Sanwa, a small analog meter, which was given to me by a fellow electronics nut when we were kids – probably about 13. I had to do a fair bit of work to get it working when I got it (which is probably why my friend gave it to me). I’ve long since lost it, but it served me well in my initial years of interest in electronics. This was so long ago now that I have forgotten exactly what it looked like, but it was very like this one. I still remember wondering what the strange dB ranges were for….

My next multimeter was a Kyoritsu (KEW) K-1400. I got my dad to get it for me on a business trip to South Africa, from an electronics supply house in Johannesburg called Hamrad, which South African readers may recall (they are still going!). I still remember the thrill of unpacking it from the box. It was a reasonably professional meter – 20 KΩ/V and a mirror scale. The one above is branded Eagle but mine looked exactly the same otherwise. I left it behind when I emigrated from Zimbabwe to Australia in 2002, and it vanished, a pity as I had a very sentimental attachment to it.

When I started work in the radio section of the grandly named British South Africa Police in the then Rhodesia (as a conscript on National Service, though at least I got the choice to go into the radio section), we were issued with an Avometer. AVO (named for Amps-Volts-Ohms) were the predominant British meter manufacturer. Avometers were very rugged and almost indestructible and were still produced until 2008. For field work they were bulky and heavy and for bench work they were difficult to read, and they would not be my choice of instrument for either. But they are like Landrovers – they are not the best four-wheel-drive vehicle, but anyone who has used them will remember them fondly. Many older Engineers will simply call a multimeter an “Avo”, such was their ubiquity. They were first produced in 1923 by The Automatic Coil Winder and Electrical Equipment Co. Avo has now been absorbed into the Megger group. There is another ubiquitous brand name: many people call any instrument to test insulation resistance a “Megger” no matter what its provenance. But I digress….

This is a Keithley 130A, the first Digital Multimeter I ever owned, and I bought it new in the late 1970s I think. It is still going strong. I keep it in Zimbabwe and use it on my infrequent trips there. There was a guy called Keith Lee in my section, and I remember showing it to him: “Hey, Keith Lee, come and see my Keithley!” Keithley is still going, part of Tektronix, and still making good gear.

AC current meters

I don’t know whether most engineers would class this as a multimeter, but it measures AC current (with a clamp – non-contact) and voltage so I’d allow it in. Tandy in Paris had these on special for 20 francs – a couple of dollars – years ago and I bought 4. I sold 3 back in Zimbabwe and made handsomely on the deal and kept one for myself – it’s still back in Zimbabwe and is cleaner than this one! Years later I worked as an electrician for a while and it was my main meter – when you’re dealing with the mains, voltage and current are usually the only parameters of interest. Again – no batteries!

Here’s a slightly more modern version, but still about 20 years old. It was being thrown out as it wasn’t working. I opened it up and found a DVM chip, a few other components and an LM324 quad op-amp. I replaced the LM324 and it works – thought it still needs a bit of adjustment as it does not Zero properly. Hioki were able to supply me with a service manual as well – support for products this old always greatly endears me to a company. The modern versions of this type of meter are full DMMs and many can do just as many measurements as their non-clamp cousins. But they need batteries!

Old school analog meters

I came from an era where multimeters were usually analog, and the one big advantage of them was that for voltage and current measurements, batteries were not needed. You did need them for resistance, but even when the batteries were going flat you could usually get a reasonably accurate measurement by adjusting the Zero knob and/or a bit of interpolation and mental correction. I still have a couple of the small, cheap analog meters – because they don’t need a battery to work properly they are ideal for toolkits where they may not be used very often, and the lack of pinpoint accuracy is usually not a big deal. I bought a few of these in markets in London for the equivalent of a couple of dollars. This one’s got battery test markings and a mirror scale! But only 2 KΩ/V…

Another analog meter – a little bit bigger than my old Sanwa and a bit better quality. This one was also getting chucked, even though it was working perfectly, and was far too good to end up in landfill. But I hardly ever use it. Nice ranges, 20 KΩ/V, mirror scale, and fairly portable. By the way, ever wondered why meters like this have an “Off” position on the switch? It puts a short across the meter movement, which damps the movement and lessens the chance of shock damage if it dropped or knocked.

Low-cost DMMs

Now we come back to the DMMs. This is representative of what you get for ten bucks or less. Reasonable accuracy, usually with diode and transistor test, and if you are lucky, a 10A Current range (this one has), Capacitance test ranges (not on this one), and a continuity beeper (also not). But if they go wrong, you’d usually just chuck ‘em. I have repaired a few, usually with things like PCB track damage from leaking batteries or cracks from being dropped, but any damage to the LCD or the range switch mechanism usually renders them unfixable, physically and economically.

This is the opened-up back of a DMM very like the one above. Note that the PCB was designed for the ubiquitous ICL7106 type IC, but they’ve used a die on a thin PCB instead of the IC – to save a few cents no doubt. Note also the 10A shunt at bottom left, with a couple of nicks for calibration. Cheap, and a bit nasty, but good value and they do an amazingly good job.

This one was also getting chucked out, I’m not sure why as it’s a nice meter. I think its owner had left and the new owner didn’t know what it was. Great display, huge figures and a bargraph indicator, and capacitance, transistor and diode test ranges. I’m saving this for when I am old and decrepit (alright…. MORE old and decrepit 🙂 and I can’t see anything smaller. Here it is measuring a small capacitor.

Small but potent

Multimeters have got smaller over the years and you can now get pretty small ones. I wouldn’t be surprised if someone has made a watch-meter, but I haven’t got one that small yet (and where would you put the probes?). This is the one I touted on Max’s toolkit blog – from Jaycar. The size is 94 x 46 x 26 mm (3.7 x 1.8 x 1 inch) – but at an inch thick it is not quite pocket sized, and it does not come with a case to protect it and hold the leads. But it is a fairly full-featured little meter, with DC Current ranges up to 10A, diode and transistor test and – best of all – full sized 4mm banana sockets, so you can easily buy or make a set of alligator clip leads for it. You could probably get a small camera case from a $2 shop to hold it and some leads. Excellent value at under $5 – as little as $2.50 each if you buy 6 or more and live in the States (which I don’t – mutter mutter). If you compare it with the first standard DMM above, this one is labelled QM1502 and the other is QM1500, and they both have exactly the same ranges. So probably from the same manufacturer.

Several manufacturers make a “Credit-Card style” meter. Tenma make this one which I have. It is fairly small, but not Credit Card sized (4-1/4 x 2-1/4 inches, and ½ inch thick) so it would just fit in a shirt pocket. And it comes with a protective case and lead / probe holder. The Amprobe DM78C is very similar in size. Both of these meters only measure voltage and resistance, no current, which can be limiting, but this one does frequency and duty cycle, and has hold and relative buttons. I had a smaller one than this once – not that much bigger than a credit card – but it was also pretty limited and did not survive long. These small meters have leads going straight into the meter and they are almost guaranteed to fail at this point sooner or later.

This and that

This is the best meter I got in the job lot referred to above. It’s an Automotive test meter and should come with a test probe (I didn’t get that but could make one if necessary) that wraps around one of the spark plug leads on a car and gives you an RPM reading. It can also do Dwell, duty cycle and low frequencies. It also has a type K Thermocouple socket and will measure temperature. So I got a thermocouple for 10 dollars from Element 14 (Farnell / Newark) and Hey, Presto, I have a temperature meter.

I got the software and PC connection lead for this meter on a clearance table for $5. I hunted down the matching meter on E-bay for $60 and I now have a data logger. It’s still a very classy meter, and has all sorts of unusual ranges – frequency and duty cycle, capacitance, temperature (via a thermocouple adaptor as shown) and even a 4-20mA range – and features – hold, relative, recording of minimum, maximum and average readings (within the meter – the software does full logging), peak reading, a backlight and a magnetic clamp to hold it onto anything steel. I also downloaded a VI for Labview that is supposed to work with it. Martin Rowe’s article had a similar one to this here, now made under the Amprobe brand. 

This does not truly count as a multimeter, but it looks and works so like a DMM, and is so useful, that I am including it. It is an LCR meter. Only $50. My wife got me this as a birthday present a few years ago. It’s not as good as a professional LCR meter, for example you can’t set the test frequency, but great for quick tests of components, and you can make a good estimate of transformer ratios with it. Here it’s measuring the inductance of an audio transformer. I’ve also shown a tweezer probe I use with it – really handy for SMD components and only a few dollars. 

My pride and joy

This is my Fluke 8050A, my pride and joy. Bought new in the early ‘80s – when I cleaned it recently, a price label saying $375 fell out. I still have the original soft case with a tray at the top for leads, etc, and the manual, and even the box it came in. I’ve had to replace the display once, this one is still good. 4-1/2 digits, and it has dB and conductance ranges in addition to the usual voltage, current and resistance. It also has a “Relative” button, which when you press it, gives you a measurement relative to what you had at the instant of pressing. Really useful when you are testing low value resistors (it nulls out the resistance of your test leads), or checking the cells of NiCd battery packs. Measure the first one, then click the REL button and measure the second by moving only the positive probe. Click the REL button off and on every measurement and you can get through a whole multi-cell pack in no time. Or you can match several resistors from a pile – measure the first, press REL, and only keep those with a small difference from the first. The only thing I would like on this meter is a continuity buzzer, apart from that it is still a great meter.

In their manuals, Fluke give a diagram for a simple transistor tester attachment that works on one of the conductance ranges and gives a readout of Hfe (you just have to shift the decimal point 3 places to the right). I built one and use it often. Here it is measuring an NPN transistor (a BC 548) with an Hfe of 373.8. You plug it in the other way up for PNPs. You can use the clips as shown or I have a socket on the right hand side, not visible here. Note the embossed Dymo labelling – shows how long ago I made this!

Fluke is another company that has good support even for decades-old products. I still have the original manual for my 8050A, but someone gave me its little brother, the 3-1/2 digit 8010A, and I was able to download a service manual for it. Both these meters have had the LCDs go bad, and I have found replacements for both. There are also mods on the net to replace the LCD with 7-segment LED displays. I keep these DMMs on my workbench and use both of them all the time.

What to consider when buying a meter 

Before I finish, a couple of things to consider when buying a meter. Meters have a “Category” rating – 1, 2, 3 or 4, defined by the International Electrotechnical Commission (IEC). Cat 1 is basically for low voltage electronics use and is not really used. Cat 2 meters can theoretically be used for measuring from a mains wall socket, but anyone doing this should really get a Cat 3 (building distribution) or Cat 4 (utility connection) rated meter. Agilent has a good handout on this topic. Most of the smaller and cheaper DMMs above would only meet CAT 2 specs at the most, but the red Meterman XR38 (above) has Cat 3 and 4 ratings. If you are doing any work on Mains voltages you should make sure your meter is Cat 3 or 4. This usually means buying from one of the higher quality manufacturers like Agilent or Fluke, and you will pay more. The Cat 3 or 4 ratings mean that should there be a voltage spike on the mains while you are measuring, it won’t arc through the meter or the leads and zap you. Since this could ruin your day, it’s a point worth noting.

A magnetic holder with a “carabiner” style clip can be useful for holding your meter at eye level when there is nothing to set it on. You may need to fashion a loop of something on your meter case to clip the carabiner to, but it’s worth the effort if you use your meter in such places. I use them in radio sites, attaching the magnet to the steel rack frame to hold the meter in easy view.

Many people are puzzled by the “X ohms per volt” rating of analog meters, as shown above. It’s simply a measure of how much they load the circuit under test. If the basic meter movement is 50 mA, the resistance needed to get a current of 50 mA at 1 volt is 20 KΩ. So if you get this meter to measure 2V, the total resistance (of the meter plus the “multiplier” resistor) will be 40 KΩ. So it is specified as 20 KΩ/V. If you get it to measure 100V, the resistance will be 100 x 20 KΩ = 2 MΩ. It’s a quick and easy way of calculating what the load of the meter on a certain range will be. This was a lot more important in the days of tubes / valves, where impedances were generally higher than with transistor circuits. I have seen a 50 KΩ/V analog meter but 20 KΩ/V was generally considered good, while small cheapo meters can be as little as 1000 Ω/V. The mini analog one shown earlier is 2000 Ω/V. Digital meters have no such limitations and usually have an input resistance of 10 MΩ.

Meters with a diode measurement range (usually indicated by a diode symbol) should be used on this range for testing diodes – if you don’t, the voltage across the probes may not be enough to forward bias the diode. The reading is indicative of the diode type – around 0.6 to 0.7 for silicon, 0.18 to 0.4 for schottky, and 0.2 to 0.3 for germanium, though the decimal point placement may vary.

If you take measurements in confined places, a “hold” feature can be useful, to hold your measurement until you can see it. Some manufacturers now make a wireless display that can be removed from the meter, very useful also in such situations. And almost all DMMs these days have a continuity ”beeper” – useful for testing wires in a cable without having to look at the meter.

Being of British descent, and having spent my life in ex-British colonies, I have never owned, and not mentioned, the Triplett and Simpson meters so beloved by American engineers and service people. Max’s newly discovered meter repair shop specializes in these meters. But everyone has their favorites – I’d be pleased to hear your stories (and see pictures) of your favorite meters and why you liked them so much. And how many you have!

9 thoughts on “How many multimeters have you got?

  1. “DavidnnWe have many DVMs running around work. Most are long in the tooth, and the most popular re the Fluke 8060A. This is certainly my favourite DVM and the only problem I have with it is that it is a 4 1/2 digit device. When measuring a 4-20mA loop,

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  2. “DavidnnAh yes, Hamrad- as the name suggests, they specialised in ham radio. I remember going to their store in downtown Johanneburg, and in fact I later worked with an ex-employee.nnTheir moves seem to have mirrored the changes in South Africa. They

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  3. “I have 4 multimeters at home:nn1. an analog Kaise meter. It has been surprisingly robust, these 40 years.nn2. FLuke 8020A. Also has held up well although the plastic is yellowing. The user manual also describes how to measure the forward gain of trans

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  4. “Hi David, Your Sanwr analogue meter looks very much like my faithful TMK probably just rebadged. I over power the first one but recently got a good condition one at a car boot last week. The Avo meters were a problem when the original Ever Ready batteries

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  5. “Hi David, Quite a nostalgic look back at the variety of multimeters that have been available over the years, some of which I recognise and plenty that I don't. nnI currently have 2 digital multimeters:nn1. Precision Gold Academy PG -17 that I have had

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  6. “@Antedeluvian, I thought you'd remember Hamrad. Lovely shop if you were an electronics nut. There was another one in Durban, A1 Radio I seem to remember, which was like one huge bargain bin. I still have a pair of VU meters I got there, in their origin

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  7. “Hi again Aubrey…I looked up the Fluke 8060A and it looks like the little brother to my 8050A, but it does Hz and has a continuity buzzer as well…nice. I take your point about the range change when measuring around 20mA, it can be annoying.”

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  8. “Crusty…The AVO overload protection was the best I have seen in a meter, physical disconnection of the movement. I never had any of the Sinclair test equipment but remember the adverts for it in Practical electronics and the like. I have a great respec

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  9. “HI Steve, thanks. Those QM1502 meters seem to be everywhere. Max bought a bunch of them in the states really cheap last year. They are amazingly good value.”

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