Analog Marconi voltmeter, 1941.

[RobertArthur]

Too cold and slippery outside, too many electronic meters inside. To escape the relentless stream of disturbing news reports, I decided to do something else. Not particularly useful, but it keeps you busy for a while.

Just for fun, I put one of my oldest voltmeters on the test bench. A Marconi meter manufactured in Canada at the beginning of the Second World War (1941), now around 84 years old. After reading the instructions on the bottom (handy) I connected it in the 3 V range to a voltage reference source. And still spot-on with 2.5 Volts on the lower scale.

[Hotrodder]

Magic!

[RobertArthur]

The magical mystery tour continued. Now to the French patrimoine électrique. An AC/DC voltmeter manufactured by the venerable company "Pekly". A design from the mid-1930s, but probably a production series from around 1950 given the use of a Pertinax printed circuit board. "Pertinax" refers to a common, early laminate (paper/fabric impregnated with resin). It's readings are a bit optimistic, upper black scale, 15 V range: 7.7 V DC where it should be 7.5 V. It is likely that a few old carbon resistors in the voltage divider have changed slightly in value, but it would have to freeze and snow heavily for a month before I would venture to do any fine-tuning. Back to my private museum. Where the dimensions and weight of this bench meter(1.034 kg) only really stand out when you see a cute and elegant Italian-made portable multimeter (90x90x30 mm and 144 grams) next to it.

[Hotrodder]

Never seen anything like that little Italian job.

[RobertArthur]

To continue this trip down memory lane in the direction of old measuring equipment. Your attention please for jobs made in France and the USA. Another nice multimeter from France, a Metrix MX 222. On the back a surprising detail: the batteries are easy to remove (separate compartment, two screws) and there are plenty of spare fuses on board. I have to admit that, on this point, the French were a few decades ahead of the Yanks at Fluke. With the older Fluke multimeters, replacing those tiny 9-volt batteries is always a fiddly business. They've improved things since then, take this Fluke 114 and its 9 V battery compartment, only one screw. But still: what took them so long?

Now that we've arrived in the US, let's head straight to New York City in the 1940s. Price in first year (1944): 21.00 USD. Dimensions and weight: 78 x 54 x 149 mm / 0.795 kg. A more convenient size than that heavy Metrix device, more intended for the workbench.

To conclude: lessons learned, a cute, ultra compact pocket-sized cheap and very precise Fluke 101 multimeter with separate battery compartment for two AAA batteries, easy to open. Solid as a brick, size only 130 mm x 65 mm x 27mm, weight: 160 g. Electrical safety and overvoltage protection: picture perfect: 600 V, CAT III. Bonus: one of the best performing range switches available.




















Same size (130 mm x 65 mm x 27 mm). not the same price. There are many would be Fluke look-alikes for sale in China. Some with downright disappointing performances, others surprisingly good.

Pictured (right) is the Zoyi 100, available under different names. Here the Bside Z100 from Hong Kong. A bit to my surprise it is very accurate in all its ranges. Nice display, in this version 4000 counts (6000 and higher versions also available). Two tiny ceramic fuses on board, also a single PTC for overcurrent protection. I didn't see MOVs for overvoltage protection. For electronics a perfect little meter, current measurements also possible. In a 230/240/400 Volts environment I prefer the proven reliability and security of a Fluke multimeter.





Can it be any smaller? Of course, for example this French multimeter from Chauvin Arnoux, which has been on the market for more than ten years now. A real pocket multimeter, but with slightly less precision than the Flukes or their Chinese lookalikes. A not cheap: 204.99 € (Conrad France).





That little Chauvin is a bit on the pricey side, because for 50 euros more you can buy an electrician's best friend, a medium sized Fluke 114. What's more, it's great at hunting down ghost voltages.