AVO ADVERTISEMENT

I had one of these - wonderfully made instruments with a mirror under the pointer to help take accurate readings. A proper moving coil instrument - none of this digital stuff! They don't make them like that anymore!

I still have a Megger insulation tester with a handle that you wind to generate 500 volts. Very popular with torturers I understand - the crocodile grips on the leads being very convenient for this purpose.

Brian

BRIAN
YES IT HURTS AS WELL---SOMEONE MEGGERED ME AT COLLEGE!!!
GOT MY OWN BACK LATER ON THOUGH. HEE-HEE

Meggers were good for charging capacitors up - good fun when they were next handled by the unwary

I worked for a company that made echo sounders for ships, we were told to megger the cables to the transducer on routine servicing, across the cables was the transducer but they forgot to tell people there was a capacitor across/parallel
to transducer, thus the poor old 250 volt working capacitor instantly gave up the ghost!! detuning the circuit and giving weak signal returns. so we all know where ther transducer lives----lots of tank diving followed to replace blown capacitors.
what a pain, the instruction was soon withdrawn.ftf

I had one of these in my kit for 25 years. Used it every time I tested Current Transformers on High Voltage Circuit Breakers. Had to turn it in when I retired. It's probably been scrapped by now for some Digital recording device that attaches to a Lap Top with no need to plot graphs by hand anymore.
Joe.

The Avo meter was the standard test meter of the day. Avo stood for Amps Volts & Ohms and the symbol was the Avocet..a wading water bird.
I used to own one until it wasnt accepted any more for calibrations. I remember the cut out button on a spring used to jump out if you overloaded it.
The American equivilent was the Simpson Meter, not half as good in my opinion, and most Yanks had never heard of Avo anyway.

A variation of the ohmmeter part, known as an E-meter, is or was used to test personality by the Scientologists. I don't know what Tom Cruise's personality is like but I'll bet his "resistance is low".

John T.

Used to use the 250 and 500 volt bridge meggers a lot for locating faults in telephone cables etc. As you have said they used to wake you up if you got your fingers in way when someone turne dthe handle or pressed the button on the more modern ones. Good for drying out cables with low insulation.

Regards
Blair
NZ

I've still got my AVO. Wonderful piece of kit it is! Though must admit, do tend to use the digital one these days.

The Avo was definately not intrinsically safe. The standard test instrument (i think)nowadays is the digital "Fluke" meter A lot more robust than the Avo, which you had to treat with care to avoid damaging the pointer mechanism.