Induction type amp meter

[missinginaction]

Hi Folks,

Well, it's almost time to thaw out up here in New York and get back to work on my Silverton restoration project. One of the first projects is to rewire the electrical system and install new gauges in the helm that I built last year.

I found a web site the other day that featured an amp meter that uses induction to measure current rather than the typical shunt arrangement. It looks pretty slick to me, and I was curious as to weather anyone out there had any experience with these meters. I'll post the link to the instruction sheet for the meter below.

Regards, MIA


http://www.wemausa.com/specifications/IAM50-80-instructions.pdf

[CDK]

That type of ammeter is widely used in the industry because the measurement is non-invasive. Disadvantage is that you cannot measure small currents and wires must not be close together because the field around adjacent wires influences the meter readings.

[Rick Willoughby]

Just a fine point but DC meters do not use induction. They rely on the Hall effect:
http://en.wikipedia.org/wiki/Hall_effect
ttp://www.powerstream.com/DC-clamp.htm

Down the page of the second link you will see the sort of range and accuracy possible. I doubt that you need better accuracy or smaller range.

If your unit is from a reputable supplier it should be fine. Even if not accurate in absolute terms it will give good relative reading.

I was tempted to buy one of these meters for my electric boat application and may still do. At present I only go to 10A so I purchased an AUD16 meter from Tandy. These have an internal shunt. You can get good shunts from the electric car places that are used for high current systems but then you have all the hassle of lugs and terminals. Not difficult if you are wiring from scratch but a real pain just to get a current reading.

Rick W.

[missinginaction]

Thanks much to CDK and especially Rick Willoughby for the insight and education on the Hall Effect. I followed your links and learned something new today!

Appreciate the education. I'm going to give that Hall Effect meter a go.

MIA

[pila]

Those type of ammeters were used in the 30s by Ford. They seemed to work OK. The gas gauge on my Dad's 34 Ford didn't work though. It had a glass column like a site gauge, never did know how it was supposed to work.

Some of the older airplanes I work on have the shunted ammeters. No heavy wire to the panel, and weight is a big factor.

[thudpucker]

I had one (in the 50's) that was used in trouble shooting starters. I yoked the source to the starter and would measure several hundred amp's the starter would draw. It was also sensative enough to measure the Generator or Alternator supply.