D/C Amp Meter

Re: D/C Amp Meter

Clamp or shunt?

You can get a shunt and wire it into the circuit pretty cheaply.

A decent DC Clamp meter is probably on the order of $100 starting price (and UP)...

-Bill

Re: D/C Amp Meter

Well, in no particular order... (OK, I lied, starting from cheapest )

• Shunts: Basically a calibrated power resistor with a pair of heavy connections for the power, and a pair of small connections to connect a milli-volt meter (I=V/R)

Deltec 100 amp, 100 millivolt current shunt
AC or DC - common item for use with many battery monitors and amp meters

• Next, I really like meters that can measure Amp*Hours and Watt*Hours... To that end, the Watt's UP and Doc Wattson seem to be a good deal. Read the support manuals--they have suggestions on how you can measure current in excess of 60 amps.

For inexpensive clamp on DC Amp Meters, the Extech meters seem to look OK. The MA220 looks interesting at $100 (Jameco Electronics is a couple miles from my home and I have purchased some inexpensive equipment from them over the past decade).

Then there are Battery Monitors (external shunts and multi-function meter heads). The higher end units can have Peukert Factor correction in them too (the higher the current, the lower the apparent battery capacity):

NAWS
Victron

Above that, I have used current probes from Techtronics (decades ago)--great for connection to a oscilloscope to measure exact current wave forms. I have also used a Fluke Meter Current Clamp...

All have their limitations--And I have found (at least for me), the less expensive current probes I have used tend to wonder around zero current pretty significantly.

If I needed to measure accurate/low amp currents (less than a few amps on either side of zero) and log those over time--I would tend towards using a current shunt for its long term accuracy. Also, with a shunt, you can connect various multi-function meters (amp*hour, watt*hour, battery monitors) and get more information about my battery bank's condition over time.

If I needed to just check the current flow through various DC circuits for diagnosis and the occasional checkup--I would go with the DC current clamp (zero, then clamp, zero then clamp, etc.).

-Bill

Re: D/C Amp Meter

GPM,

Lets us know how it works for you--I have been wanting a DC clamp meter for personal use for years... Just too cheap to buy one. :roll:

-Bill