Clamp Meters/Amp Probes for Electrics?
Posted 18 August 2008 - 08:44 AM
Posted 18 August 2008 - 09:31 AM
I use an Extech 820 DMM with amp clamp. It's a true RMS meter and I have tested it against a friend's Fluke a while ago and it held up pretty well. I use it on jobs and when building electronics/electric stuff too. So far, after over two years it has never let me down.
But I kinda like Flukes, my friend's meter is at least 20-25 years old and still works like a charm. I wonder how long mine will hold. And my basement was flooded recently and my Fluke power probe was completly submerged. And it still works after I dried it up!
Posted 18 August 2008 - 05:53 PM
Posted 18 August 2008 - 06:48 PM
Posted 18 August 2008 - 09:14 PM
Posted 27 May 2015 - 01:10 PM
I need to buy a clamp meter/Amp probe for a film coming up that i am gong to be working on and I was wondering what kind of meters you guys use when working on a film? Do you best boys use ideal clamp on meters, fluke meters, amp probe meters? What is the best kind of meter to go with? I was thinking about getting the Ideal 61-704 clamp meter because i think this would suit all of my needs. What do you guys think?
I know it is too late for Sean, but I thought I would update the archive for future searches. The brand doesn’t matter as much as the method of calculation used in the meter. All of the commonly used types of multi-meters are calibrated to give an “RMS” value for the measured signal, but arrive at that value using a number of different methods. Unfortunately, most of these methods assume the waveform to be sinusoidal and so when used to measure nonlinear voltages and currents, errors occur that result in false readings.
For example, in an IATSE Local 481 Power Quality Workshop I developed we do an exercise where the students meter the voltage and current on a putt-putt generator (non-inverter type) while running a non-pfc 2.5kW HMI light. Since, invariably, the meters brought by the students range in quality, the readings they get range from being 84% over to 40% under what they should be. Since the consequences of under measurement can be significant - overloaded cables may go undetected, bus-bars and cables may overheat, fuses and circuit breakers will trip unexpectedly - it is important to understand how meters work and why only meters based on "true RMS " techniques should be used on power distribution systems supplying nonlinear loads.To see why use this link.
Guy Holt, Gaffer
ScreenLight & Grip
Lighting Rentals & Sales in Boston