It was once upon the big boss’s visiting a show site that there was a wee problem in balancing the load, and further discovered that not one of the crew possessed a
clamp meter so as to help solve or diagnose the problem. It was than mandated into corporate rule that any employee that wished to do shows should possess a
clamp meter. Ya’ know how simple could that be, I even had one while a carpenter by trade...
Given this mandate which has a
bit fallen to the wayside in requirement
level until next time by way of active memory in what could happen... I set out as the shop tool person to find and study the
clamp meter at the same time as my B&K
clamp meter was starting to give me problems or limited for what I needed.
Did a study of the following:
Model # Brand True
RMS AC Amps DC Amps AC
Voltage DC
Voltage Resistance
Capacitance Continuity Temperature Frequency Peak/Hold Jaw Size
Of this there were a few defining features important. First the seperation of True
RMS that on a computer
dimmer will counter the non-wattage
effect, and jaw size - a 4/0 type SC
feeder cable has a specific diamater and those clamp meters that will not fit over the cable won’t work so well. Add to that amperage
rating of 400A and less, features such as peak hold and max hold, ability to test
voltage both AC and DC, frequency, resistance and have a beep for it,
etc. and you have what will be an all around multi-meter. Add to this some Fluke add on/replacable jaws to one’s probes and you have a really useful multi-meter. As long as bananna clip style probe as another limitation. Beyond this was accuracy and features available.
Below is what I studied and the starting prices from 2003: (given this is a Word Perfect table and it does not translate so well to the net.... Perhaps print if really interested in what I found in this study of most brands of
clamp meter.)
SEE PDF posted below...
Since than, those of the upper tier of people such as me bought the best Ideal (above Fluke) in spec choice for
clamp meter. While we had to get used to it taking a
bit longer to
settle down in zeroing, for the most part it is a good easy to use true
RMS meter. Those stating out seem in the other extreme of budget most often
settle for non-tru
RMS meters of the Extech brand and there is nothing really wrong with them. Accuracy,
RMS and features are at times less but for the price they work well. For those following the rule, it is a good
meter even if the jaws are a
bit small in just able to fit the cable. While one co-worker was waiting for the Ideal
clamp meter simillar to mine was waiting for the thing to just
settle down and zero out he sent me an E-Mail about the thing... What is this crap you specified over Fluke... it won’t zero. Did a study of my own and it does take it’s own time in zeroing, but on the other
hand is much more cost effective, accurate and more important yet does offer more features than the Fluke
line of product. I was really disappointed in what Fluke for clamp meters had to offer. This not to say that Fluke and other brands don’t have a place, just that for the best, at times it is not Fluke. I did the best and they also have full warranty
in one lens breaking under use and it being replaced.
Still beyond clamp meters there is multi-meters that measure amperage. One can even test such a thing
thru a figure eight with one’s probes. Bought
thru McMaster Carr a Extec multi-meter non-clamp
meter or two now that will
meter thru the probes 20 amps and that’s sufficient and necessary to test a follow spot.. Master
ballast testing prociedure for a
Lycian 924
ballast is with a multi-meter that tests up to 20 amps by way of probes into the multi-pin
plug. Far different than testing 400A range on a show this testing with the probes the multi-pin
plug to ensure it will as a
ballast provide the proper amperage. At minimum at work now, I now have two types of amperage meters and ones that the common standard to the industry Fluke #77 won’t do. One to do
feeder cable in the 400A range, plus is true
RMS and very accurate, one that tests ballasts, than one that is analog. Something not mentioned above is the analog
meter.
In an expert in the induststry coming to visit where I work in giving a class, he requested a
meter. Gave him mine, it was not sufficient. Gave him the shop’s old analog
meter and he was satified. Why would one choose an analog
meter over a digital
meter? Analog meters have a sort of resistance that compensates for computers, computer meters I learn don’t. Going for a
clamp meter... go with the best or go simply analog I learn as often even better yet. The old timers use analog clamp meters if they use them - they often don’t in already having solved problems, but non the less it is their magic. Yet to buy one but it is on my own shopping list such an analog
clamp meter. No... Not such a thing as a Radio Shack type
meter in considering it accurate, more like a Spherry type brand and one well respected.
Still the expert in the industry recognized my
meter and did his thing given it’s limitations and slowness to zero. True
RMS and not True he explained
etc. in teaching how to use such a
meter. Beyond buying a multi-meter, this much less just as if multi-meter, one that beyond what the multi-meter does, one that will also tell amps about a cable, one needs physical instruction in how to use it. This much less at least a knowledge of what “True
RMS” is or its use for our purposes where appropriate or in need or necessity dependant upon the person using it.
Multi-meters are a science, beyond this are clamp meters that do what a multi-meter will do yet go beyond that. Cannot imagine the need for say a Fluke #77 these days when a
clamp meter will do what it did in our world plus more.
It’s possible that if one buys a good enough multi-meter, one can also buy the accessory amp clam for it and it’s going to work the same, but one needs to buy a good
meter in the first place, than invest further into it. Cannot see any rational in a
plug in feature that does the same as a
meter that alredy does it however.
On Fluke on the other
hand, Fluke #TL 223... It’s a sort of probe type accessories kit that will work with most brands of quality
banana plug type mult-meter and has a number of probes that
disconnect and reconnect. Great idea - others have similar but not as good. Add onto it with other styles of clip and you now have
ease in testing stuff. Clip the
alligator clip onto one pin and probe with the other. This as opposed to attempting to hold a probe on one pin and test to another without much
ease.
Me, I’m an Ideal
meter person in having replaced my discontinued B&K
clamp meter that I loved and was great. Hz, amps AC and DC amps and volts, ohms and
continuity. Add to this True
RMS, ability to clamp the cable, peak and max hold, than after those options accuracy and you now have a great multi-meter for our industry.