Electronics > Beginners

Buying A Power Analyzer Meter

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Ben Yisrael:
Hello Everyone and Shalom !

Sorry if I'm wordy, this is my first 'chat'

I am trying to start a "Green Energy" (read that 'save you power bill money') type company. I am a builder by trade, and my dad worked in Electronic Design & Repair, so I know a little about Energy and Power -- but not much.

I formed a co-op with an Electrician, HVAC Contractor and Electrical Engineering guy from the local Community College, so please see I am serious about my new Business direction.

We sell Power Factor Correction capacitance type products, along with TVSS protection, and Energy Efficient Lighting (Elec ballast Flourescent, LED, etc)..

SO here's the question : I have a True RMS Power Analyzing Clamp meter from Extech (around $ 650.oo)
After I started using it to get kVar readings, I see why they make multiple lead Data Logging meters, but they cost from $ 2100 (Extech) up to $ 5000 (Fluke, Amprobe, etc).

I found a Uni-Trend Power Analyzer (with comp interface) for around $ 200.oo which seemed too good to be true. So I searched for reviews and that is how I found this site.

It seemed Dave liked Unit-Trend in his EEVBlog # 99 " $100 MultiMeter Shootout"

Here is the address for the tool, could someone comment on what they think about this, Please

   Unitrend Meter : http://www.uni-trend.com/UT233.html

Thanx Again  :  Grace and Shalom to You All

Ben Yisrael

I would be wary about 'too good to be true' products, in my experience, there's often a catch.

I'm not into power electronics (my world is mostly <1A and <50V), but here are my two cents:

- Can't find anything about bandwidth of the true RMS converter (only about the range of the frequency counter), this might be really bad, barely above 60Hz. Not sure how much you need, a few kHz probably wouldn't hurt for things with weird waveforms like a switching power supply. True RMS is useless if it doesn't have enough bandwidth to sample the waveform.
- Make sure to flip through the manual to see if it does everything you want. For example, it looks like you can either determine the minimum of maximum, not the min/max/average that many multimeters have.
- Make sure the software does what it should and works under recent and 64-bit Windows versions (it sucks to have to replace tools because you bought a new computer).
- 600V CAT III / 300V CAT IV is not great in my opinion. Even a residential distribution panel is often 400V CAT III (assuming your mains in 230V). If distance between the distribution panel and power entry point is less than 15m or so, it's even 400V CAT IV.
- My impression of Uni-T that's it's usually big on features but built down to a price, I think this was also Dave's conclusion from the $100 DMM shootout. Not a professional tool in my opinion, at least the $100 stuff. But they haven't sent me anything for free yet, so it's purely based on what I've seen and read on the internet.

I'm sure Kiriakos will chime in to explain that Uni-T is the best since sliced bread and is much more EMI resistant than those expensive Flukes ;).

Clamp type might not be the best if you want to measure small powers, say less than 10 watts. Can't really comment on UNI-T, but I recently bought Gossen Metrawatt metrahit energy, a logging DMM with power and energy measurement functions with a power measurement adapter (makes it easy to measure the power consumption of mains pluggable devices) and the IR cable for computer connection. Otherwise it is quite nice DMM for general electronics use, although quite pricey. Of course, it measures true/reactive/apparent power and energy, also with non-linear loads. What I like the power and energy function, the power/energy function is usable to quite small DC powers too:

(the power of 1 M? resistor connected to 3.3 volt DC supply)

OK, I'll stop here, maybe I should write more thorough "review" about the meter to the review section :) (And yes, it passes the "GSM immunity test", but with suffered accuracy during the exposure)


Ben Yisrael:

For clarity sake, I measure mostly (90%) 240/480 v 3 phase motors in Commercial / Industrial settings.

Most motors are 5 hp up - majority are 10 and above


Ben Yisrael


--- Quote from: alm on September 21, 2010, 08:06:26 pm ---
I'm sure Kiriakos will chime in to explain that Uni-T is the best since sliced bread and is much more EMI resistant than those expensive Flukes ;).

--- End quote ---

I can not do that any more , the bribe ( yellow black ) was generous ..  :D  :D  :D
Better than the 87-5  ;)


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