Fan Testing Round 5 (Working Thread)Are "NANO" Bearings the new sliced bread?

[Martinm210]

It just keeps getting better. I bought a used Extech 407123 Heavy Duty Hot Wire Thermo-Anemometer

It was also sort of a for parts or repair, the screen numbers bottom half would fade out. Opened it up and the screen was a little loose and would fade when lifted away. Hot glued it down and all is well..

New, this meter cost around $429
http://www.amazon.com/gp/product/B00...HW67NXTDTTN6NG

But I got mine for $25.99 plus shipping.

Whoohoo another score!!...

Better yet, they have software on their site for free, with all the learning on the old manometer and help here, I quickly figured this one out and have it logging

Now I just need to run a cable under the house and I'll have dBA plus Air flow simultaneous logging..

I do like the hotwire better, this thing is even more sensitive than the omega and completely silent. While the Omega HH-30 is a fine quality instrument, that meta vane is not silent. It would have taken some work to isolate the vane and I wouldn't get logging capabilities.

I'll just save the Omega for other duties and plan on using the Extech. Major step forward..

[Vampiyer]

Oh wow, what a steal! [Heh, but do we know that it's reasonably well-calibrated? - I suppose it's much better than what you currently use, and it should still provide relative measurements regardless?]

I haven't kept up with Martin's exploits lately. What's this I'm hearing about a GT-beater?

You've all been busy!

[Martinm210]

Oh wow, what a steal! [Heh, but do we know that it's reasonably well-calibrated? - I suppose it's much better than what you currently use, and it should still provide relative measurements regardless?]

I haven't kept up with Martin's exploits lately. What's this I'm hearing about a GT-beater?

You've all been busy!

I don't have any official calibration means, but I can compare the meters.

Between the Omega HH-30 and Extech, a quick check gave me roughly a 10fpm difference on a 440fpm reading, so I feel reasonable comfortable that they are accurate (absolute) within 2-3%, and relative should be better and known after a some repeatability tests..

Made a few trial runs this morning and I'm really happy with the Extech Hot wire. There is no lower limit on this thing, even with fans like the D12SL12, I'm getting solid velocity readings at startup voltage, and pure silence.

I also ran the D12SM12 at the beginning and the end of the mini round for a repeatability look. I also have my new sound level meter with A-weighting, so the test rig is finally what I wanted. Fan test chamber V3 is up and running..and getting some trial runs..

I'm not sure what Hondacity has found, not sure you can even buy anywhere yet, or what they are even called, but it's supposed to be really good.

[MagisD]

^^^ he hasn't got his hands on a new fan just made for rads has he????

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[Martinm210]

^^^ he hasn't got his hands on a new fan just made for rads has he????

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Not sure, he's got some leads on some good stuff though. Makes me wonder when he said he wanted to send me a spare so I could take a look at the windings though. Something special going on in there..

Anyhow, ran through one repeatability test. This trial I decided to zero up the anemometer before each test. Test 1 to test two was spot on minus 4 FPM, so I'm going to try another set without zeroing between fans. I thought it might be better to zero out, but I think that's what cause the 4 FPM shift in results.

This is what the setup looks like and my first repeatability test. I need to try this again with one zeroing at the beginning of the round, I think that should fix the shift error I had here. Still not too bad though 4FPM of 277 is about a 1.4% error.

Both sound metering methods seemed to produce fairly good repeatable results.

Also as I expected, my previous meter's inputed duct area and the blockage caused by the vane itself was creating arbitrarily high CFM numbers. Even with this simplified Q=AV calculation nets around 28CFM for the yate, where the previous meter was reading about 36. Since the hot wire probe itself causes almost no restriction at all on the port opening, I believe the 28CFM number to be closer to absolute than the previous arbitrary vane probe numbers.

I also think I need to calibrate the YMEC software dBA gain. The Art meter has an internal calibrator, so I believe it's fairly accurate and my previous software calibration based on the fan spec is giving unrealistically low dbA numbers.

Finally, I got the new Scythe Kaze Master back in place for approximate RPM info. With the 30RPM increments, it's not exactly precision...but still value to have for approximate reference. This time I have it setup patched into just the rpm/ground so I can control the Voltage remotely without having to reach around the camera and setup.

Anyhow, getting it dialed in. Haven't tried any logging yet, but I'll give that a shot as well. The low end sensitivity of the Hot Wire is amazing, I can actually get velocities through the rad with fan speeds of 400RPM and lower...it's amazingly sensitive and best of all...no noise!!