Micron Guage Wars

[lenb]

Pictures were lost from previous post, so here's the last round -




Auto a/c compressor test stand




2 year old Inficon, couple week old Supco, and coworker's brand new Yellow Jacket guages on system, has been blanked off for half an hour.




Yellow Jacket 1640, Supco 680, Inficon 4790


Returned the Supco for credit and ordered my own Yellow Jacket which arrived the next week. Next round -




A test room which was disassembled, moved from another facility, and reassembled here by other contractors. Our responsibility is to get the refrigeration equipment up and running. Compressor sections are up on the balconey.




Both Yellow Jackets and Inficon xmas treed off of same manifold




Yellow Jackets both read close to the same, Inficon reads almost double.




Was having trouble pulling down high stage system until I found a valve closed on the cond. inlet which meant that I wasn't pulling much from the high side of the system. When I opened the valve, the pressure at the manifold shot up close to atmospheric. Both Yellow Jacket guages indicated the change immediately, but the Inficon hung up at 21,000 microns.

I'm definitely sold on the Yellow Jacket micron guage, by far the most accurate and responsive I've ever used. Finally feel confident about the readings I see, has eliminated a lot of guesswork.

[chillrdude]

Interesting post Lenb, I have never been a fan of the electronic micron gauges but the yellow jacket looks like it might be OK, I dont know if I could ever give up my mercury manometer though. Good post

[coolwes]

Excellent information! Thanks.
I guess at some point we are going to have to trust all of this new fangled electronic stuff.
From what you are saying, I think I would go with the Yellow Jacket too.
I used one of the old Robinair analog vacuum indicators for years.
It did ok but most of the time I use a wet bulb indicator or, as Chillrdude mentioned, a mecury manometer.
I guess I just feel more comfortable dealing directly with physics. Although it is a little difficult, with my old eyes, to read the marks on the manometer when it's down around 2mm.

[DaleP]

I will still keep my Thermal - analog micron gauge. I'm just too anal.

[lenb]

I had a Robinair analog guage for years, the case was duct taped together, and I had to open it up and jiggle the 8 D batteries to get it to work, and spent a lot of time questioning the readings lately, so I gave up on it.

After trying other guages, I was thinking of giving up on electronics and going with a mercury manometer. But I wondered about the resolution on a manometer, that is, how much of a change in vacuum levels could you see on the manometer during a blank off, if 1 mm. Hg = 1000 microns.

So far I'm satisfied with the Yellow Jacket, hopefully it won't also start acting up after using it for a while.

[will 2]

I've been somewhat shopping for a new micron gauge myself and have done a lot of reading/comparing in the process.

Something that caught my eye while reading the specs on the 69075 was the minimal operating ambient temp of 32 degrees.
And another YJ 'lower cost' model was at 40 degrees.

I'm going to have to go back and reread the 'others' as I don't remember seeing this spec.

Should I be even concerned ?
All of my work is outdoors, so what ever ambient temp is...

[chillrdude]

Correct me if I am wrong, but I believe these electronic micron gauges we are talking about all work with a thermister that as you pull a vacuum it measures the system temp and converts it to a theoritical corresponding vacuum level. If this is correct how can ambient temps not effect the operation of these things. I would think low batteries would also cause erroneous readings as well.

[square2round]

Interesting pictures.

I bought the Yellow Jacket 69070 last year. It's the best one I've purchased yet.

Chillr...the Yellow Jackets model #69070 and #69075 use the thermocouple sensor. It's suppose to have a more accurate reading rather than with thermistor sensors, like the old digital robinairs in the black box. That was a piece of junk. You can read about it here.

So far...the Yellow Jacket has done me well too.

Originally posted by will 2

Something that caught my eye while reading the specs on the 69075 was the minimal operating ambient temp of 32 degrees.
And another YJ 'lower cost' model was at 40 degrees.

This Yellow Jacket uses the same thermocouple sensor and it's rated for -30° - 150°.

http://yellowjacket.com/prdetail.cfm...=15&Auto=1#a17

[270wsm]

What about the NEW Inficon. Its suppost to be super accurate. Anyone tried it?

[staticpressure]

Your tests of the Yellow Jacket backup what I have found out the hard way in the field!! I had a yeloow jacket and it worked great. When I got my "new" truck the electronic micron gauge that was purchased was a lesser (cost)known brand. I had a terrible time trying to vacuum down a set of new compressors I had replaced on an RTU thinking that I had a pinhole leak somewhere. That was until I had one of my buddies stop by the job with his Yellow jacket and we checked the unit and found out that my new micron gauge was reading 700+ microns too high!! In my field experience as well as with your lab tests, you can't go wrong with a good Yellow Jacket electronic micron gauge.

[caosesvida]

Originally posted by chillrdude
Correct me if I am wrong, but I believe these electronic micron gauges we are talking about all work with a thermister that as you pull a vacuum it measures the system temp and converts it to a theoritical corresponding vacuum level. If this is correct how can ambient temps not effect the operation of these things. I would think low batteries would also cause erroneous readings as well.

I belive you are right, I would guess they have an internal temp sensor for ambient if needed. Also getting any amount of oil on sensor will give false readind.

[caosesvida]

The yellow jacket may be the best, but to do an actual test you would need to actually know the real level, I think in reality we are reading a relative value of vacuum.

[coolwes]

lenb,
I gave up on the batteries in the Robinair and installed a jack that I could plug a wall wart power supply into.
It served me well. it's somewhere in my basement now.
Thanks again for the great photos and info.
wes