What type vacuum gauge

[volcool]

Hey guys,in the market to buy a vacuum guage. Any suggestions on what brand,what to look for etc etc.?

[jpsmith1cm]

BluVac

[hvaceric]

BluVac!!!!!!!!

[Tech Rob]

It is just my opinion, but I believe this one is the best. I don't trust digital gauges one bit.

Thermal Engineering Model 4501

[volcool]

Thanks guys,never heard of bluvac,but looking at it compared to the yellow jacket,i believe ill go with the bluvac

[hvaceric]

It is just my opinion, but I believe this one is the best. I don't trust digital gauges one bit.

Thermal Engineering Model 4501

After using the TE for several years, and then getting a chance to use the BluVac, I will never again trust a TE micron gauge.

[Tech Rob]

What happened?

[hvaceric]

Comparing the two side by side the BluVac:
Registers much faster to changes and at a far better resolution (.1 micron for the original, 1 micron for the LTE).
Speed is not compromised by cold temperatures as with the TE.
Has a built in oil sensor to tell me if the pressure sensor has been compromised.
Can be re-calibrated by putting it on the freezer.
Change rate (they call it leak rate) display that shows how fast the system pressure is changing in .1 micron/second (original version) (I personally disagree with the designation leak rate, because after working with this gauge I have learned that there a lot of other things that can cause the pressure to rise after the system is isolated than just leaks).
And I like the size much more.

It has a bit of a learning curve because of the accuracy and resolution, at first I did not know what I was seeing or how to interpret the readings, but after working with it I cannot go back, it would be like going back to analog gauges after using digital, or an analog meter after the digital multimeter.

[hvac wiz 79]

yellow jacket 69075 ... i had bluvac, prefer the yj.

[Icefixer]

I use the JB DV-41 digital micron gage, I'm happy with it. . I've had the CPS one. Didn't like it.

[Tech Rob]

The key to using the Thermal Eng. gauge is to plan ahead a little and make sure that the tool is at room temperature, or pretty close, when you go to take your reading. Keep the sensor upright and oil won't get into it. This goes for all of them. Quick response is not a factor for me. I take a reading and then come back after a few hours, most of the time between 12-24 hrs., and take another reading in the same spot. If there is no significant rise, then I can start charging whatever it is I am working on. The only time I don't do this is when it's a critical piece of equipment that needs to be back up a.s.a.p.. I understand this isn't really practical if you're doing residential work, running multiple calls, and putting your vacuum gauge on multiple systems every day. For me, I don't need a bunch of gimmicky stuff like "leak rates" and "oil sensors". If it's leaking, it's leaking. You have to open it back up and find the leak. This is just crap that complicates what should be a very simple process.

I've had 4 or 5 different digital gauges. I haven't had really great luck with them. They seemed flaky, even if I handled them gently and cleaned them regularly with alcohol.

[hvaceric]

So you take the gauge off and put it back on the same spot 24 hours later?
What size system?
What about calibration? That can change a lot with temperature.
I have had my TE change the reading by 25 microns just by moving the instrument, not the sensor.
The TE sensor reacts horribly slow, with the large brass mass around a little tiny heater and thermistor, it's easy to see why it can't react fast.

The first time I used the BluVac I was outside at the condenser and the other guy was putting in the evap, when I valved things off to do the rise test I would get small jumps in pressure periodically, 5 to 8 micron rise and back down (I had this system well below 200 at this point), it took me a bit of listening to figure out what was going on, every time he would bump something inside it affected the pressure in the line by dislodging contaminants in the lineset or coil (the walls of copper tubing are not molecularly smooth, so things get lodged in there and come out slowly, which is why triple purging works to help remove contaminants) and make the reading jump, then it would stabilize again.
Now, while I am pulling down I can see how fast things are leaving, as the overall pressure goes down the pressure will fluctuate up and back down, the change rate reading gives me a good marker of how much contamination is in a system by having an accurate reference as to how fast the system is going down, which tells me if purging is necessary again or of the pump can take it out by itself.

I recommend trying the BluVac if you get a chance. I have had and used other digitals as well, none hold a candle to this one. Look up HVACRat on u-tube and check out some of his evacuation videos for a good look at what it can do.

[joeyd]

@hvaceric, @jpsmith1cm: Thanks for the thumbs up!

@hvaceric: you are correct re 'leak rate'. You are not the first to mention this. In hind site, I could have come up with a better term. Perhaps 'delta P' or 'rate of change' would have been better. Regardless of what it's called, its a powerful feature for diagnostics.

@volcool: If you decide on a BluVac, thank you. If you have any questions or problems, I'm always happy to help, either here or over the phone.

Thanks, guys!