Yellow Jacket 69044 Vacuum Gauge, 0-30" Hg/760-0 Torr, 3 1/8"

Yellow Jacket 69044 Vacuum GaugeThis gauge’s Hg scale (inches of mercury) is from 0" Hg (atmospheric pressure) to roughly 30" Hg. That’s 30 inches Hg. Note that 29.92" Hg would be a perfect vacuum, but that’s unachievable on earth. A torr is a unit of pressure based on an absolute scale; i.e., 760 Torr is normal atmospheric pressure and 0 Torr is a perfect vacuum.Yellow Jacket (YJ) says the only way to accurately measure a vacuum is with a digital gauge such as the Yellow Jacket 69075 SuperEvac LCD Vacuum Gauge Full Range Complete In Case – but that’s probably not justifiable for a do-it-yourselfer. I used this gauge during a Pioneer mini-vac install. A digital gauge can precisely display YJ’s recommended system vacuum of 29.882" Hg, but a dial vacuum gauge will only show a rough approximation – and that assumes the gauge is perfectly calibrated. But..., dial gauges cost much less.My gauge, at the maximum vacuum created with a YJ Bullet vacuum pump, moved the needle to within a hair of the 30" Hg end point. That “point” is about 1/8" wide, further indication of the impreciseness of dial gauges. The gauge thus instills confidence that the pump works properly, but it is most useful for leak detection. The needle on my gauge stayed put for two hours after a deep vacuum, indicating no system leaks AND no leaks from the gauge itself. If the needle moved, that would indicate one or more leaks.The Customer Images show the mini-split after the YJ pump created the vacuum – the gauge starts at (no vacuum) zero, but is maxed out at 30" Hg in the photos. My gauge has a red YJ 3 -1/8" rubber boot cover to protect it from bumps. The five stars means that I’m happy with this product – it’s a solid dial gauge. I.e., good quality, needle at rest is zero and deep vacuum at 30" Hg, even though the latter is only an approximation. This is probably as good a vacuum dial gauge as is available. If you want or need precision readings, as would an HVAC technician, get a Yellow Jacket digital gauge.

I use it to check for vacuum leaks. Large gauge. Good quality.

Does not work as micron gauge.

Would not indicate high vacuum beyond 50 Torr. Either I got a defective unit, or as per others comments, it's not capable of reading a full vacuum. Pump used for testing exceeds 0.010 mmHg (10 microns).

I was looking everywhere for an affordable vacuum gauge with 0-760 mmHg range. Lab companies sell them for hundreds of dollars. I got this in a couple of days and attached it directly to 3/8" vacuum hose with a hose clamp and it worked perfectly.Note: Some other reviews incorrectly state that the fitting is 1/4" NPT. The product description is correct, it is 1/8" NPT. This is an unusual size that you're unlikely to find at the hardware store, so you'll probably need to order a matching fitting online.

Absolute junk! During the first use when I got close to pulling a complete vacuum the gauge broke and went back to zero where it wouldn't move anymore. Save your money buy a digital one.

Reads down to a few torr. Some have complained about not hitting the bottom end (below 50 torr) but mine reads below 10

accurate and perfect had a problem with first shipper replaced with out a hang up ,but second one was perfect still works great 3+monthsupdate June 2 : still perfect