Anybody got pros or cons on these things. Indoors, mine works great. I have a JB. I noticed everytime I use it out on a job it acts funny. One time, it read 650 microns after working all it wasy down and then it jumped to 2100 and never moved back down. Even hovered around close to 1, which means atmosphere on this one. It has done this on many different jobs, but I have come to the assumption that the heat affects this thing. I would always make sure a vac holds, no leaks, then let it run all night and call it good in the morning. I just started messing around with these things and I think I now know why all the people I work with never liked them.
I use the analog type. I forget the name brand but it is very reliable and it shows me if i start to lose my vacuum. the digital ones, i have used a couple , the JB i think you have is the black one with digital read out. i always had the same problem with it jumping around. i also used a supco i think, it just had led lights. i have use the analog one for the past 10 years. it shows me exactly whats going on.
SUPCO Micron Gauge
I have a SUPCO digital gauge that I've used in both indoor and outdoor situations and it has always been accurate. I don't recall the model at the moment, but it's the one with a remote sensor connection that I can position above the vacuum pump so it doesn't get affected by oil and other contaminants.
SUPCO fo sho
I have always used the Supco VG 64.
-Fairly simply electronic device
-Standalone, not like fieldpiece
-easily cleaned with isopropyl alcohol if needed
-various different unit types
-Sometimes deciphering the atmosphere readout can slip your mind if you don't use it everyday (is it left to right, or right to left that indicates pull down??)
-The hanger hook on the back is not that useful, kinda short and immobile
-Typical weird readings are occasional
Hope that was in someway helpful.
One test instrument that is 100% accurate every time is a U-tube manometer, but dealing with mercury is a pain, and reading the scale below 1 millimeter is hard.
Another test instrument that is 100% accurate every time is the Vac-U-Ator. http://web.me.com/alauciello/HVAC_To...ac-U-Ator.html
It is a wet bulb that uses methanol, as the methanol boils off, a thermometer reads the temperature, then you use a chart to compare the temp to the corresponding vacuum. Easy to use, but you have to keep buying the methanol every so often.
After that you have electronic micron gauges that may or may not be reliable, but are very easy to use.
I have an electronic but I prefer the Vac-U-Ator.
Like others I have been trying different vacuum gauges in the ye4ars I have been a tech. from the Analog by Thermal to the J/B, Supco, Y/J series and even a TigerMic. I currently use the BluVac by AccuTools; best vacuum gauge for the money I think (and not the most expensive).
BluVac Video on Youtube
see for yourself...
I have a CPS VG200 Vacuum Gauge w/Digital Display that I have used for several years now and love it.
Very reliable. http://www.google.com/products/catal...ed=0CD4Q8wIwAA