How to calibrate the YONG HENG 300bar auto-shut-off gauge?

[grouch-o]

Hello everybody,
in my compressor the gauge does not return to zero when there is no pressure on the line. So it is a bit off (it shows 80bar, when there is no pressure), which of course leads to an early shut off, below 300bar. (which i can see from several tank as well as gun gauges.)
since i would like to fill my tanks to 300bar, but do not want to disable the auto-shut-off function, i was wondering if it is possible to calibrate the gauge of the YONG HENG.
there are two phillips screws on the underside. i have not taken it off, because i do not want to compromise the seal.

if anybody has a clue on this matter, i would appreciate any helpful hints.

thank you.

 

[WorriedMan]

Consider replacing gauge, they don't last long due to vibration anyways. Here's pic of my three-year-old leaker, replacements aren't that expensive on eBay. Never used Set Pressure function so just replaced with liquid-filled gauge borrowed from Chinese HPA handpump. WM

 

[Gerry52]

I would NOT try to calibrate it. The 2 screws on back are what holds gauge calibration plate (dial face) in place. MOST of the gauges on our "asian" compressors ARE NOT pieces of precision equipment, more like a "ball park estimate" piece of equipment. I'd replace it rather than try to fix. Also, just because it reads 80 bar when not under pressure don't assume that it's the same over the total range of its operation. Bottom line, it's squirrely, I'd replace it.

 

[WorriedMan]

A year ago, when my original gauge went bad, eBay replacements could be had for slightly less than $20, now they're slightly less than $30. Non-adjustable, liquid-filled will handle vibrations better if you can live without automatic stop. WM

 

[Scotty1]

My auto shutoff gauge was pretty quickly shaken to death. I just did not use that gauge, and relied on the bottle gauges.

 

[grouch-o]

thank you all for your quick responses. they are helpful to me.

 

[bigHUN]

I removed that one and installed 3 larger OD gauges between the compressor cylinder and the tanks. Cross checking works more reliable.
And btw when the compressor is running, I am always in close proximity just in case... never leave the compressor running alone.