Are there any pressure switches available with adjustable hysteresis?

I'm using a pneumatic nail gun to build by timber frame kit for the house extension and the damn compressor cycles between an indicated 100psi and 135psi. I think the pressure gauge is a bit optimistic as the gun will not operate at the indicated 100psi where it should - anyhow.

If I increase the pressure above 135psi the safety valve blows and I am understandably reluctant to alter this!

So I need a pressure switch where I can adjust the difference between on and off to arounf 15 to 20 psi.

Any ideas? The blessed kit is nearly finished now but I'd like to make it easier for next time

The compressor is an old Tiger 8/25 airmaster.

Cheers!

We use switches that have an on and off set point so you can have whatever differential you want. I'l try to find a linky.

These look like the ones we use but it's hard to see from the piccies if there is a screwdriver hole for the on and one for the off!
http://www.machinemart.co.uk/shop/range/guid/E9235C6C-0986-42ED-9C3F-7BD97C90F624

I'll have a look at the gear we have at work on Thursday.

[Edited on 11/10/11 by owelly]

Ta much appreciated