I have a Pressure Trace with strain gauge.the first bought in 2005,direct wired, and failed this year.The second, wireless Blue Tooth and just installed.I reported results in 2005 and received comments about calibration and tried to explain how that is done with a strain gauge.Some just cannot understand,but if you wish,go to the Pressure Trace site and read or have someone read it to you. -snip-
It's really quite simple. Here is a quotation from the PressureTrace web site;
"PressureTrace will generate PSI estimates without calibrating the system to a factory load!
Using factory ammo or a load reference with known pressure to verify results is always recommended but we recognize each chamber will produce different pressures and wildcatters may have nothing for comparison. PressureTrace uses both thick and thin wall open vessel algorithms to provide reasonably accurate pressure estimates from barrel, chamber and brass dimensions. Unlike other products PressureTrace does not require a large correction "fudge" factor for pressure held by the brass but the system can still be calibrated to match other pressure systems. For safety, NEVER exceed the loads in a reputable load manual.
Note: If a barrel is not cylindrical at the chamber (where the gage is glued) the system MUST be calibrated against a load of known pressure. This is particularly true of double barrel shotguns with a strong flare near the locking mechanism, octagonal barrels, etc."
Your strain gauge is not calibrated and produces only SWAG estimates of the pressures inside the barrel to which it is wired. RSI admits as much; '...reasonably accurate pressure estimates...'.
None of this is necessarily bad, so long as we don't start treating SWAGs as if they were accurate measurements.
If you find any of this difficult to understand, perhaps it will help if you 'have someone read it to you.'
