Originally Posted by Blaster 84
I took my two gauges to three different tire shops and asked them which one is correct. The first shop said they have no way of knowing and if we compared with their technicians they would all be different. The second shop said they didn't trust digital gauges but also commented that some times the pencil type gauge would drag. The third shop noted that my pencil type gauge had a 120 lb. max reading and he felt the gauge would not be accurate at the lower readings. He tested both gauges and said the digital gauge is definitely was the most accurate.
I observed that during this testing the readings were getting closer to each other and sometimes read the same. I believe the pencil type gauge did become inaccurate do to lack of use. The more I used it the more accurate it became. In the future I'll rely on my digital gauge.
I commend you for all the effort and energy you have put into trying to find the most accurate tire pressure gauge.
The only other input I have, other than what I posted earlier in this thread, comes from my experience as a FAA Airworthiness Inspector assigned to a major U.S. airline. That being that the FAA requires major airlines is have a procedure to ensure that any equipment used to determine the final airworthiness status of a component is periodically calibrated to determine it is performing its function correctly. Such equipment includes VOM, electrical measuring devices, torque wrenches etc. Also included are tire pressure gauges because airlines usually check tire pressures on overnight maintenance checks.
These gauges, as you might suspect, are not the usual ones you can buy at your local auto supply store - they are very rugged and I never saw any pencil type gauges used, only the analog type. I can't comment on the digital type because I never saw those being used.
Bottom line - go with the digital or analog gauge IMO.