All Accu-Gage® 1-1/2", 2" and 2-1/2" dial tire gauges are ANSI Commerical Grade B gauges (meets ANSI B40.1 Grade B specifications), which is the best quality gauge typically used for tire pressure applications.
These tire gauges use a fully geared, solid brass precision movement with bronze bourdon tube. Unlike piston-plunger-type gauges, the bourdon tube movement is not affected by changes in temperature, humidity, altitude or air stream contaminants.
The mechanical accuracy rating is ± 2% from 25% to 75% of scale and ± 3% below 25% and above 75%.
You should select a tire gauge so the typical pressure you will be testing is in the middle of the gauge span.
Example: for a typical car tire that runs at 32 psi you would select a 60 psi tire gauge and for a light truck tire that runs at 50 psi a 100 psi tire gauge.
When selecting a tire gauge for a car, don't forget your spare! Many compact spare tires have a higher pressure requirement than a typical car tire (some as high as 80psi). Select your tire gauge(s) accordingly.
Over pressurization will damage a gauge!
Never use a gauge on a tire unless you are certain that the tire's pressure does not exceed the gauge's maximum psi reading.
Which type of chuck should I choose?
This is a matter of personal preference. All chucks work on auto tire valve stems. The swivel angle (S series and H series) and right angle chuck (H series) are great for difficult to reach valve stems.
Problem: Needle does not move when air pressure is applied or return to zero after use
Generally caused by: Over pressurization
Problem: Tire gauge does not hold pressure
Generally caused by: Dirt from the tire valve. Disassemble the gauge and clean the check assembly or return to manufacturer for cleaning.
Instructions for cleaning check assembly
To clean the check valve hold the gauge with the hose pointed up. Unscrew the hose cap that attaches the hose to the gauge body (the part with the air bleed button on it) and carefully pull the hose and cap up and out of the gauge body. Inside is a black rubber disk, a plastic disk and a conical spring. Clean the two disks and the inside of the gauge body. Also clean the end of the fitting up inside the cap on the end of the hose.
To reassemble put the spring in first, large end down, then the plastic disk and then the black rubber disk. Push/Screw the hose and cap back onto the gauge body.
To clean the check valve hold the gauge with the air chuck pointed up. Unscrew the cap that attaches to the end of the gauge body (the part with the air bleed button on it). Carefully pull the check valve up and out of the gauge body. Inside is a black rubber disk, a plastic disk and a conical spring. Clean the two disks, the inside of the gauge body and the check valve.
To reassemble put the spring in first, large end down, then the plastic disk and then the black rubber disk. Push the check valve into the gauge body and screw the cap back onto the gauge body.