LONGACRE LIQUID FILLED TIRE GAUGE - BALL CHUCK

All pressure gauges - liquid filled and regular - need to be vented to the outside to read accurately. If not vented, as the surrounding temperature changes, they will build up pressure inside and affect the accuracy - by as much as 2-3 psi! But if a liquid filled gauge is vented it will leak on your hands and in your tool box. Some manufacturers are aware of this and don't vent the gauge. You then have to deal with the variation in accuracy.

Longacre's Liquid Filled Tire Gauge has a specially designed pressure equalizer valve on the top of the gauge. Before you use the gauge just loosen the knob on top of the gauge 1/4 turn, then hand retighten. Instantly any temperature-caused pressure difference will be eliminated and you will be guaranteed the most accurate readings possible.