Test the accuracy of tire pressure gauges and tire inflation gauges. Designed to higher accuracy standards than typical tire gauges, these calibrators are not meant to be used to regularly check tire pressure directly. Instead, they serve as an objective reference to eliminate inaccuracies and discrepancies between your gauges. To use, check tire pressure first using the calibrator and then again with your tire pressure gauge. Make calibration adjustments to your gauge until its reading matches the reading on the calibrator.