Check your tires in several places and take an average. Racing tire hardness varies in different places on the tire. This is true of almost all tires and is normal. You will get the most accurate and consistent readings by ‘rocking’ the durometer. Put it against the tire at a slight angle back, then rock it forward to upright, then forward slightly more. The pointer will rise to the true reading, then fall back.
DO NOT DROP THE UNIT. KEEP IT CLEAN AND DRY.
- If you use tire softener the rubber desolved in the liquid may get between the pin and the body, causing sticky action and incorrect readings. Clean with lacquer thinner, holding the durometer upright to avoid having any liquid run down the pin and inside unit.
- Some models - not all - have a small silver tab on the top, held in place by the knurled knob. This is to help keep the dial face from accidentally rotating in use. This feature is not on all durometer models. Changing may affect the calibration slightly. This should only be done if the durometer has been dropped and does not appear to still be in calibration. Return to factory for accurate callibration when possible.
- To check the accuracy of your durometer use the rubber test block included with some models. The hardness is shown on the card included. Keep it for future reference. Remember, temperature is important. Test at the same temp as shown. These test blocks should be replaced every 2 years. This test block is not included with all durometer models.