... 3)Measuring Speed:1.5cm/sec 4)Stainless Steel 150mm Digital Vernier Caliper 1. Has finely honed jaws for exacting inside, outside and ... and replace after 30 seconds to reset systemAccuracy less than +/-0.001mmDirt in the sensorRemove slider cover and its assembly, clean ... zero, close external measuring jaws, then press "ZERO" button. 150mm Digital Vernier Caliper