Test Gauges Explore Ashcroft test gauges and precision test gauge for your specific application. Ashcroft pressure test gauges and precision test gauges provide an accurate, dependable secondary pressure standard for the calibration of industrial and process gauges. Whether a portable digital test gauge is needed for field calibrations or an ultra-high precision test gauge is required for a calibration laboratory, you’ll find the right transfer standard in our wide selection of pressure test instruments.