The ST420 is an analog-output shaft speed sensor. It detects magnetic pulses from a rotating shaft-mounted magnetic pulser target (disc or wrap) and outputs a smooth continuous 4-20mA analog signal in direct proportion to the pulse frequency (rotating shaft speed). The ST420 combines a magnetic pulse detector, signal processing and 2-wire loop-powered 4-20mA circuitry into a stainless-steel M18x1 sensor housing.
