OPTEK Technology (Carrollton, TX) offers the OCB350 Series fluid sensor that features automatic calibration circuitry. It is available with multiple output states for medical applications. Designers can initiate the calibration procedure at any time by grounding the J1-pin-4, which allows the device to be remotely calibrated and then mounted in the equipment. The housing includes an opening that accommodates clear tubing with outer diameters of 0.0625”, 0.125”, or 0.1875”. The infrared LED features a forward DC current of 50 mA with a peak current of 1.0 A. Reverse DC voltage is 2.0 V and power dissipation is 100 mW. The output photo-transistor features a maximum collector-emitter volage of 24V or 30V, with collector DC current of 50 mA and power dissipation to 100 mW. Operating temperature ranges from -40 °C to 85 °C.