The OPB350 optoelectronic fluid sensors include a self-calibration system to maintain accuracy. This makes the sensors suitable for equipment delivering IV fluids, transfusion/infusion systems, and blood plasma and urine analysis. The sensor operates with an infrared LED/phototransistor pair to determine presence or absence of fluids in a tube passing through the sensor housing. Sensors are available for designs using clear tubing with outer diameters of 1.6 mm, 3.2 mm, 4.8 mm, or 6.3mm. Operating temperature is from -40ºC to +85ºC. OPTEK TECHNOLOGY INC., Carrollton, TX. (972) 323-2200.