Electronic Fluid Sensors

One specific type of IR sensor assembly is used as a noncontact fluid sensor in a range of applications, from monitoring intravenous fluids in medical equipment and checking toner fluid in printing to various other uses involving both water and petrochemicals. These sensors combine an infra-red light-emitting diode with a phototransistor receiver, separated by a circular orifice that accepts clear tubing. Clear liquid in the tube causes the phototransistor to sink the maximum current, whereas dark liquid in the tube causes it to sink the minimum current. And if bubbles are present in the flow, the output will fluctuate between the two levels. With suitable reference circuitry, these sensors can perform a number of roles and recognise various states of fluid presence within the tube. Multiple output states such as "fluid present", "no fluid present" and "no tube present" can be recognised. Please contact Pacer International for more information on Electronic Fluid Sensors.