The TruCell2 cell density loop is a near-infrared light absorption sensor that comprises an optical probe, selectable from a variety of configurations, a cable, and a transmitter.

The optical probe includes the main shaft, the sensor head, and the electrical connector that is connected to the transmitter using a cable (6 ft [1.83 m] or 10 ft long [3.05 m]). For a given transmitter, the sensor probe can be replaced. The sensor probe can be separated from the cable and transmitter for sterilization.

The transmitter integrates the signal processing, power conversion, 4-20 mA output signal generation, and user interface functions in one package.