Crius 3200 dissolved oxygen monitor

The Crius 3200 dissolved oxygen monitor offers an automatic in-situ calibration check as an option, making it able to save customers money by checking its calibration at user-defined time intervals.

The sensing element (lumiphore) is activated, or excited, when illuminated with a blue light. When activated, the sensor emits red light in an intensity that is inversely proportional to the amount of oxygen present in the water. The time delay between the peak emission of blue light and peak response of fluoresced red light is inversely proportional to the amount of oxygen present. The resulting phase shift between the incident blue light and the fluoresced red light is converted by the electronics into a ppm or mg/L reading of dissolved oxygen. The advantages of this technology are that it is more stable than traditional electrochemical devices and far more resistant to abrasion.

The Crius 3200 offers a number of communication protocols including Modbus, TCP/IP, USB, RS485 and TTL, as well as relay and 4-20 mA outputs. Dual and triple validation options and a PID control function are also available.

The sensor has a range of 0-20 mg/L or 0-450% saturation, and a resolution of 0.01 mg/L. Precision is ±0.1 mg/L from 0-8 mg/L and ±0.2mg/L from 8-20 mg/L, with stability better than 1% per month (without calibration). The operating temperature range is up to 50 °C, and the sensor can be operated in pH ranges from 2 to 10 and salinity up to 42 ppt.