Hamilton has developed the VisiPro DO Ex, which it claims is the first optical sensor to be approved for measuring dissolved oxygen in an explosive environment.
Having received ATEX approval, the device can be used in hazardous areas with potentially explosive mixtures of air and combustible gases or chemical liquids.
Hamilton, which has manufacturing facilities in Reno, Nevada in the US and Bonaduz in Switzerland, says compared with conventional electrochemical (amperometric) sensors, the VisiPro DO Ex works independently of the flow rate and – without polarisation time – is particularly quick to use. The optical measuring technology also improves the measurement performance and simplifies maintenance.
The device is approved for use in a temperature range between –10°C and 140°C and at pressures of up to 12 bar. With its integrated transmitter, the sensor allows direct communication to the process control system via a 4–20mA two-wire standard signal or a digital HART signal.
All relevant sensor data, including calibration and diagnostic information, are stored in the sensor head, which facilitates both calibration and maintenance. Additional wireless data transmission from the sensor to the computer greatly simplifies calibration in the laboratory, configuration and maintenance. The sensor is highly resistant to many chemicals and is also not sensitive to pressure shocks.
