The OT-3 instrument is designed for the measurement of natural gas oxygen. It monitors the oxygen content in various types of gases at the PPM level. Two oxygen analysis ranges come with the transmitter: 0 to 1,000-PPM and 0 to 100-PPM. When it is used in conjunction with a non-incendive power source, the instrument is acceptable for operation in Groups D, C, and B hazardous environments, as specified in Class I, Division 2. The ideal power source is the Elsag Baily TotalFlow 6713 FCU. The system can operate as low as 9-VDC, and is unaffected by HC’s, SO2, CO, and other reducing agents. The amount of oxygen in a sample is translated by Teledyne’s Micro-fuel cell oxygen sensor into an electrical current. Since the cell is sealed, there are no electrodes to clean or electrolytes to charge. This allows for easy maintenance of the sensor.