One of the largest costs of monitoring gas levels is the ongoing cost of sensor calibration. The TR250Z Oxygen Sensor and O2/CO2 Combination Sensor are both designed to be calibrated in situ with the push of a button using normal room air. This simplified process enables calibration to be performed quickly and at regular intervals by maintenance personnel instead of outsourcing the task. The O2 sensors are used in environments where oxygen depletion may occur, such as liquid-nitrogen storage rooms, vacuum test chambers and any workplace where pressurized gases can displace O2. The combined O2/CO2 sensor is suited for modified atmosphere-packaging operations for packaging and transport of meats, poultry, fruit, vegetables and other goods. — CO2Meter.com, Ormond, Fla.