Product Description Replacement Infrared Carbon Dioxide/Methane LEL sensor for the Ventis® Pro. The CO2/CH4 sensor is a single sensor that can detect both CO2 and CH4. The CO2/CH4 sensor has a CO2 measuring range of 0-5% by volume with a .01% by volume resolution. The CH4 can be set for a measuring range of 0-5% by volume with a .01% by volume resolution, or a 0-100% by volume measuring range with a .1% by volume resolution. If the CH4 is set for a 0-5% by volume measuring range, the calibration gas concentration is 2.5% by volume methane. If the CH4 is set for a 0-100% by volume measuring range, the calibration gas concentration is 99% by volume methane. If this sensor is set for the 0-100% by volume measuring range and calibrated with 99% by volume methane, the calibrations must be done by hand as the Docking Stations are not intrinsically safe. This 4 series senor is only available for the Ventis Pro 5, and must be installed in location 2. (This sensor will not fit or work with Ventis MX4 Series Gas Monitors)Has your CO2/CH4 sensor failed or has a measuring range that's all over the place? It might be time to replace it. Repair your Industrial Scientific Ventis Pro Multi-Gas monitor by purchasing a new genuine Industrial Scientific (CO2/CH4) Carbon Dioxide / Methane Infrared Sensor.Need some DIY help changing a sensor or just some friendly technical help with repairing your instrument? Call customer service at 1-800-949-7233.