Abstract: A cell block for housing a sensor cell within a gas analyzer is mounted on the front panel of the analyzer, holding the sensor within a horizontal plane. The cell block is made of inexpensive and non-permeable material such as aluminum which is brazed and anodized. Entry and exit of sample gas is unique as is sample gas exposure to the sensor. Dead space is minimized and response time is improved. An insulated thermister in the cell block maintains accuracy over a wide range of temperatures. The device is RFI and EMI protected.