Citicel Sensors and the GasAlertMicroClip XL

If you are trying to replace one of the sensors in your MicroClip XL you may notice that you see markings on the sensor such as Citicel or City Technology, or MICROceL.  This is the name of manufacturer of the sensor, City Technology, and commonly referred to as City Tech.  MICROceL and Citicel are the names of the models of sensors. 

City Technology is a UK company that has been producing sensors for many years and have been pioneers in the gas sensor world.  In fact a large majority of the instruments on the market today use City Technology sensors. 

City Technology was acquired several years ago by Honeywell Analytics and is now part of the Honeywell family.  This is important to realize because the Gas Alert Micro Clip XL is completely manufactured by Honeywell, both the instrument and the sensors.

City Technology has devised a color scheme to easily differentiate the MICROCel sensors.  Red is Carbon Monoxide, blue is Hydrogen Sulfide, and dark gray is LEL.  This is helpful for identifying the sensors at a glance, and to prevent sensors from being installed into the wrong channels.   In addition you will notice that the sensor says MICROceL CF for the carbon monoxide sensor, and MICROceL HS for the hydrogen sulfide sensor.   

MICROceL sensors are always installed with the white disc facing upward.  This white disc is a filter which covers the sensor opening and therefore must be installed facing upward so that the gas will enter the sensor chamber.  The body of the MICROceL is constructed in such a way that it will only fit into the GasAlertMicroClip XL in the proper direction.  The sensor should slide into the holder easily.  If you encounter resistance stop immediately and make sure that it is facing the correct direction. 

Part number for the H2S sensor is SR-H-MC and the CO sensor is SR-M-MC.  The LEL sensor is SR-WP75C.

The oxygen (O2) Citicel sensor will be blue and have markings that say 4OXV Citicel.  There is also a chance that the sensor may be purple and black in color.  This is a slightly different and older version of the sensor.  Both are compatible with the GasAlertMicroClip XL, however new instruments are shipping with the new and improved blue version.    Even though both are compatible it is recommended to only use the newer blue version (SR-X2V).  The reason is that the purple version (SR-X10-C1) does not contain a pressure relief port.  This allows the sensor to expand and contact in different temperatures.  Since the SR-X10-C1 lacked this feature the body of the sensor would often crack due to temperature changes.  Installation is straightforward, simply plug it into the sensor port since it will only plug in one way.

After installation of a new sensor the instrument must be re-calibrated.