Dubai, UAE: The issue of carbon monoxide (CO) poisoning in underground car parks is a serious cause of concern due to the life threat that it poses. Despite the high risk, there are those who do not install the system in order to cut down expenditure. Installing CO sensors at the right spots can go a long way in tackling the issue. Syed Taqi Hussain, Managing Partner of Green Tech, however, highlights one major challenge of CO sensors.

Hussain emphasises on the lack of maintenance of sensors and the need for them to be periodically calibrated after installation. “Since the sensor element is electrochemical, there is constant chemical reaction in the sensor and, therefore, after a few months of installing a sensor, the sensor element loses its efficiency and stability,” he explains. “That is, if the CO level is high, it will still show the reading as low. This means that if the set-point is set as 20 ppm, the fans will be switched on, when the actual is above 20 ppm. In fact, it could be anything from above 20 to 300 ppm, based on the chemical reaction of the sensor element.”

The solution to this problem is rather a simple one – recalibrate the sensor. However, it is not stringently followed. Hussain says that ideally, the CO sensors must be recalibrated at least once a year, but preferably every six months “in order to ensure accurate and proper operation”, and avoid any potentially detrimental situation that may occur during high CO concentration. “The duration of the recalibration process,” he says, “will depend upon the amount of target gas the sensor is exposed to, or the extent of deterioration of the sensor, whereby one sensor can have its calibration re-established quicker than another, depending on the installation location.”

In addition to reducing the threat of CO poisoning, regular recaliberation offers energy-saving, and prevents under-performance, adds Hussain. “Some sensors show the reading as high, irrespective of the reading being low and, consequently, all the exhaust fans in the basement get switched on to high speed. However, the calibration procedure will fix the sensors and make them work as per their requirement.”

Reiterating his point, Hussain says that installing CO detectors and maintaining them can go a long way in preventing any life-threatening situations.