Detecting carbon monoxide in your business is almost impossible without the help of carbon monoxide monitors. CO monitors ensure the safety and quality of life are sheltered day and night, as well as property in your premises.
Carbon monoxide is colorless, odorless, and tasteless and, therefore, installing a CO detector can mean the difference between life and death within your business. However, there needs to be a sort of calibration to set off the alarm when the levels get uncomfortable and threatening.
All carbon dioxide sensors require calibration. The calibration can be accomplished by calibrating the sensor using the automatic baseline calibration or using a known gas as reference. Carbon monoxide detectors can be calibrated using some methods that have discussed below.
Calibration by use of nitrogen
One of the most accurate methods of CO sensor calibration is by exposing it to pure nitrogen. The idea is to replicate the conditions in which the sensor was originally calibrated during its manufacture. It’s worth noting that nitrogen calibration is necessary if levels of CO to be measured will range between 0-400 ppm. Calibration by use of nitrogen requires a tank of pure nitrogen, calibration software, and a sealed calibration enclosure to ensure the accuracy of the process, and consequently, it is an expensive method.
Use of fresh air
The method is a more cost effective method in comparison to nitrogen calibration. However, maximum accuracy cannot be guaranteed. The trick employs the fact that outdoor air has about 390 ppm CO concentration. Therefore, the sensor is calibrated at 400 ppm and then 400 ppm is deducted from the newly calculated counterbalance value. Calibration by use of fresh air is best suited for sensors meant to be installed in greenhouses or manufacturing settings since the sensor gets exposed to different levels of CO constantly.
Automatic baseline Calibration (ABC) calibration
This method is important to use when the sensors to be calibrated are located in offices or indoor settings of your business to necessary to measure indoor air quality (AIQ). The method is less expensive when dealing with wall-mounted units that require trained staff or removing from the wall for calibration. It utilizes the idea of using AIQ as the reference point since t at some point within each day a room has to be unoccupied, meaning the CO levels has to return to that of outdoor value of 400ppm.
The software stores the lowest reading that has been taken over several days of testing and an offset value relating to 400ppm can be calculated, which is then deducted or added to the real CO readings.
When to utilize ABC calibration
Situations that allow for recording of CO levels after every few days are best suited for use with this method. HVAC regulated conditions can as well rely on the method with great accuracy.
CO2 sensors need calibration constantly for more accurate figures to be recorded. The following gives guidelines as to how often calibration should take place.
o Personal safety – calibrate weekly or twice each month
o Manufacturing – annually or bi-annually where possible
o Indoor air quality – if ABC is used, constant calibration is not necessary
o Scientific experiments – should take place before each test is carried out