Kebs wants all thermal guns re-calibrated

The standards body has asked owners of thermal guns (non-contact infrared thermometer) to re-calibrate them to improve the accuracy of their readings.

The gadgets are used to check temperatures in public places and hospitals in the fight against Covid-19. Kenya Bureau of Standards (Kebs) said the re-calibration ought to take into account any ‘drift’ or low change in the response of a gauge - in the course of their use.

This has been occasioned by instances of faulty readings of these devices which are now mandatory in all public spaces for screening possible Covid-19 cases.

Drifting on measurement gadgets occurs as part of the ageing process of some of the components of the device or changes in the environment among them humidity or temperatures. Any temperature above 37.5 degrees Celsius is considered above normal, hence a suspected Covid-19 case.

Erratic measurements

Josephat Bangi, who heads the metrology department at the Kenya Bureau of Standards, said one sign that the thermal gun needs to be re-calibrated is when it becomes ‘erratic’ when giving readings.

“People have their temperature taken and it turns out to be not as expected or not specific,” he explained. “When you notice your thermal gun is erratic, and it gives erratic measurements, then it could be time for it to be re-calibrated.”

Bangi says while some thermal guns have an upper limit reading of 42 degrees Celsius, some can go to 50. “Some are also affected by magnetism,” he said.

Sometimes, he noted, depends on the manufacturer’s instructions. “What is recommended depends on the frequency of use. There are places where thermo guns measure small populations, maybe you have five people in your institution while there are other organisations where the number of people being measured in a day is so huge and the thermo gun is so busy the whole day,” he explained.

Some manufacturers would recommend after a year but there are no uniform timelines as this depends on the frequency of use.