DoST’s NML ensures precise measurement standards

By The Manila Times, June 7, 2020

In the midst of the Covid-19 pandemic, every life is counting on accurate instruments and precise measurements.

In consideration of this crucial fact, the National Metrology Laboratory (NML) under the Industrial Technology Development Institute (ITDI) of the Department of Science and Technology (DoST) ensures the measurement standards in the country. It emphasizes how metrology plays a crucial role in fighting the coronavirus.

By making certain every dimension of each part conforms to specifications, medical personnel and other frontliners are assured that every ventilator valve or face shield that is 3D-printed by DoST’s Advanced Manufacturing Center (AMCen) is guaranteed of its quality and build. Ultraviolet light with a wavelength of 253.7 nm has been proven to have a germicidal effect, thus it is important to keep correct wavelength and output power in hospital rooms to ensure effectiveness.

These kits are used to test people for the coronavirus nowadays, thus the need to be calibrated to come up with accurate results every time. Measuring each sample’s volume and other measurements are important to have traceable and accurate results.

With the celebration of World Metrology Day on May 20, accurate measurement has never been more on point. The function of metrology is to calibrate devices like Infrared Thermometers (IRTs) or thermal scanners to get correct readings.

Calibrating these IRTs at this time, however, may be difficult to accomplish due to the great number of scanners that need to be calibrated. There is also the inconvenience and risk of pulling them out of service for calibration at a time when they are most needed.

An early indication of Covid-19 infection is higher than normal body temperature, thus the need for authorities to use thermal scanners. Incorrect readings could lead to a wrong diagnosis or an infected person being allowed entry hence thermal scanners need to be calibrated.

NML follows what method China used as stop-gap do-it-yourself (DIY) in checking the accuracy of IRTs instead of the usual, more rigorous calibration process performed in laboratories.

The method consists of using a comparator temperature reading of an individual using a digital or liquid-in-glass thermometer that is working and accurate and comparing the temperature reading of the same individual using an IRT.

Measurement reading of the body temperature of a normal, healthy individual using the IRT is compared with the temperature reading of an individual being screened using the same IRT. An elevated temperature would be sufficient reason for further screening by other means such as a digital or liquid-in-glass thermometer.

In this case, what is measured is not absolute temperature, which requires calibration in a laboratory, but the reading of an elevated temperature.

Thus, an IRT temperature reading of a healthy individual at 34 degrees when compared to a 36 degrees reading on an individual under screening suggests fever.

The method aims to simply determine an elevation of two degrees above the temperature reading of a normal healthy individual, which could be a sign of fever.

With this simple and easy to perform procedures, Covid-19 frontliners are assured of a fully functioning IRT without having their IRT calibrated, making them better equipped to screen for elevated temperature which is a sign of probable COVID-19 infection.