Description of the INRiM measurement methodology and results in the framework of the international comparison: “CCT-K11 – Key comparison of blackbodies for infrared ear and forehead thermometers”

The Covid-19 pandemic has brought into the spotlight how unreliable body temperature measurement can be in health services and more generally around the world. The Working Group for Non-Contact Thermometry of the Consultative Committee for Thermometry (CCT-WG-NCTh) has requested to establish a Task Group for Body Temperature Measurement (TG BTM) whose objective was to establish reliable clinical thermometry on a global basis [1]. The initial focus of the TG was that of improving infrared methods for body temperature measurement. One part of the TG has decided to lead a global comparison of calibrators for infrared body temperature thermometers (especially ear and forehead thermometers) with the aim to establish a robust global metrological framework for the calibration of such devices. The objective of the comparison was to assess and verify the calibration capabilities of participating NMIs by determining the radiance temperature of one unknown temperature ear-thermometer blackbody and one unknown temperature forehead-thermometer blackbody. To reach the objective, the comparison approach was mutually between the pilot NMI supported by co-pilot NMIs from two Regional Metrology Organizations (RMOs). These are the pilot (NIM China), the APMP co-pilot (NIM China) and the EURAMET co-pilot (PTB Germany). INRiM has taken part in the key comparison in the Euramet loop. This technical report summarises the measurement procedures adopted and the results obtained.