Evaluation of laboratory accuracy of forehead radiation thermometers using blackbody sources for tympanic thermometers defined by international standards with adaptors.

In view of the gaps between the current clinical thermometer standards and the commercially available products, in particular the introduction of forehead radiation thermometers into the market, ISO initiated a review on standard for clinical thermometers. The original clinical thermometer standard includes requirements for evaluating tympanic (ear) thermometers using identified reference blackbody sources. However, one of the challenges in reviewing the standard is to understand if the reference blackbody sources identified for ear thermometers are still usable for evaluating the laboratory accuracy of forehead thermometers. In order to answer this challenge, four brand new forehead thermometers from two different manufacturers are evaluated at NMC. Two reference blackbody sources, one JIS standard source with very small opening and one NMC source with larger opening, are used for the evaluation. In order to use JIS standard source, two types of adaptors, one supplied by one of the manufactures, one 3D printed, are evaluated. The measurement results together with their measurement uncertainties are presented and analysed. Suitable adaptors are identified and recommended.