Abstract

Aims: To encountered in using thermopile device (thermocouple) as densitometer for measuring optical
density for X–radiation film which is used in dental medicine. Materials and methods: Americium–
241(Am–241) 59.5keV was used to expose a number of dental X–ray films for different times to
end with a variety of optical densities on them. Results: A comparison of the optical density readings
between the densitometer and thermopile was made. Conclusions: The thermopile was capable to
measure the optical density of any transparent polymer material while the densitometer can measure
the optical density of the X–ray film only.