Rationale

This ballot is proposed to modify section 6.3 Temperature Measuring Device and specifically 6.3.3 to allow the use of properly verified electronic measuring systems as a referee in cases of dispute. The use of liquid-in-glass Hg thermometers, as elucidated in Section 1.5, has been discouraged for some time and is subject to availability due to the nature of its toxicity. Electronic temperature measuring systems used in automated apparatus, when properly verified, have shown to provide results in alignment with the Hg thermometers in precision studies and are the preferred apparatus for the laboratories for years. Check standards for D86 have been developed which have shown similar performance to the Hg thermometer and are described in an Annex. The verification procedures for the electronic temperature measuring systems now prescribe use of these check standards in the verification of their dynamic performance. Properly verified electronic temperature measuring systems should be considered the preferred technique as the precision for the automated apparatus has been updated relatively recently, while the precision for Hg thermometers have remained untouched for decades.