Improved dial type comparator
Ltd. A. C. Wickman · Journal of Scientific Instruments · 1942
NEW INS'I'KUMENTS, MATERIALS AND 'K"heated for a longer period than I O min.at a few degrees less than zoo' C , the colour change may take placc at this slightly IN this precision thermostat control the position of the the right-hand limh, and the mercury level can also be adjusted hy meanS of a similar head on the other limb.I t is