A tandem diameter gauge for use in Antarctic ice hole

摘要

A diameter gauge which has two diameter calipers 0.53m apart was developed for the Japanese Antarctic Research Expedition. Each caliper has three contact wheels which are spring-loaded through the supporting rods. The use of two calipers makes a better alignment between the axes of the hole and the gauge. Diameters in the range from 90 to 190mm can be measured with an accuracy of ±1.5mm.