British physiologist J S Haldane (1860-1936), developed this device while studying the composition of air in work places. In 1960, E J M Campbell modified it for hospital use where low cost and convenience were most needed. This example was used at St Mary's Hospital in Luton in their chest and respiratory clinics to monitor the percentage of carbon dioxide in expired air.

Samples of air from patients are collected in a gas bag. Using a syringe, small amounts are injected into the glassware. Potassium hydroxide absorbs carbon dioxide and as the mercury levelling bulb moves, a reading can be taken.