Pfund’s combination of the McLeod and Pirani pressure gages was studied with a number of gases. The calibration curves of pressure against galvanometer reading were found to be straight lines and, except for hydrogen, nearly interchangeable for all the gases used. By using a galvanometer of high sensitivity and introducing a compensating filament, the sensitivity of the gage was increased until a change in pressure of 1.5×10−9 mm of mercury would cause a change in deflection of 1 cm on the galvanometer scale.
Brief comments are made on the release of carbon monoxide and air from coconut charcoal and on the adsorption of air at low pressure by silica gel.
© 1924 Optical Society of AmericaFull Article | PDF Article
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