M. F. Pool

A bidirectional recording gasometer with solid state sensing element

Abstract A bidirectional recording gasometer with solid state sensing element has been developed. The design of the instrument and the materials used for its construction permit a wide range of applications in which volume changes occur. Volumetric changes can be monitored independently of barometric changes, air different temperatures and under partial vacuum or pressure. The instrument is calibrated to read directly in volume units, which are recorded on a linear scale versus time. Response to pressure changes is relatively best and high sensitivities in the order of 10 −4 of full scale have been observed. Samples can be introduced or withdrawn during operation through a septum-type injection port or initially placed directly into the sample vessel. Use of a solid state sensing element eliminates a barometric fluid and thus increases sensitivity as well as reliability and ease of handling of the gasometer. The instrument can be used on a standby basis since it is of constant-pressure design and adapts to large changes in sample sizes.