Gas density sensor for real-time monitoring in a high pressure reactor

Description

We present the design of a gas density sensor based on quartz crystal resonators (QCR) which are in contact with the surrounding gas at high pressure (2.5 * 106 Pa) and high temperature (340 K). The resonance frequency of QCRs is generally shifted in dependence on the density and the viscosity of the surrounding medium (e.g. [1] for shear mode resonators). Tuning fork resonators have successfully been used in gas density measurements [2]. In our contribution tuning fork (TF) and shear-mode (SM) devices are compared with respect to their sensitivity to gas density. It was confirmed, that TF resonators are mainly sensitive to density, whereas SM resonators are more suitable for viscosity measurement. In high pressure gases, an additional pressure dependent frequency shift has to be considered for SM resonators. With a tuning fork resonator, an accuracy of 0.015 kg/m3 was achieved with a first prototype.

Period	07 Sept 2009
Event title	Eurosensors 2009
Event type	Conference
Location	SwitzerlandShow on map