Operation In Gas

Design and Operation In practice, in most cases, direct measurement of large and medium-sized quantities of mass flow of air with relatively low accuracy is performed by mechanical means (Flow from the impeller). They are characterized by low long-term stability of parameters, the inability to measure very small currents and the relatively large size devices, measuring instruments. Much better results give methods indirect measurement of the flow, based on recalculations of signals with high precision temperature sensors or absolute (differential) pressure, in some way included in the gas line. It is an indirect method for measuring mass flow of gas lies at the heart of all the sensors Honeywell. Mastery of technology development and manufacturing of mems devices has allowed the company to create a unique mikromostovoy measuring element, Honeywell provides flow fast response time, high sensitivity, repeatability and very low hysteresis. The chip includes a heating element and two are located on its both parties Ny thermosensitive sensor. These components are made of thin platinum films deposited between two layers of silicon nitride. By anisotropic etching of silicon nitride formed on the underside of the two bridges. Each bridge consists of one temperature sensor, and half the heater. And each bridge can be defined as the input and output for the gas flow. The principle of this system is based on the mechanism of transfer of gas flow relative amount of heat over the surface of the meter with the further registration of temperature difference of temperature sensors of the bridge at the entrance and exit.