Societe Qualiflow Sa

Pascal Rudent

Alain Giani

Pierre Navratil

Andr&eacute; Boyer

Construction of a micro-thermocouple sensor designed to be incorporated in a mass flow meter for the circulation of gaseous fluids, includes of the following steps: depositing an insulating layer of several microns by electron gun on the sensor tube, then depositing the components of the thermocouple, by the electron gun, through the nickel masks, at a residual pressure lower than 10 torr, at a thickness of several thousand Angstroms, annealing of the capillary tube for one hour, then the mounting of a heating element on the capillary tube treated in this manner.

Micro-thermocouple for a mass flow meter

The sensor ( ) for a mass flow meter ( ) including a capillary tube ( ) for circulation of fluid in parallel with the principal circuit of the fluid circulation. The sensor includes heating mechanisms ( ) of the capillary tube ( ) and mechanisms for measuring the temperature ( ), upstream and downstream from this heating mechanism ( ), and separate from the heating mechanism. The mechanisms for measuring the temperature ( ) are two resistors manufactured by deposition in an external manner on the sensor tube ( ), one of them (22) upstream from the heating mechanism ( ), the other ( ) downstream from the heating mechanism. The manufacturing process includes stages of deposition by an electron gun, firstly of a layer of zirconia ( ) of several microns, on the tube ( ) made of stainless steel, then of the sensitive components ( ) and the contacts ( ) of the measurement resistors ( ), made of platinum, and defined by masks of nickel.

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Montpellier, France

Pascal Rudent