Capacitive pressure sensor with linear response - contains piston comprising mass of mercury forming capacitor with metallic deposit on tube

• Main Author: JEAN-MARC BOISGONTIER ET MAURICE LA BALME
• Format: Patent
• Language: English; French
• Published: 04.12.1981
• Subjects: MEASURING; MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER,MECHANICAL EFFICIENCY, OR FLUID PRESSURE; PHYSICS; TESTING

The device has sealed metallic envelope (1) with an inlet to which the pressure being measured is applied. A ceramic tube (6) passes through the wall which forms two separate compartments. The tube contains a mass of mercury contained by two washers to form a capacitor with a metallic deposit on the tube. The pressure in the outer compartment moves the mass of mercury against the action of a spring attached to a rod which is fixed to the base of the tube. The change in capacitance is detected by connections to the rod and the deposit. The device can be used as an altimeter and has a linear response which is independent of axial acceleration. CAPTEUR CAPACITIF DE PRESSION COMPRENANT DEUX ARMATURES SEPAREES PAR UN DIELECTRIQUE, DONT L'UNE AU MOINS EST DEFORMABLE SOUS L'EFFET DE LA PRESSION. LA VARIATION DE CAPACITE EST MESUREE PAR UN CIRCUIT ELECTRIQUE.LE DIELECTRIQUE EST UN TUBE 6 EN CERAMIQUE PORTANT UN DEPOT METALLIQUE 7 FORMANT ARMATURE EXTERNE ET RELIE A UNE CONNEXION 15. L'ARMATURE INTERNE EST FORMEE PAR UNE MASSE DE MERCURE 8 RETENUE ENTRE DEUX PLAQUES 9, 11 COULISSANT DANS LE TUBE 6. UN RESSORT ANTAGONISTE 12 SERT DE CONDUCTEUR ENTRE LE MERCURE ET UNE CONNEXION 14. LA PRESSION A MESURER EST ADMISE DANS LE COMPARTIMENT 3 ET FAIT DEPLACER LE MERCURE POUR MODIFIER LA CAPACITE.APPLICATION A TOUTE MESURE DE PRESSION A DISTANCE, NOTAMMENT DE LA PRESSION DES PNEUMATIQUES DE ROUES.