Pressure Sensor

Abstract

A pressure sensor includes a diaphragm having a displaceable elastic inner portion, wherein the inner portion displaces in response to a pressure difference between first and second sides of the diaphragm. A radiation source may be configured to transmit first and second beams of radiation. A light receiver may be configured to receive the first beam of radiation directly from the radiation source and the second beam of radiation after it reflects from the first side of the diaphragm. A control system may be coupled to the radiation source and light receiver and adapted to determine the pressure difference from the displacement of the diaphragm.

1 . A pressure sensor, comprising: 
 a diaphragm having a displaceable elastic inner portion, wherein the inner portion displaces in response to a pressure difference between first and second sides of the diaphragm;    a radiation source configured to transmit first and second beams of radiation;    a light receiver configured to receive the first beam of radiation directly from the radiation source and the second beam of radiation after the second beam of radiation reflects from the first side of the diaphragm; and    a control system coupled to the radiation source and light receiver and adapted to determine the pressure difference from the displacement of the diaphragm.    
   
   
       2 . The pressure sensor of  claim 1 , wherein the diaphragm includes a diffusely reflecting metal film.  
   
   
       3 . The pressure sensor of  claim 1 , wherein the pressure sensor to measure at least one of gauge, absolute, or differential pressure.  
   
   
       4 . The pressure sensor of  claim 1 , further comprising an optically reflective coating on the first side of the diaphragm.  
   
   
       5 . The pressure sensor of  claim 1 , wherein the control system calculates the displacement of the diaphragm from an interference pattern generated from the first and second beams of radiation.  
   
   
       6 . The pressure sensor of  claim 5 , wherein the radiation source comprises a transmitting fiber having an output coupled to a diffraction device that separates a source light into the first and second beams of radiation, wherein changes in the diaphragm displacement cause the interference pattern to include intensity modulated light, wherein the control system calculates the diaphragm displacement from the intensity modulated light.  
   
   
       7 . The pressure sensor of  claim 1 , wherein the elastic inner portion comprises a polyimide film.  
   
   
       8 . The pressure sensor of  claim 1 , wherein the elastic inner portion comprises a thin polyester film.  
   
   
       9 . The pressure sensor according to  claim 1 , wherein the elastic inner portion comprises rubber.