RAMAN HYDROGEN SENSOR (RHS) FOR PROCESS AIR DUCTING

A HIGHLY RESPONSIVE GASEOUS HYDROGEN SENSOR IS REQUIRED FOR OPERATION IN PROCESS AIR DUCTING AT AEDC, TO INSURE SAFETY IN THE TESTING OF AIRCRAFT ENGINES. FAST RESPONSE, HIGH SENSITIVITY, AND THE ABILITY TO HANDLE WIDE RANGES OF SAMPLE PRESSURE AND TEMPERATURE ARE REQUIRED. SPECTRAL SCIENCES, INC. (SSI) PROPOSES TO DEVELOP A LASER RAMAN HYDROGEN SENSOR (RHS) FOR PROCESS AIR DUCTING. RHS WILL REPRESENT A FURTHER EXTENSION OF NEW, PATENTED TECHNOLOGY DEVELOPED BY SSI FOR NASA'S SPACES HUTTLE PROGRAM. ADVANTAGES OF RAMAN DETECTION INCLUD LINEARITY, GOOD SELECTIVITY, AND INSENSITIVITY TO TEMPERATURE, FLOW RATE, AND BACKGROUND GAS COMPOSITION. THE GOAL IN THE RHS PHASE I PROGRAM IS TO DEMONSTRATE THE FEASIBILITY OF THIS TECHNOLOGYFOR AEDC'S APPLICATION UNDER SIMULATED SAMPLE CONDITIONS AND WITH THE REQUIRED TIME RESPONSE. THE RHS OPERATES BY PASSING LASER LIGHT THROUGH A SELECTIVE FILTER, AND CONVERTING THE OPTICAL SIGNAL INTO THE DESIRED OUTPUT SIGNAL. THE DUCT GAS IS SAMPLED THROUGH A SHORT INTAKE PIPE. FAST SAMPLE TRANSPORT AND SENSOR ELECTRONICS WILL ENSURE A TOTAL RESPONSE TIME OF UNDER 0.25 SEC.