MOLECULAR DENSITY DETERMINATION OF WATER VAPOR IN A 0.0001 TO 0.01 TORR VACUUM ENVIRONMENT BY ULTRAVIOLET ABSORPTION

摘要

A NEW SENSOR HAS BEEN DEVELOPED FOR WATER VAPOR MOLECULAR DENSITY MEASUREMENTS IN A SPACE ENVIRONMENT SIMULATION CHAMBER. ITS INTENDED USE IS TO OBTAIN MEASUREMENTS IN THE EXIT PLANES OF SUPERSONIC NOZZLES WITHOUT DISTURBING THE PLUME FLOW FIELD IN THE CHAMBER. A LABORATORY VERSION OF THE SENSOR HAS BEEN BUILT AND TESTED IN A STATIC PRESSURE ENVIRONMENT TO DETERMINE ITS SENSITIVITY. THE RESULTS SHOW THAT THE SENSOR IS EXTREMELY SENSITIVE IN DETECTING WATER VAPOR, AND THAT ITS USEFUL MEASUREMENT RANGE EXCEEDS TEN TO THE 15TH POWER MOLECULES/CC3.