NEW SENSOR FOR MEASUREMENT OF AIR MOVEMENT

THIS PROPOSAL IS PREPARED IN DIRECT RESPONSE TO THE NRC'S SOLICITATION FOR AN IMPROVED DEVICE TO MEASURE AIR MOVEMENT FOR PERSONNEL RADIATION PROTECTION AND HEALTH PHYSICS APPLICATIONS IN NUCLEAR FACILITIES. THE PURPOSE OF THE NEW DEVICE IS TO PROPERLY LOCATE AIR SAMPLERS SO THAT THE AIR SAMPLED IS REPRESENTATIVE OF THE AIR INHALED BY WORKERS. ALTHOUGH AIR FLOW RATE SENSORS SUCH AS ANEMOMETERS ARE COMMERCIALLY AVAILABLE, THEY ARE NOT SENSITIVE AND RELIABLE ENOUGH FOR MONITORING OF LOW FLOW RATES. THEREFORE, THIS PROPOSAL OFFERS RESEARCH TO DEVELOP A NEW AIR FLOW SENSOR USING A CONVENTIONAL THERMOCOUPLE AS THE BASIC ELEMENT. THIS SENSOR TAKES ADVANTAGE OF THE SENSITIVITY OF DYNAMIC RESPONSE TIME OF THERMOCOUPLES TO AMBIENT AIR FLOW. THE RESPONSE TIME IS MEASURED AT SEVERAL FLOW RATES OF AIR AND A CORRELATION IS ESTABLISHED BETWEEN THE RESPONSE TIME AND FLOW RATE. THIS CORRELATION IS THEN USED TO DETERMINE LOW FLOW RATES BY MEASURING THE RESPONSE TIME OF THE THERMOCOUPLE USING THE LOOP CURRENT STEP RESPONSE (LCSR) METHOD. THE LCSR METHOD HAS ALREADY BEEN DEVELOPED AND IS IN USE FOR IN-SITU RESPONSE TIME TESTING OF TEMPERATURE SENSORS AS INSTALLED IN OPERATING NUCLEAR PLANTS.