THE DEVELOPMENT OF A HIGH-SPEED PORTABLE APPARATUS FOR THE IN-FIELD QUANTITATIVE ANALYSIS OF ASBESTOS

A PORTABLE INSTRUMENT, BASED ON THE PRINCIPLES OF X-RAY DIFFRACTION, IS PROPOSED WHICH WILL ALLOW QUANTITATIVE DETERMINATION OF THE PRESENCE OF ASBESTOS IN MATERIALS OF CONSTRUCTION. PRELIMINARY TESTS SHOW THAT A RESOLUTION OF A FEW WEIGHT PERCENT ASBESTOS CAN BE EASILY MEASURED. ANALYSISOF THE SYSTEM X-RAY PHYSICS INDICATE A LOWER LEVEL OF DETECTABILITY OF A FEW TENTHS OF A PERCENT SHOULD BE ACHIEVABLE. THESE LEVELS ARE WELL BELOW THOSE REQUIRED BY CURRENT REGULATIONS. THE ADVANTAGES OF THE PROPOSED INSTRUMENTS ARE (1) IT IS PROTABLE, THUS ALLOWING MEASUREMENTS IN THE FIELD; (2) IT IS FAST, WITH MEASUREMENT TIMES OF FEW MINUTES; (3) IT IS FULLY ATOMATIC AND COMPUTER -COMTROLLED; (4) SAMPLE PREPARATION IS QUITE SIMPLE, IN- INVOLVING ONLY GRINDING AN APPROPRIATE POWDER AND PRESSING IT INTO A DISK; AND (5) IT IS NOT AS LABOR INTENSIVE AS COMPETITIVE METHODS. THESE ADVANTAGES MAKE THE SUCCESSFUL DEVELOPMENT OF THE INSTRUMENT SUBSTANTIALLY LESS EXPENSIVE, FASTER, AND EASIER TO USE THAN CURRENT TECHNIQUES, WITH THE FURTHER ADVANTAGE THAT MEASUREMENTS CAN BE MADE AT THE CON- STRUCTION SITE. WHEN COUPLED WITH PHASE CONTRAST MICROSCOPY,X-RAY DIFFRACTION CAN BE A POWERFUL ADDITION TO THE ANALYTICAL TOOLS AVAILABLE FOR ASBESTOS DETERMINATION.