USING THE COULTER LS-130 LASER DIFFRACTIO N ANALYZER FOR TESTING AND RESEARCH WORK ON BUILDING-MATERIALS

The COULTER LS 130 laser diffraction analyzer was tested specially for the particle size analysis of cement. In the particle size range from 1 to 900 mum the LS 130 uses laser diffraction for the measurement, a nd or particle sizes < 1mum it uses PIDS technology. The analysis can be carried out in one measuring operation. The cement is dispersed in propan-2-ol in the HFM module. With cement the liquid consumption of a bout 30 ml for one analysis is very low due to the integral filtering cycle. The dispersion in the FM module and the test results from the L S 130 show good reproducibility. The high resolution of the distributi on density curves, and hence the high information content, is made pos sible by the large number of measuring points (100 measuring channels) . Comparison with previous results shows good agreement with the resul ts of the sieve analysis (air-jet screening and micro-screening with u ltrasonic). The agreement between the results of sedimentation analysi s and laser diffraction is sufficiently accurate. The differences in t he sub-micron range require further investigation.