Test sieves calibration samples supplied by Endecotts are microspheres formed of soda-lime glass that range from 3.35 mm down to 20 microns. Because of the precise nature and extent of the range of spheres, samples can be supplied to enable the accurate calibration of individual sieves to an accuracy of approx +/- 1µm.
The microspheres pass over, almost, the total surface of the sieve enabling more apertures to be examined than with any other method.
Consequently, calibration samples are one of the most accurate methods of sieve calibration available.
Functional Principle
How to accurately calibrate test sieves in a matter of minutes:
Select the calibration sample size that matches the aperture size of the sieve.
Place the sample on the sieve under test and shake for 2 minutes.
Weigh the passing sample and calculate the percentage.
Read the percentage passing along the graph.
The mean average aperture size in microns can now be read off against the graph which is supplied with your sample.