Sieves can be calibrated precisely and economically using Endecotts Glass Microspheres. This method has the advantage of quick calibration without any special equipment and can be done by anyone familiar with sieving procedures.
This process allows for analysis of over 80% of the sieve surface. The glass sample beads are certified using electroformed sieves NIST & NPL traceable and are accurate to .01 mm for the smaller aperture sieves.
The calibration samples are microspheres formed from glass that range from 3.35 mm down to 20 µm sizes. The single shot bottles remove operator sampling errors. Each sample batch is supplied with a Calibration Certificate
Calibration Sample Procedure:
Select the calibration sample size that matches the sieve aperture size.
Place the 'Single Shot' sample on the sieve under test and shake for 2 minutes.
Weigh the sample again and calculate the percentage passing through the sieve.
Includes 5 test shots per selection
Simply read off the percentage passing along a graph like this supplied with every sample.
The mean aperture size in micrometers can be read off here against the graph.
