When used with the S60 Howard Cell, the K20 cover glass holds in place a0.1mm thickness of liquid is over the central island for analysis.
The cover glass has 25 calibrated fields of 1.382mm diameter through which to view the particles.
This cover glass removes the necessity of precise adjustment of the microscope magnification and calibration of a special eyepiece reticle in the original Howard Method, making it suitable for use with a modern zoom stereo microscope as well as a conventional compound microscope.
