Squeegee Hardness Tester GS-719N       Made by TECLOCK CORPORATION in Japan
Introduction
DUROMETER, RUBBER and PL ASTIC HARDNESS TESTER is produced from a thought that there might be a manner to express anambiguous sense of human feelings about the hardness, e.g. slightly soft, by a numeral value which can be compared by some physical manner, and that it might be possible with an elastic material which can be distorted by a human force.
The basic concept of this idea is following as shown in the below figure.When the Indent or of specific shape gives a distortion onto the surface of a specimen with the pressure produced by the specific spring load,the specimen produces a resilient force against the pressure load.
The hardness  means the depressed  Indent or amount of Indent or at the time when the resilient force becomes equal to the pressure load. Since so called the Indent or of specific shape  and the specific load are the values given by human experience or experimental sense, the value consequently got is a relative physical amount with no unit. 
Screen printing requires the use of different hardness scrapers to match different printing processes.Different scraping hardness, the support of screen printing is not the same.