Hardness measurement of films using the "Paint Coating Authority" portable connector

In 1941, the Leningrad Branch of the Paint and Coatings Administration designed a new portable pendulum Tester.

After our research, it has been proved that this type of pendulum is not suitable for standard tests, because it is difficult to determine the glass value, and the difference between this instrument and the M-3 pendulum lies in the glass value itself It is unstable.   

The portable pendulum Tester is suitable for roughly measuring the hardness of the paint film on painted objects with a horizontal area of ​​not less than 50 x 100 mm under factory conditions (control during the manufacturing process, control when the product is finished). For various paint materials painted on glass, metal and wooden boards, this instrument can also be used to roughly measure the hardness. (Related Instruments: Congestion and)         

Apparatus (Fig. 127). A pendulum consisting of two parallel molybdenum-coated rings (diameter 100 mm, thickness 1.2 mm). The two rings are connected by three cylindrical pillars and the counterweight. On the pillar above the instrument is fixed a figure column that is screwed and supported on the counterweight; and a cylindrical adjustment load is placed on the cylinder. The plate containing the scale and the pendulum is fixed to the rear ring perpendicular to the diameter of the screwed-on post. The dial is semi-circular, and the Graduation is 0. 5°. The lower part of the swing needle is connected with a counterweight.

The test was carried out as follows. When the coating film is dry (relevant instrument: drying time measuring instrument), place the instrument on the painted utensils, occupying a small area, but not less than 50x100mm. After the instrument is calibrated, it should be carefully tilted in one direction until the pointer points to the scale "5" of the dial, and then the instrument well should be released carefully to start counting the amplitude. The amplitude of the vibration gradually decreases, and when the pointer of the instrument points to the scale "1", the calculation stops immediately. The number of vibrations is an indicator of hardness. The greater the vibration number, the greater the hardness.

The hardness of the standard paint film obtained by the following method can be used for comparison. On the sample plate made of the same material as the test piece, according to the technical conditions, paint the paint material that meets the various indicators in the current production; compare the vibration number measured on the standard plate with that on the tested coating film By comparing the measured vibration numbers, the hardness of the tested paint film can be expressed.