Contact Us
TEL: 86-010-82675282
Fax: 86-010-82675633
E-mail: susan@kaida17.com
Address: Floor 2, Building C, No. 3 courtyard, Jinbangyuan North Street, Xisanqi, Changping District, Beijing 100096, PR CHINA
Home > Knowledge > Content
What are the requirements of the portable hardness tester for the surface of the test sample?
Jan 28, 2019

What are the requirements of the portable hardness tester for the surface of the test sample?


Let's talk about the following, what is the requirement of the portable hardness tester for the surface of the test sample?


● The surface temperature of the sample should not be too high and should be less than 120 °C.


● The surface roughness of the sample should not be too large, otherwise it will cause measurement error. The surface to be tested of the sample must be exposed to metallic luster and be flat, smooth and free of oil.


●Requirement for sample weight: For heavy-duty samples larger than 5kg, no support is required; test pieces with a weight of 2-5kg, test pieces with overhanging parts and thin-walled test pieces should be supported by objects during testing to avoid impact. The force causes the specimen to deform, bend and move. For medium-sized specimens, they must be placed on a flat, strong surface. The specimens must be placed in a smooth position without any sloshing.


● Curved specimen: The test surface of the specimen is preferably flat. When the measured surface radius of curvature R is less than 30mm (D, DC, D+15, C, E, DL type impact device) and less than 50mm (G type impact device), the test shall use a small support ring or a profiled support. ring.


● The sample should have sufficient thickness. The minimum thickness of the sample should meet the requirements of Table 3.


● For specimens with a hardfacing layer, the depth of the hardened layer shall comply with Table 3.


●Coupling


- For light specimens, it must be tightly coupled with a strong support. The two coupling surfaces must be flat and smooth, and the amount of coupling agent should not be too much. The test direction must be perpendicular to the coupling plane;


- When the sample is a large-area plate, long rod, or bent piece, even if the weight and thickness are large, the test piece may be deformed and unstable, resulting in inaccurate test values, so it should be reinforced or supported on the back side of the test point.


●The magnetic value of the sample itself should be less than 30 Gauss


Previous: Dual-use coating thickness gauge features

Next: Measuring principle of coating thickness gauge