What is “Mar”: blemish on the surface of a coating, extending over a particular area of the coating and visible due to the difference in the light-reflection properties of the area affected compared with the light-reflection properties of adjacent areas.
Mar resistance test for coatings is very similar with scratch resistance test, but this test uses arc（loop-shaped or ring-shaped）stylus to test the mar resistance of a single coating of a paint, varnish or related product, or the upper layer of a multi-coat system.
The product or system under test is applied at uniform thickness to flat panels of uniform surface texture. After drying/curing, the mar resistance is determined by pushing the panels beneath a curved (loop-shaped or ring-shaped) stylus which is mounted so that it presses down on the surface of the test panel at an angle of 45°. The load on the test panel is increased in steps until the coating is marred.
This test has been found to be useful in comparing the mar resistance of different coatings. It is most useful in providing relative ratings for a series of coated panels exhibiting significant differences in mar resistance. Kindly note this test does not specify a method using a pointed stylus, two of which are specified in ISO 1518-1 and ISO 1518-2, respectively. The choice between the three methods will depend on the particular practical problem.
BGD 536 Mar resistance Tester produced by Biuged confirms the newest international standard ISO 12137-2011, ASTM D 2197and ASTM D 5178. It can offer from 100g to 5,000g load to test panel.
◆ Working speed can be adjusted from 0 mm/s～10 mm/s
◆ Double adjusting balance device to reduce the test error because of level.
◆ Moveable working table is convenient for operator do more tests at different areas in the same test panel.
◆ Liftable balance arm can do mar test on the different thickness panels from 0mm～12mm
■ Motor Power：24W
■ Weights：1×100 gram, 2×200 gram, 1×500 gram, 2×1000 gram, 1×2000 gram
■ Loop-shaped Stylus： Made of chromium-plated steel and shall be in the form of a rod of 1,6 mm diameter bent into a “U” shape with an outside radius of（3.25±0.05）mm . With smooth surface and hardness is Rockwell HRC56 to HRC58 and its surface shall be smooth(roughness≤ 0.05 μm).
■ Stylus moving Speed：3 mm/s～10 mm/s（step: 0.5mm/s）
■ Angle between stylus with test panels：45°
■ Test panels Size：Less than 200mm×100mm（L×W）,Thickness is less than 10mm
■ Power：110-220V AC 50/60Hz
■ Overall Size：540×250×375mm（L×W×H）
■ Ordering Information：
BGD 536—Mar Resistance Tester
BGD 1008---Loop-shaped stylus
Add：NO.15, Fuzhong Rd., Zhongxin Town,
Zengcheng District, Guangzhou.China
E-mail：sara @ biuged.com
Add：RM.101, NO.3, Sicheng Rd.,
Gaotang Software Park, Tianhe District,
Add：No.1111, ZhongCai Industrial Park
1st floor，Zhu Feng Road, Qingpu District
Shanghai City, China.
Biuged Laboratory Instruments (Guangzhou) Co., Ltd. Guangdong ICP record number：11044672