S. C. Dey & Co. Manufactures Pellet Hardness Tester for Carbon Black. S. C. Dey & Co. Is an ISO 9001 certified company. The Pellet Hardness Tester for Carbon Black is made as per ASTM standards. Its load cell capacity is 200 gm, Resolution: 0.01 gm and it works on 220/240 Volt, AC. 50 Hz, 1 Ph, Mains.