tender for supply of hard grove grindability index tester , hard grove grindability index tester: the instrument should be capable of determining relative ease of grind ability of coal, biomass ant conform to is 4433-1979. the instrument should be enclosed type dust and noise proof compact model. 1. grindability machine include stationary grinding bowl fabricated bowl fabricated from hardened and heat treated steel inner surface should be hard chromium plated so that there is no rusting. 2. steel balls set eight nos. of rust proof shinning steel grinding balls, each 25.400± 0.003 mm diameter. the balls shall be driven by upper grinding ring rotated at 19 to 21 revolutions/ minute is to be connected to a spindle and shall be driven by an integral 0.25 hp electric motor through reduction gears. 3. total weight and force total vertical force on the balls due to top ring, gear, weights and spindle is to be 284± 2 n and closely equivalent to a total mass of 29± 0.2 kg. 4. revolution counter fitted with pre set revolution counter and an automatic device for stopping the machine after 60± 0.25 revolutions. 5. sieves astm 16, astm 30 and astm 200 sieves with lid and receiver. 6. outer body m.s. outer body finished in rust- roof permanent powder coated to prevent corrosion. 7. electrical rating for use on 220/230v,50hz, single ph