For unattened grinding of non gummy and non fibrous materials. Extensively used for preparing coal samples for calorific tests. The motor revolves and the pestle moves back and fourth in a pattern reaching all parts of the mortar. Its metallic housing with a F.H.. Motor driven detachable turn table of cast aluminium has adjustale posts to hold mortars of 75 to 135 m.m. dia. Thew arm of the pestle drivintg mechanism has inged, heavy head which cn be raised to inspect or remove the sample or additional material to be added as disered. A build-in timer permits selection of grinding operation upto 60 min. The grinding vessel and mortar are all completely covered by a clear acrylic cover. To opeate on 220 V.A.C.