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Laboratory sand rammer:
This rammer is designed for preparing DIN standard test specimens for the determination of compression, tensile, transverse, shear and splitting strength by compacting a predetermined weight of sand in a tube, or a core box of the required shape. This is achieved by dropping a known weight a fixed distance, and using the energy produced to compact the sand.

The Density Indicator is designed to be mounted on top of the Sand Rammer. The position of the pointer is controlled by the length of the rammed sand specimen. Three scales are engraved on a curved plate, two of which indicate density in kilograms per cubic metre, one from 1400 to 1800 kilograms per cubic metre when a 157 gram weight of sand is used and the other reading from 1280 to 1650 kilograms per cubic metre, when a 143 gram sample weight is used. The third (central) calibration indicates the exact weight (in grams) of sand needed to form a 50 mm diameter x 50 mm height specimen after ramming a sand specimen weighing 157 grams.

The Density Indicator is secured to the metric Sand Rammer by means of two screws provided, using the two tapped holes on the back of the lug on which the tolerance scale is mounted. It is positioned correctly by placing the 50 mm gauge block provided, on a pedestal cup and lowering the ram end on to it. The main arm and the indicating pointer should then be approximately parallel. Final adjustment is made by slackening the three domed nuts behind the scale and moving it until the pointer indicates exactly 50 mm on the scale.

Test procdure:

1. Weigh out 157 grams of sand and place in a standard 50 mm diameter specimen tube, using a pedestal cup. Lift the indicator arm to the right so that it comes to rest on the stop bracket and does not interfere with the action of the rammer.

2. Ram the sand with three drops of the rammer or to a chosen mould hardness. Move the indicator arm until it rests on the top of the rammer plunger and read the density of the rammed sand in kilograms per cubic metre on the left hand scale.

3. If the density is less than 1400 kg per cubic metre use a sample weight of 143 grams and proceed as outlined above, reading the right hand scale.

4. To obtain the weight of sand needed to form a metric 50 mm diameter specimen, weigh out 157 grams of sand, ram in the usual manner and read the weight in grams on the centre scale.