As Per IS : ASTM: C 403

It is used for finding out the rate of hardening of mortars sieved form concrete mixtures, by means of penetration needles of different cross-sectional areas.  

Specifications:

The instrument consists of a barrel housing a calibrated spring and a stem graduated from 0- 70 kg X 1 kg. Six interchangeable penetration needles of areas 645, 323, 65, 32 and 16 mm sq. are provided.

The penetration resistance is measured by the force exerted to penetrate the mortar by 25 mm and is indicated by a sliding ring on the stem, which is graduated.

Needle shanks are marked at every 12.5 mm. Compete in a wooden carrying case.