is identical to spring Type, except that the penetration pressure on the needle
is conveyed through a hydraulic system to a hydraulic pressure gauge. This system
permits a greater control over rate of penetration because of better visibility
of load indication.
Specification: Comprises hydraulic proctor needle system
complete with a pressure gauge fixed at eZIly readable Angle reading 0-70kg x
2kg. A set of needle points consisting one each 0.25, 0.5, 1.0, 3.5, and 6.0wq.cm.
and a tommpy pin.
Graduation at every 12.5 mm to indicate depth of penetration
are marked on longer stem for use with needles of larger areas. Smaller stem is
also graduated at every 12.5 mm and is used with needles of smaller areas. Complete
as above in a wooden carrying case.