The Ottawa Test jig consists of a square test cell with solid walls and an open
base which can be fitted with one of a variety of plates which are included in
the kit. A square plunger is fitted to the machine crosshead and provides the
compression. The test method involves weighing a suitable quantity of sample
which is placed in the cell with either a slotted or a perforated plate fitted. In
either case the result is determined by measuring the resulting force required
to extrude the sample