Abstract: The invention relates to a test apparatus for measuring frictional properties of a fluid or of a specimen immersed in a fluid. A first specimen holder holds a first specimen in the fluid being tested; the first specimen in contact with a surface of a second specimen, in a second specimen holder. A measurable load is applied between the two specimens, and an oscillatory driving means oscillates the first specimen holder relative to the second specimen holder. Force measuring means measures the frictional force between the two specimens. The specimen holders are in a sealed pressure chamber allowing the test to be carried out under alternative pressures. A push rod provides the oscillating motion of the first specimen holder inside the pressure chamber so the pressure is maintained during the test. The pressure chamber is removable and maintains pressure or vacuum even when removed from the test apparatus.

Abstract: The invention relates to a traction or friction measuring apparatus and method of calibration.

Abstract: The invention relates to a traction or friction measuring apparatus and method of calibration.

Abstract: The invention relates to a test method and apparatus for measuring the frictional properties of a fluid and comprises; a first specimen holder which is adapted to hold a first specimen in the fluid being tested in contact with a second specimen surface of a second specimen in a second specimen holder, with means for applying a measurable load between the two specimens, and with oscillatory driving means for oscillating at least one of the specimen holders along a first direction, and a motion inducing means, for inducing a motion between the first and second specimen holders in a second direction to induce a compound movement between the specimens which has been found results in more accurate readings. The first specimen holder is connected to a shaft which is induced to move in the first direction being the direction of the length of the shaft and the motion inducing means for inducing a motion in a second direction may be an off-centre counter weight located on the shaft.

Abstract: The invention relates to a test method and apparatus for measuring the frictional properties of a fluid and comprises; a first specimen holder which is adapted to hold a first specimen in the fluid being tested in contact with a second specimen surface of a second specimen in a second specimen holder, with means for applying a measurable load between the two specimens, and with oscillatory driving means for oscillating at least one of the specimen holders along a first direction, and a motion inducing means, for inducing a motion between the first and second specimen holders in a second direction to induce a compound movement between the specimens which has been found results in more accurate readings. The first specimen holder is connected to a shaft which is induced to move in the first direction being the direction of the length of the shaft and the motion inducing means for inducing a motion in a second direction may be an off-centre counter weight located on the shaft.

Abstract: Traction and/or friction testing apparatus is described having inter-engaging, rotating, traction surfaces, the surfaces being independently driven to generate traction or friction forces therebetween. A force measuring means is provided to measure the resulting traction or friction force. The apparatus is characterised in that all forces applying in the traction measurement loop are directly readable, or elastic, thus eliminating internal friction and allowing an accurate indication of the traction or friction force. The apparatus is particularly useful for measuring rolling/sliding traction and friction.