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Resilience

Dunlop Tripsometer - R2 / R2A

Features   Measures rebound resilience directly   Frictionless bearings allow more accurate readings   Two versions available, with & without air compressor   Electrically operated pendulum release ensures no energy is imparted to pendulum   Can accept Schopper rings or 8mm square test pieces   High temperature pretest oven and low temperature test piece holder available   Can be easily fitted with R3 Data Computer(cat.Ref.R3) with digital readout   To find out more about this product contact Wallace

Introduction

Resilience is the ability of a rubber vulcanisate to return the energy used to deform it, during its recovery from the deformation.

The rebound resilience, which is the property measured by the Dunlop Tripsometer, is the percentage ratio of the energy returned during an impact to the energy input.

The apparatus contains a pendulum in the form of a solid steel disc 419 mm in diameter, which has a striking ball 4 mm in diameter attached to its periphery at a distance of 250 mm from the centre of the disc. The ball and its mounting bracket add an unbalanced mass or 60 g to the disc. The pendulum is mounted in special frictionless Wallace air bearings, which are virtually frictionless, allowing greater accuracy in setting the initial displacement and ready of the rebound angle.A scale and pointer indicate the angular displacement of the pendulum.

An adjustable stop is attached to the scale and contact of this stop with the pin sets the initial displacement of the pendulum prior to a test. An electrical Pendulum Release Mechanism which releases the pendulum, avoids magnetic hold-up or energy being imparted to the pendulum on release. The mechanism is easily removed to permit the free passage of the striker when required.

The test piece holder contains an electrical heating element and an electronic temperature controller enables the test piece to be kept at the required temperature. A special low Temperature Test Piece Holder is available at extra cost - see note R.2/7 below. The small plate hinges to cover the form of the test piece and helps to prevent the loss of heat. The striking ball passes through a hole in this plate. Alternative adaptors are available to receive either the 8 mm square test piece or a Schopper disc of 44.6 mm in diameter.

The Schopper disc is preferable since it can be held securely against the back support of the test piece holder by means of a vacuum. (An electric Vacuum Pump is available under ref. X.2). A special adjustable stop is provided to prevent the striker being damaged should the pendulum be released with no test piece in position.

A polished hardwood, draught-proof cabinet is supplied which is fitted with transparent perspex panels and a hinged access door. The cabinet has no base and is easily removed or replaced without disturbing the machine.

The Wallace Dunlop Tripsometer Ref. R.2 & R.2A conforms to BS 903 Part A8.

Models Available

Two models are available:

Optional Extras

Ref. R.3 - Rebound Resilience Data Computer

It automatically computers resilience and displays the result as a percentage on a digital readout. It reduces testing time, avoids the neccessity for calculations and enables unskilled operators to obtain accurate and consistent results.

Specifications

See the table below for a run-down of this product's specifications.