AASHTO T 278-90 (2021)

This method covers the procedure for measuring surface frictional properties using the British Pendulum Skid Resistance Tester. A method for calibration of the tester is included in the Annex.

The British Pendulum Tester is a dynamic pendulum impact-type tester used to measure the energy loss when a rubber slider edge is propelled over a test surface. The tester is used for laboratory as well as field tests on flat surfaces, and for polish value measurements on curved laboratory specimens from accelerated polishing wheel tests.

The value measured, British Pendulum (Tester) Number, BPN, for flat surfaces and polish values for accelerated polishing wheel specimens, represents the frictional properties obtained with the apparatus and procedures stated herein, and does not necessarily agree or correlate with other slipperiness measuring equipment results.