Runway Friction Testing Equipment

BASIC PRINCIPLE AND GENERAL DESCRIPTION
The measuring system consists of a measuring wheel which is mechanically geared to one of the rear main wheels of the base car. The gear ratio is such that when moving along the runway the measuring wheel cannot follow the runway surface freely but rolls with a certain, fixed slip ratio.



The friction against the runway surface, in combination with the vertical load on the measuring wheel, creates forces on the measuring wheel mechanism and these forces are continuously measured by the electronic sensor system. The signals from the sensors are processed in the STMC Measuring Computer system in the SVFT and the Friction coefficient, or the Friction number, the relation between the horizontal and the vertical forces acting on the measuring wheel, is continuously calculated and presented by the windows based measuring computer. The result can be display in a colour graf on the screen, printed in diagram or graf form on paper by a printer. The measuring results can also be transmitted direct to a receiver by radio link (Freewave). GPS system and/or be part of the data fed into a general system for reporting runway friction conditions. The computer in the SVFT has been preprogrammed to measure and report runway friction in accordance with standards and regulations issued by ICAO, FAA etc.

MEASURING COMPUTER SYSTEM
The STMC measuring computer system that is a standard laptop (Touchscreen) windows based system have unlimited storage of measuring data, All data are handled by one computer system for analyzing, reporting, sending or storing measuring data. The connection is wireless (peer to peer) or wired to suit the customers need. The SVFT is using wired as standard.

SELF WATERING SYSTEM
The self watering system on the SVFT is build-into the backseat of the car. The ASTM approved water nozzle gives the correct width of thickness of the water strip in front of the measuring wheel. The usage of water pressure depends on the measuring speed. The water tank has a capacity for 7000 meters.