Patent ID: 8359907

Claim:
A grass playing surface roughness measuring device, comprising: a carriage mounted on a plurality of surface engaging members by which the device can travel over a grass playing surface to be measured, wherein the surface engaging members comprise a plurality of wheels; a rotatable member contactable with the grass playing surface to roll thereover in use; a restraint which constrains the rotatable member to travel with the carriage; a transducer mounted on the carriage and coupled to the rotatable member and which can generate a signal representative of translation of the rotatable member relative to the carriage, wherein the rotatable member is a sphere or a strip of the surface of a sphere extending around the circumference of the sphere; and a plurality of bogey arrangements coupling the plurality of wheels to the carriage, the plurality of bogey arrangements being independently movable to adapt to variations in the grass playing surface over which the device travels so as to generally maintain the carriage in a substantially constant attitude relative to the playing surface.