Theory Tribometer

a simple tribometer described hanging mass , mass resting on horizontal surface, connected each other via string , pulley. coefficient of friction, µ, when system stationary, determined increasing hanging mass until moment resting mass begins slide. using general equation friction force:

f
=
μ

n



{\displaystyle f=\mu \mathbb {n} }

where n, normal force, equal weight (mass x gravity) of sitting mass (mt) , f, loading force, equal weight (mass x gravity) of hanging mass (mh).

to determine kinetic coefficient of friction hanging mass increased or decreased until mass system moves @ constant speed.

in both cases, coefficient of friction simplified ratio of 2 masses:

μ
 
=

m

h



/


m

t




{\displaystyle \mu \ =m_{h}/m_{t}}

in test applications using tribometers, wear measured comparing mass or surfaces of test specimens before , after testing. equipment , methods used examine worn surfaces include optical microscopes, scanning electron microscopes, optical interferometry , mechanical roughness testers.