Published online by Cambridge University Press: 01 June 2009
A portable apparatus is described for indicating continuously as a measure of pulsation ratio the proportion of the cycle during which a liner is more than half open. With the machine set for milking, a probe with an electric switch which opens as the liner collapses is inserted in one liner, the others being closed with rubber bungs. The pulses of current from the switch are fed to a damping circuit so that the proportion of the cycle time during which current flows can be read on a meter. The problem of interpreting the various measures of pulsation ratio are discussed.