1. Sensitiveness of Governors - The Sensitiveness is defined as the ratio of the difference between the maximum and minimum equilibrium speed to the mean equilibrium speed.

Let,

$N_1$ = Minimum equilibrium speed,

$N_2$ = Maximum equilibrium speed and

N = Mean equilibrium speed = $\frac{N_1 + N_2}{2}$

$\therefore$ Sensitiveness of the governor

$= \frac{N_2 – N_1}{N} = \frac{2(N_2 – N_1)}{N_1 + N_2}$

$= \frac{2 (w_2 – w_1)}{w_1 + w_2}$ ......(In terms of angular speeds)

2. Stability of governors – A governor is said to be stable when for every speed within the working range there is a definite configuration i.e. there is only one radius of rotation of the governor balls at which the governor is in equilibrium.

3. Isochronous Governors – A governor is said to be isochronous when the equilibrium speed is constant (i.e. range of speed is zero) for all radii of rotation of the balls within the working range, neglecting friction.

4. Hunting – A governor is said to be hunt if the speed of the engine fluctuates continuously above and below the mean speed.

This is caused by a too sensitive governor which changes the fuel supply by a large amount when a small change in the speed of rotation takes place.

5. Effort and power of a Governor – The effort of a governor is the mean force exerted at the sleeve for a given percentage change of speed* (or lift of the sleeve)

The power of a governor is the work done at the sleeve for a given percentage change of speed. It is the product of the mean value of the effort and the distance through which the sleeve moves.

Mathematically,

Power = Mean effort x Lift of sleeve.