# CMRR

Common-mode rejection ratio - the ratio of the gain of an amplifier for difference signals between the input terminals, to the gain for the average or common-mode signal component.

## Related Terms

### HARMONIC

1. A sinusoidal quantity having a frequency that is an integral multiple of the frequency of a periodic quantity to which it is related. 2. A signal having a frequency which is an integral multiple of the fundamental frequency.

### FILTRATION (BETA) RATIO

The ratio of the number of particles greater than a given size in the influent fluid to the number of particles greater than the same size in the effluent fluid.

The ratio of actual work output of a heat engine to the ideal output.

### BETA-RATIO (ß-RATIO)

The ratio of the number of particles greater than a given size in the influent fluid to the number of particles greater than the same size in the effluent fluid, under specified test conditions (see 'Multi-Pass Test').

### BULK MODULUS (OF ELASTICITY)

A ratio of normal stress to a change in volume. A term used in determining the compressibility of a fluid. Data for petroleum products can be found in the International Critical Tables.

### HOP

Travel of a radio wave to the ionosphere and back to earth. The number of hops a radio signal has experienced is usually designated by the expression one-hop, two-hop, multihop, etc

### HOMING

Navigation toward a point by following a signal from that point. Radiobeacons are commonly used for homing.

### AIR-FUEL RATIO

The ratio weight, or volume, of air to fuel.

### SENSIBLE HEAT FACTOR

The ratio of sensible heat to total heat.

### POISE

A measure of viscosity (absolute viscosity) numerically equal to the force required to move a plane surface of one square centimeter per second when the surfaces are separated by a layer of fluid one centimeter in thickness. It is the ratio of the shearing stress to the shear rate of a fluid and is expressed in dyne seconds per square centimeter (DYNE SEC/CM2); 1 centipoise equals .01 poise.