# SEMILOGARITHMIC COORDINATE PAPER

Paper ruled with two sets of mutually-perpendicular parallel lines, one set being spaced according to the logarithms of consecutive numbers, and the other set uniformly spaced.

## Related Terms

### DIRECTIVITY FACTOR

1. The ratio of radiated sound intensity at a remote point on the principal axis of a loudspeaker or other transducer, to the average intensity of the sound transmitted through a sphere passing through the remote point and concentric with the transducer; the frequency must be stated.
2. The ratio of the square of the voltage produced by sound waves arriving parallel to the principal axis of a microphone or other receiving transducer, to the mean square of the voltage that would be produced if sound waves having the same frequency and mean-square pressure were arriving simultaneously from all directions with random phase; the frequency must be stated.

### POISSON RATIO

The ratio of the transverse contracting strain to the elongation strain when a rod is stretched by forces which are applied at its ends and which are parallel to the rod's axis.

### PLANE STRESS

A state of stress in which two of the principal stresses are always parallel to a given plane and are constant in the normal direction.

### PI FILTER

A filter that has a series element and two parallel elements connected in the shape of the Greek letter pi ().

### PIGTAIL SPLICE

A splice made by twisting together the bared ends of parallel conductors.

### PARALLEL CUT

A group of parallel holes, not all charged with explosive, to create the initial cavity to which the loaded holes break in blasting a development round. Also known as burn cut.

### PARALLEL AXIS THEOREM

A theorem which states that the moment of inertia of a body about any given axis is the moment of inertia about a parallel axis through the center of mass, plus the moment of inertia that the body would have about the given axis if all the mass of the body were located at the center of mass.

### PARALLEL SERIES

Circuit in which two or more parts are connected together in parallel to form parallel circuits, and in which these circuits are then connected together in series so that both methods of connection appear.

### PARALLEL RELIABILITY

[SYS ENG] Property of a system composed of functionally parallel elements in such a way that if one of the elements fails, the parallel units will continue to carry out the system function.