scope:

- This specification covers instantaneous, continuously indicating synchro electrical propeller revolution indicating equipment consisting of transmitters, indicator-transmitters, and indicators for use in Naval shipboard interior communication system, circuit "K".

- The transmitters shall be of types designated in the following form, as specified (see 6.1).

The type designations shall be in accordance with the following symbols:

Basic indicator:

IC/ - Basic indicator for Naval interior communication equipment. Speed ratio between propeller shaft and transmitter shaft:

1 - 1 to 1

2 - 2 to 1

3 - 3 to 1

Type of drive: (Method of driving the transmitter from the propeller shaft or propulsion equipment).

A - Gear drive

B - Direct coupling

Operating speed range: 0-400 r.p.m. unless otherwise specified. (see 6.1).

- The indicator shall be of types designated in the following form, as specified (see 6.1):

The type designations shall be in accordance with the followings symbols:

Basic indicator:

IC/ - Basic indicator for Naval interior communication equipment.

Dial size:

2 - 2 inches

4 - 4 inches

6 - 6 inches

Mounting:

B - Bulkhead

P - Panel

U - Universal

Dial illumination:

R - Red

W - White

N - No illumination

Revolution counter:

C - With counter

N - Without counter

Speed range:

2 - 0 to 200 r.p.m.

4 - 0 to 400 r.p.m.

- The indicator-transmitter, unless otherwise specified (see 6.1), shall be of the type designated in the following form:

IC/6PNC4-Z

Separator:

A dash (-) shall be used to separate the major or basic features from the special features.

Special features:

Special features shall include the number of scales on the dial and number of pointers, as follows (and such other special features as may be specified (see 6.1):

Symbol Feature X Single scale and pointer Y Single scale and two concentric pointers Z Two concentric scales and pointers