These rotating meters detect the rotation of the fly wheel for the ship engine, or of the slit panel equipped to the propeller shaft etc., using a proximity sensor. The detected pulse is converted into voltage signals in proportion to the rotation. These signals are indicated as the rotation direction and the frequency of the engine or the propeller shaft, on the receiver (indicator) located in a remote area (e.g. wheelhouse, engine control room).

Attached to instruction manual of Ships and marine technology -
Propeller shaft revolution indicators(JIS F 8521).
:Minimum safe distance list from the magnetic compass

Production of other various indicators is available, grounded on Nunotani's technologies for producing rotating meters and indicators that have been established over many years.

Indicator dimensions	See the indicator for rotating meters.
Input	0 - 10V, 0 - ±10V, 4 - 20mA etc.