Chapter 2 Anemometer Systems

CHAPTER 2

ANEMOMETER SYSTEMS

CHAPTER LEARNING OBJECTIVES

Upon completion of this chapter, you should be able to do the following:

Describe the synchro signal amplifier and its

Describe the two types of anemometer (wind

direction and speed indicating) systems.

principles of operation.

Describe the procedures in performing preven-

Identify the major components of anemometer

tive maintenance on anemometer systems.

systems.

Describe the procedures to follow in trouble-

Describe the purpose and operation of the major

shooting and repairing the components in ane-

components.

mometer systems.

Describe the crosswind and headwind computer

Describe synchros and the procedures for zero-

system

ing different types of synchros.

Detector

The anemometer (wind direction and speed indica-

tor) system, circuits HD and HE, provides instantaneous

The detector (fig, 2-1) is a dual-purpose instrument

and continuous indication of wind direction and speed

employing two type 18CX4 synchros for transmitting

relative to the ship's heading and speed. Wind direction

the instantaneous undamped signals representing wind

and speed information is important for combat systems

direction and speed to the transmitter and/or computers.

operations, flight operations, and maneuvering.

Throughout this chapter we will use the term wind

The detector should be mounted on a mast or yard-

direction and speed indicator systems interchangably

arm where it will receive unobstructed wind flow from

with the term anemometer systems.

all directions. Be careful not to submit the detector to

wind currents and eddies from nearby objects. Avoid a

WIND DIRECTION AND SPEED

location where flue gases or exhaust currents will strike

INDICATOR SYSTEMS

the detector. Equipment cannot be installed in the area

that will interfere with the detectors.

There are two types of wind indicating systems, type

F and type B. The type F system provides both 115-volt,

The direction synchro in the detector is mounted in

60- and 400-Hz outputs. The type B system provides

a vertical support and is coupled to a plastic vane

only 115-volt, 60-Hz outputs. Most ships have two

assembly. A speed synchro enclosed in synchro housing

systems installed; one for the port side of the ship and

is mounted in the head of the vane and is geared to a

one for the starboard side of the ship.

screw-type rotor assembly that senses wind speed. The

angular position of the vane and rotating speed of the

MAJOR COMPONENTS

rotor assembly are sent to their respective synchros in

the transmitter. Electrical connections are made to the

The major components of the system are the wind

speed synchro through the collector ring assembly and

direction and speed detector, the wind direction and

brushes on the brush holder assembly.

speed transmitter, and the wind direction and speed

Wind direction is determined by the position of the

indicator. Throughout this chapter we will refer to these

vane and is shown as degrees off the bow of the ship.

components as the detector, the transmitter, and the

The direction synchro is set to electrical zero when the

indicator. The synchro signal amplifier is also a com-

vane points directly to the bow. As the wind positions

ponent of these systems.

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