NASA Marine Target Series

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Summary

Wind Speed and Direction Instrument: Installation and Operation

Introduction

Overview of the Target wind speed and direction instrument and its power source requirements.

Pretest of Instrument

Procedure to check instrument completeness, connection, and basic functionality before mounting.

Installing the Display

Guidance on selecting a mounting location, drilling, wiring, and securing the display unit.

Installing the Sensor

Instructions for mounting the masthead sensor for optimal unobstructed airflow reception.

Masthead Alignment

Procedure to calibrate the wind direction sensor relative to the boat's heading for accurate readings.

Reading the Display

Explanation of how to interpret wind speed and direction indicators shown on the display unit.

The document describes the "Target Range Wind Speed & Direction" instrument, an aid to navigation designed for marine vessels. This device measures and displays wind speed and direction, providing crucial environmental data for sailors.

Function Description:

The primary function of the Target Range instrument is to provide real-time wind speed and direction information. It consists of a display unit, a masthead sensor, and a mounting kit. The masthead sensor, typically mounted at the top of the mast, detects the wind's speed and direction. This data is then transmitted to the display unit, which presents the information to the user. The wind speed is shown numerically in knots on the left side of the display, while the wind direction is indicated by an arrow on the right side, relative to the boat's heading. If the wind angle falls between two arrows, both will illuminate to show the general direction. The instrument is designed to operate from a vessel's 12V battery supply.

Important Technical Specifications:

Power Supply: 12V battery supply.
Current Consumption: Very small, requiring a 1/4 AMP fuse for protection.
Sensor Cable Length: Supplied with 15 meters of cable. A 10-meter extension cable is available if needed.
Wind Speed Units: Knots.
Display Illumination: Features an orange lead for illumination, which can be connected through a switch to control lighting along with other instruments.

Usage Features:

Pretest: Before mounting, users are instructed to pretest the instrument by plugging the sensor into the display unit, applying 12 volts, and gently spinning the wind cups and vane to check display operation.
Display Installation: The display unit should be installed in a convenient, flat, and dry position on a panel or bulkhead. A sponge rubber seal is provided to ensure good contact with the panel and prevent water ingress. The cable entry boss is intentionally not sealed to prevent misting of the display.
Sensor Installation: The masthead sensor is designed for mast mounting and should be placed where it can receive an unobstructed airflow from all directions. It must be substantially horizontal, but its orientation relative to the boat is unimportant. Mounting blocks and stainless steel self-tapping screws are provided for metal masts; suitable screws should be used for wooden masts.
Masthead Alignment: After installation, the wind direction display requires alignment. With the wind vane pointing forward along the boat's axis, the user must turn off the power supply, press and hold the "ALIGN" key, and then turn the power back on. Releasing the key will cause the indicating arrow to step to the correct position. Turning the supply off and on again completes the alignment.
Display Interpretation: Wind speed is shown numerically in knots on the left. Wind direction is shown by an arrow on the right, relative to the boat's heading.
Future Compatibility: The display includes "ALIGN" and two other keys, which currently have no function but are included for compatibility with future software developments.
Protection: A cover is provided to protect the display from physical damage when not in use.

Maintenance Features:

Fuse Protection: It is recommended to use a 1/4 AMP fuse to protect the instrument from faults.
Cable Management: Excess sensor cable should be stowed and not cut.
Water Ingress Prevention: The sponge rubber seal is critical for preventing water from entering the display unit's cavity. Cables should be routed vertically down from the unit to prevent water from tracking back.
Misting Prevention: The unsealed cable entry boss on the display unit helps prevent misting.

Additional Information:

The document also mentions that "The Target Range" system comprises other instruments, including:

Log: Measures 0-30 knots, trip distance, and total distance.
Echo Sounder: Measures 0.8-100 meters, features deep & shallow alarms, and keel offset.
Compass: Features selectable damping, a fully gimballed sensor, and displays 0- magnetic heading.

Important Note: The manual explicitly states that this instrument is "simply an aid to navigation and should not be considered as a substitute for good seamanship."