Airmar Ultrasonic TRIDUCER UDST800 Owner's Manual And Installation Instructions

OWNER'S GUIDE & INSTALLATION INSTRUCTIONS
Thru-Hull:
Retractable with Valve
Ultrasonic TRIDUCER
Model UDST800
Patent http://www.airmar.com/patent.html
Follow the precautions below for optimal
product performance and to reduce the risk of
property damage, personal injury, and/or death.
WARNING: Always wear safety glasses, a dust mask,
and ear protection when installing.
WARNING: The valve is not a watertight seal! Always
install the insert or blanking plug. Be sure it is fully
inserted into the housing and the cap nut is screwed on
completely for a watertight seal.
WARNING: The O-rings must be intact and well
lubricated to make a watertight seal.
WARNING: The YELLOW O-ring must be in place near
the top of the insert to make a watertight seal.
WARNING: To retrofit the insert in a housing without a
valve, the insert must have a BLACK O-ring near the top
to make a watertight seal.
WARNING: Stainless steel housing in a metal hull—Be
sure the washer contacts the hull. Do not tighten the hull
nut with the washer against the isolation bushing, as the
housing will not be firmly installed.
WARNING: Always attach the safety wire to prevent the
insert or blanking plug from backing out in the unlikely
event that the cap nut fails or is screwed on incorrectly.
WARNING: Immediately check for leaks when the boat is
placed in the water. Do not leave the boat unchecked for
more than three hours. Even a small leak may allow
considerable water to accumulate.
CAUTION: Plastic housing—Never use a fairing with a
plastic housing; the protruding sensor would be
vulnerable to damage from impact.
CAUTION: Metal housing—Never install a metal
housing in a vessel with a positive ground system.
CAUTION: Stainless steel housing in a metal hull—A
stainless steel housing must be isolated from a metal hull
to prevent electrolytic corrosion. Use the isolation
bushing supplied.
CAUTION: Never pull, carry, or hold the sensor by its
cable. This may sever internal connections.
CAUTION: The arrow on the top of the insert must point
forward toward the bow to align with the water flow.
CAUTION: Never use solvents. Cleaner, fuel, sealant,
paint, and other products may contain solvents that can
damage plastic parts, especially the transducer's face.
IMPORTANT: Read the instructions completely before
proceeding with the installation. These instructions
supersede any other instructions in your instrument
manual if they differ.
Record the information found on the cable tag for future reference.
Part No._________________Date___________Frequency________kHz
Multisensor
®
Smart Sensor
™

Applications

• Not recommended for boats designed to pull air under the hull.
• Plastic housing recommended for fiberglass or metal hull only.
• Bronze housing recommended for fiberglass or wood hull.
• Stainless steel housing compatible with all hull materials.
• Best performance on a hull deadrise angle through 7°.

How the Ultrasonic Speed Sensor Works

The speed sensor uses ultrasonic pulses to collect echoes from
small particles in the water as they pass under two transducers
embedded in the insert (Figure 1). These transducers monitor the
particles in their respective beams. As the boat travels through the
water, both transducers 'view' the same stream of particles.
Because it takes time for particles to travel between the two
transducers, the aft transducer detects the particles later than
does the fore transducer. By measuring this time lapse, the
instrument calculates the boat speed. If the boat is airborne, even
for a short time, or in highly aerated water, the sensor will
measure an incorrect speed.
Never install a plastic housing in a wood hull, since swelling of
the wood can possibly fracture the plastic.
Never mount a bronze housing in an aluminum hull because
electrolytic corrosion will occur.
Recommended for aluminum hulls to prevent electrolytic
corrosion provided the stainless steel housing is isolated from
the metal hull.
Accommodates up to a 22° deadrise angle.
scanning transducer
hull
FORE
vessel direction
particle stream
Figure 1. Monitoring particles in the water
Copyright © 2002 Airmar Technology Corp.
UDST800
plastic
low profile
P617V housing
AFT