Page 1
OWNER’ S GUIDE & INSTALLATION INSTRUCTIONS
In-Hull: Adjustable-angle
Depth Transducer
Models: P79, P79S Smart™ Sensor
Chirp Models: P75M, P95M
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.
17-217-01 rev. 15 07/18/18
WARNING: Always wear safety glasses, a dust mask,
and ear protection when installing.
CAUTION: Chirp transducer—Always operate the
transducer in liquid. Operating in air will allow the
transducer to overheat resulting in failure.
CAUTION: Fiberglass hull—The fiberglass hull
below the transducer must be SOLID. The transducer
will not transmit through coring material such as foam
or balsa wood.
CAUTION: Chirp transducer—Do not install in the
engine compartment or other hot place. The
transducer may fail if the temperature of the liquid in
the tank exceeds 60° C (140° F).
CAUTION: Never pull, carry, or hold the transducer by
the cable. This may sever internal connections.
CAUTION: Do not use an epoxy adhesive because it
is too brittle.
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: Please read the instructions completely
before proceeding with the installation. These
instructions supersede any other instructions in the
instrument manual if they differ.
Applications
• For fiberglass hulls only
• Recommended for high-speed powerboats and racing sailboats
• Accommodates a deadrise angle from 2° to 22°
Tools & Materials
Safety glasses
Dust mask
Ear protection
Adhesive tape
Pole
Detergent (some installations)
Weak solvent (such as alcohol)
Disk sander (some installations)
Thin sealable plastic bag (some installations)
Cable ties (some installations)
Water-based lubricant (such as K-Y® jelly) (some installations)
Angle finder
Record the information found on the cable tag for future reference.
Part No._________________Date___________Frequency________kHz
Carpenter’s square
Pencil
Silicone sealant (such as GE
Screwdriver
Petroleum jelly
Propylene glycol (non-toxic antifreeze/coolant) 71ml (2.4 fl. oz.)
Level
Grommet(s) (some installations)
Installation in a cored fiberglass hull (page 4):
Electric drill
Hole saw 100mm or 4"
Miniature disk sander (such as Dremel
Repair epoxy (such as Pettit Flexpoxy 7076) or resin
Paper cup (some installations)
Stirrer (some installations)
®
Silicone I or Silicone II)
® rotary sander)
Mounting Location
About Fiberglass Hulls
The fiberglass hull below the transducer must be solid. Since the
hull absorbs acoustic energy, transmitting through the hull
reduces the transducer’s performance. Fiberglass hulls are often
reinforced in places for added strength or to reduce weight. These
cored areas contain balsa wood or structural foam which are poor
sound conductors. Do not locate the transducer over coring.
Placement
CAUTION: Do not mount the transducer in line with or near water
intake or discharge openings or behind strakes, fittings, or hull
irregularities that will disturb the water flow.
Choose a location:
• Where the fiberglass is SOLID (no air bubbles are trapped in
the fiberglass resin) and where no coring, flotation material, or
dead air space is sandwiched between the inside skin and outer
skin of the hull.
• Where the hull below the transducer will be in contact with the
water at all times.
• Where the water flowing under the hull is smoothest with a
minimum of bubbles and turbulence (especially at high speeds).
• Away from interference caused by power and radiation sources
such as: the propeller(s) and shaft(s), other machinery, other
echosounders, and other cables. The lower the noise level, the
higher the echosounder gain setting that can be used.
• Where the transducer beam will not be blocked by the keel or
propeller shaft(s).
• Where the deadrise angle does not exceed 22°.
• Where there is space inside the vessel for the height of the unit,
tightening the locking ring, and installing the transducer.
• Chirp transducer—Mount in a cool well-ventilated area away
from the engine to avoid overheating. The transducer may fail if
the temperature of the liquid in the tank exceeds 60° C (140° F).
Page 2
1/3
LWL
(Load Waterline Length)
outboard and / IO
stepped hull
displacement hull
planing hulls
pressure waves
150- 300 mm
(6-12")
inboard
Testing the Selected Mounting Location
Establishing a Performance Baseline
The results of this test are used as a basis of comparison to
determine the best in-hull location for the transducer.
1. Take the boat to the maximum depth in which you will be
operating the echosounder. If deep water is not available, find a
location with at least 30m (100').
2. Connect the transducer to the echosounder.
3. Tape the transducer to a pole with the cable side up. Hold it
over the side of the boat with the active face fully submerged
and parallel to the water surface (Figure 2).
4. Observe the echosounder’s performance and the depth reading.
Testing the Location
While the boat is at the same site (depth of water), test the
transducer inside the hull at the mounting location. Use one of the
methods below:
fin keel sailboat
full keel sailboat
Figure 1.
Best location for the transducer
Copyright © 2005 - 2016 Airmar Techn ology Corp.
Boat Types (Figure 1)
• Displacement hull powerboat—Locate 1/3 of the way back
along the LWL and 150– 300 mm (6–12") off the centerline. The
side of the hull where the propeller blades are moving
downward is preferred.
• Planing hull powerboat—Mount well aft, on or near the
centerline, and well inboard of the first set of lifting strakes to
ensure that the transducer is in contact with the water at high
speeds. The side of the hull where the propeller blades are
moving downward is preferred.
Outboard and I/O—Mount just forward of the engine(s).
Inboard—Mount well ahead of the propeller(s) and shaft(s).
Stepped hull—Mount just ahead of the first step.
• Fin keel sailboat—Mount to the side of the centerline and
forward of the fin keel 300– 6 00 mm (1 –2').
• Full keel sailboat—Locate amidships and away from the keel
at the point of minimum deadrise angle.
A.For a location near the stern and a minimal deadrise angle—
Clean away any build-up of dirt and / or grease using detergent
or a weak solvent such as alcohol. Place the transducer against
the hull and allow bilge water to cover the surface where they
touch (Figure 3-A).
B.For a moderate deadrise angle—If the hull surface is not
smooth, grind it with a disc sander. Place the transducer inside a
thin plastic bag. Partially fill the bag with water and close it tightly
with a cable tie. Wet the surface of the hull and press the active
face of the transducer against it through the bag (Figure 3-B).
C.For any location—If the hull surface is not smooth, grind it with a
disc sander. Coat the active face of the transducer with a water-
®
based lubricant (such as K-Y
jelly). With a twisting motion, press
the face firmly against the hull (Figure 3-C). After testing, wipe all
traces of the lubricant from the transducer’s face.
Observe the echosounder’s performance, and compare it to the
baseline. Look for a stable depth reading that is similar to the
baseline. Compare the thickness and intensity of the bottom trace.
If the performance is close to the baseline, this is a good mounting
location. Remember, some energy is lost transmitting through the
hull. If the test reading differs markedly from the baseline, you will
need to find another location to install the transducer.
NOTE: Fiberglass hull—If there is no reading or it is erratic, the
transducer may be positioned over coring which is absorbing the
acoustic energy. Choose another location. If no other location is
available, check with the boat manufacturer to be certain coring is
present before proceeding with the instructions for “Installation in
a Cored Fiberglass Hull” (page 4).
active face
Figure 2. Establishing a performance baseline
Copyright © 2005 Airmar Technology Cor p. Copyright © 2005 Airmar Technology Corp.
2
AB C
Figure 3. Testing the transducer at the selected location
Page 3
hull
keel
guideline
perpendicular
to keel
base
flange
keel
keel directional
arrow
parallel to
waterline
deadrise
angle
Figure 4. Deadrise angle and guideline
Copyright © 2005 Airmar Technolog y Corp. Copyright © 2005 Airmar Technolog y Corp.
Installation
Cored fiberglass hull—Follow separate instructions on page 4.
CAUTION: The base must be liquid-tight. To ensure a tight bond,
the hull surface under and around the base must be smooth, free
of paint or any other finish, clean, and dry.
CAUTION: The top of the transducer must be level when the
installation is complete.
1. Measure the deadrise angle of the hull at the selected location
using an angle finder (Figure 4). Measure carefully, because the
installed transducer must be within 5° of vertical.
2. The hull surface to be bonded must be smooth and free of paint
or any other finish. If the surface is rough, use a disk sander to
smooth an area 100mm (4") in diameter.
3. To ensure a tight bond, clean and dry both the selected area
and the underside of the base. Remove any dust, grease, or oil
with detergent or a weak solvent such as alcohol.
4. Using a carpenter’s square, draw a line on the hull
perpendicular to the keel through the center of the mounting
keel
directional
arrow
guideline
Figure 5. Aligning the flange of the base
(4°– 12° deadrise angle shown)
location (Figure 5). This will be used as a guideline to orient the
base.
5. The numbers on the flange of the base represent deadrise
angles. Identify the number that most closely corresponds to the
deadrise angle of the hull. Find its match on the opposite side of
the flange. Keeping the keel directional arrows on the side of the
base near the keel, align the two raised marks indicating the
deadrise angle with the guideline drawn on the hull.
6. When you are satisfied that the location of the transducer is
optimal and the orientation of the base corresponds to the
deadrise angle of the boat, apply a generous bead of silicone
sealant to the underside of the flange of the base. (Follow the
sealant manufacturer’s instructions for its use.) Press the flange
firmly in place to form a liquid-tight seal. Allow the sealant to cure.
7. Slide the transducer into the locking ring (Figure 6). Turn the
transducer until the rib that most closely corresponds to the
deadrise angle of the hull is aligned with the angle indicator on
the locking ring. To secure the transducer to the locking ring,
insert the two screws. Do not over tighten the screws.
transducer
locking
ring
10•
deadrise
angle
detail
angle indicator
ribs
Figure 6. Joining the transducer to the locking ring
Copyright © 2005 - 2010 Airmar Technology Corp.
8. Lubricate the O-ring with petroleum jelly. This will help to seal the
assembly and prevent the fill-liquid from leaking. Slide the O-ring
onto the transducer assembly (Figure 7).
front view
transducer
locking
ring
boss (2)
O-ring
NOTE: Lubricate the O-ring with
petroleum jelly before sliding
it onto the transducer assembly.
side view
Figure 7. Installing the O-ring and identifying the bosses
Copyright © 2005 - 2010 Airmar Techno logy Corp.
3
Page 4
NOTE: top of
transducer
is level
transducer
assembly
indicator
keel
angle
base
hull thickness
100mm (4")
transducer
fill with
repair epoxy
or resin
inner skin
core
outer skin
Figure 8. Completed installation is level
Copyright © 2005 Airmar Technology Corp.
9. After the sealant on the base has cured, pour 71 ml (2.4 fl. oz.)
of propylene glycol into the base. Do not over fill. Be sure to
follow the manufacturer’s directions for use.
10.With the angle indicator on the keel side, lock the transducer
assembly into the base (Figure 8). (The bosses on the locking
ring fit into the notches in the base.) Press down and rotate
clockwise until it is seated. When the transducer is installed
correctly, the top will be level. If the deadrise angle is shallow,
the transducer may appear to be level even if it is not. Use a
level to check the installation.
Cable Routing & Connection
CAUTION: If the transducer came with a connector, do not
remove it to ease cable routing. If the cable must be cut and
spliced, use Airmar’s splash-proof Junction Box No. 33-035 and
follow the instructions supplied. Removing the water-proof
connector or cutting the cable, except when using a water-tight
junction box, will void the transducer warranty.
1. Route the cable to the echosounder being careful not to tear the
cable jacket when passing it through the bulkhead and other
parts of the boat. Use grommets to prevent chafing. To reduce
electrical interference, separate the transducer cable from other
electrical wiring and sources of electrical noise. Coil any excess
cable and secure it in place with cable ties to prevent damage.
NOTE: Some transducers are equipped with a short cable,
about 1m (3'), and an extension cable. Be sure to locate the
mated 3-pin connectors well above the bilge waterline. To
facilitate this, use one of the two cable clamps supplied on
either side of the connection.
2. Refer to the instrument owner’s manual to connect the
transducer to the instrument.
Figure 9. Installation in a cored fiberglass hull
Copyright © 2005 Airmar Technolog y Corp.
Installation in a Cored Fiberglass Hull
Installation in a cored hull is difficult. The objective is to bond the
base to the inside surface of the hull’s outer skin while
preventing any moisture from penetrating the core.
CAUTION: There is no way to determine if the outer skin is solid
(no trapped air bubbles in the fiberglass) at the selected location
before cutting the inner skin.
1. Using a 100mm or 4" hole saw, cut through the inner skin and
the core at the selected location (Figure 9). The core material
can be very soft. Apply only light pressure to the hole saw after
cutting through the inner skin to avoid accidentally cutting the
outer hull.
2. Remove the plug of core material, so the inner core of the hull is
fully exposed. Sand the inside surface of the outer skin using a
miniature disk sander. Slightly undercut the surrounding coring
if possible.
3. Clean and dry both the inside surface of the outer skin and the
transducer with a weak solvent, such as alcohol, to remove any
dust, grease, or oil.
4. Place the base in the cavity. Fill the gap between the base and
the hull with repair epoxy or resin following the manufacturer’s
directions for its use.
5. After the repair epoxy or resin has cured, proceed with
“Installation” (page 3).
Replacement Transducer & Parts
The information needed to order a replacement transducer is printed
on the cable tag. Do not remove this tag. When ordering, specify the
part number, date, and frequency in kHz. For convenient reference,
record this information on the top of page one.
Lost, broken, or worn parts should be replaced immediately.
Base & O-ring Kit 33-268-01
Obtain parts from your instrument manufacturer or marine dealer.
Gemeco
Airmar EMEA
USA
Tel: 803-693-0777
email: sales@gemeco.com
Europe, Middle East, Africa
Tel: +33.(0)2.23.52.06.48
email: sales@airmar-emea.com
35 Meadowbrook Drive, Milford, New Hampshire 03055-4613, USA
•
www.airmar.com
4
Copyright © 2005 - 2018 Airmar Technology Corp. All rights reserved.
Loading...