Edgetech 8242XS, Hardware Manual, Page: 25 / 82

3-1
3.0
SETUP AND INSTALLATION
This section contains the information relative to the basic set up and operation of the Model 8242XS
acoustic release. Refer to the specific information sheet that shipped with the unit, for details of its specific
equipment. This sheet includes the 8242XS’s commands, and transponder frequencies.
Acoustic
Efforts should be made to ensure that there is a clear acoustic path between the 8242XS Transducer and
the source (typically a dunking Transducer from a deck unit). Structural elements of a mooring system
which have significantly different acoustic impedance than that of seawater will cause absorption or
reflection of acoustic signals, which will degrade the operation of the unit. Floatation, including glass
spheres, syntactic foam and plastic floats are particularly problematic. Floats placed physically close to
the Transducer can create a blind area in the Transducers beam pattern.
Mechanical
The Release Load is held through the Lifting Support, and Release Hook. There are isolation shoulder
washers on the top pad eye to prevent electrical contact with the mooring. In some installations (such as
a trawl resistant Benthic Landers) the unit needs to be secured to the structure. It is important to verify
that the Release Hook is not obstructed in its motion, which could prevent it from disengaging.
The release mechanism is designed for in-line loads; side loading will severely degrade performance.
Generally, the Release Link is treated as a disposable item. It is used to electrically isolate the release from
the rest of the mooring.
Status Reply
Upon receiving a valid command, the instrument will return a series of pings which are an indication of
the status of the tilt and release sense switches.
The 8242XS is equipped with sensors that monitor the tilted or not tilted orientation of the system. This
information allows the unit to send a coded status reply, based on the instruments orientation and release
state. The tilt status is useful for ascertaining whether the mooring or platform that has been deployed
has landed as planned. At the end of a deployment, the information is useful in determining whether
forces such as strong currents or trawl activity have affected the mooring or platform.
The tilt sensor is a 45° mechanical switch that is mounted on the Release Circuit Board assembly. In the
standard instrument configuration, with the release mechanism down, the unit is defined as “not tilted”.
For applications requiring a narrower maximum allowable angle of tilt optional tilt switches are
available. The switch can also be installed at different angles to change the standard orientation.