Scraper Clearance
In certain applications such as those where the ASLD 2200 is installed on a fixed bridge above
a moving scraper it is necessary to bring the sensor above the water surface to prevent damage
to the sensor.
The ASLD 2200 allows the user to instruct the sensor to rise to 100% to allow the scraper to
pass and then return to the tank to continue measurement.
It is recommended that the installer consult Partech before starting installation to ensure that the
correct measures are taken to prevent damage to either instrument or to the scraper mechanism.
Under normal circumstance it is possible to place a detector ahead of the bridge that will
provide the ‘up’ command and another sensor after the bridge that will provide the ‘down’
command.
These external sensors can be wired in parallel to the up and down button on the outside of the
enclosure using terminals 1 to 3.
Bridge Clearance Control
Associated with the scraper clearance function is the Bridge Clearance adjustment, this allows
the sensor to come clear of the water to allow the scraper to pass. To adjust use the following
steps:
Raise the sensor to the surface using the rotary switch.
Select ‘motor off’
Turn off power
Set Links C and D to the right hand position and switch on
Select ‘motor up’ and turn the bridge clearance control clockwise until the sensor is raised far
enough to allow the scraper to pass. This can be set to a maximum of 110%.
Return the unit to ‘automatic’ and press down to return to measurement.
If power is temporarily lost the sensor will rise to the surface on power up and remain there
until the scraper passes after which it will return to automatic measurement.
Controls and Settings
Page 13
