Manning YB8, Operating And Instruction Manual

Page: 120 / 121

10
The sampler uses a peristaltic pump the draw the fluid being sampled into the collection
bottle(s). The peristaltic pump produces suction to draw the sample and purges the intake line by
squeezing sections of the pump tubing against the inside wall of the pump body using a rotating arbor
with two rollers.
The sampler controller includes the processor circuit board, display, and keypad. It provides the
logic and processing circuitry to operate the peristaltic pump and associated sampler hardware. It also
processes external inputs to the sampler (i.e., contact closure, pulse, or optional 4-20mA input)
The peristaltic pump is mounted to the right side of the yellow controller housing. The black
pump body, arbor assembly, and clear lid are visible from the outside. The pump motor, RPM sensor,
and associated hardware are mounted inside of the housing.
AC line power (110VAC 60Hz or 220VAC 50Hz) is converted to 12VDC by a power supply
located inside of the sampler controller housing. 12VDC is used to power the rest of the sampler
electronics (the refrigerator runs directly off the AC line power).
The pump motor receives power from the controller to turn the arbor using a belt drive. The
pump rotates in a Counter-clockwise direction (as viewed from the top of the pump) to purge the fluid
line and in a Clockwise direction to draw fluid.
The pump also contains an RPM sensor consisting of a slotted disk (mounted directly to the arbor
shaft) and optical sensor. The RPM sensor sends pulses to the controller when the pump is rotated.
Each pulse represents 1/16
th
of pump revolution. The RPM sensor pulses are used to measure the
amount of fluid being deposited into the sample collection bottle(s). The sampler controller also records
the pump revolutions to provide a warning to the operator that the pump tubing is wearing and may need
to be replaced. A secondary purpose of the RPM sensor is to provide feedback to the controller that the
pump is actually turning. If the sampler received no signal from the RPM sensor when the pump should
be turning, the controller turns power to the pump motor off to prevent further damage, and displays a
RPM SENSOR FAIL
message.
The pump is equipped with a safety kill switch to keep the pump from operating without the lid
installed. A magnetic reed switch located in the pump body sends a signal to the controller if the pump
lid is not installed. The pump lid has a magnet located in it that opens the reed switch when the lid is
attached. If the lid is not installed, the switch is closed and the controller will stop the pump from
running and display a
PUMP COVER OPEN
message.
Located on the intake side of the sampler pump tubing just before the pump is a fluid sensor,
which detects the presence of fluid in the intake line. The controller uses this information to rinse the
sampler intake line and to draw the actual sample. The fluid sensor is either a continuity type or an
ultrasonic type.
For single bottle samplers, the bottle full sensor located on the discharge tube signals the
controller that the bottle is full. This is a continuity probe type of sensor. When the controller senses
that the bottle is full, samples are no longer taken.
For multi-bottle samplers, the controller supplies power to the distribution assembly’s stepper
motor for rotating the spout from bottle to bottle. The spout is advanced (stepped) in a Clockwise
direction. Each motor step moves the spout 15 degrees, or one bottle location for a 24-bottle system
(360 divided by 24 equals 15).
The sample cycle starts by first purging the intake line to clear it of any residual fluid. If rinses
are programmed, the sampler draws fluid up to the fluid sensor and then purges the line. This is