ATI
PQ45P pH System
Part 3
– Sensor Preparation
10
O&M Manual
Rev-B (7/15)
2.4
Flow Control System
The sample flow to the sensors in this instrument is controlled by a special orifice control device
that controls sample flow to approximately 400 cc/min. regardless of variations in inlet pressure.
The flow control device is protected by a y-strainer. This strainer is designed to remove any large
particles that might adversely affect the performance of the flow control.
The y-strainer should be inspected periodically and cleaned of accumulated solids. To do so, it is
easiest to remove the entire flow control system by disconnecting the inlet and outlet tubes from
the top and bottom of the assembly, and then removing it from the mounting clip. Once removed,
use a crescent wrench to unscrew the screen holder. Remove the screen and rinse as needed to
remove any accumulated solids.
2.5
Water Sample Connections
On the hinged side of the case are two quick-disconnect fittings marked INLET and OUTLET.
This is where you will connect your water sample. These connectors contain valves that
automatically close when the mating connector is removed. Mating connectors also contain
valves so that sample lines can be disconnected without closing the main tap valve.
A 20-
foot (6 m.) length of 0.25” O.D. x 0.17” I.D. polyurethane tubing is supplied for connection to
water lines. In addition, tube fittings that mate with either 1/8” NPT or ¼” NPT sample lines are
supplied for convenience.
2.6
Spare Parts
Behind the internal panel in the area of the flowcells and sensors is a molded foam area that
holds spare parts that might be needed in the field. The following items are normally supplied.
Qty. 1
Data Logger Software (if purchased with system)
Qty. 2
Quick-disconnect fittings for sample & drain connection
Qty. 4
Water system adapter fittings
– two each of 1/8” NPT & ¼” NPT
20 feet
¼” O.D. x 0.17” I.D. sample / drain tubing
Attached inside the front cover is a plastic pouch containing the O&M manual for the instrument.
To remove the pH sensor from the flowcell, turn the sensor until the twist-lock pins line up with
the insertion slots and
CAREFULLY
pull the sensor upward. Be very careful removing the
sensor as it is easily broken.
Figure 4 - Standard pH Sensor
