ATI
Model A15/82 Fluoride Monitor with Auto-Calibration
21
O&M Manual
Rev-G (6/10)
CHEMISTRY MODULE STARTUP
After mechanical and electrical installation is complete, the system is ready for operation. The chemistry
module should be placed in operation first. The electronics do not need to be powered during chemistry module
startup, but can be powered if desired. No harm will result provided that relays or outputs are not being used for
control.
SENSOR INSTALLATION
Before applying power to the chemistry module, the combination fluoride/reference electrode must be
installed. The electrode is shipped dry in the electrode box. The fluoride electrode box contains a polishing strip
which must be saved for ongoing maintenance. Keep the polishing strip where it will not be lost.
As shipped, the fluoride electrode does not contain reference filling solution. The solution is supplied in a
separate bottle along with a plastic dropper used to fill the electrode. Near the top of the electrode is a black
plastic sleeve that covers the fill port. Pull the sleeve down so the fill hole is accessible and fill the reference
chamber with electrolyte using the plastic dropper. Push the sleeve back up over the fill hole and the sensor is
ready for use.
The fluoride electrode slides into the flow block on the front of the chemistry module. The fluoride
sensor should be kept dry with the protective cover in place until it is time to put the analyzer into permanent
service. The cable for connection to the monitor is already installed. The cable screws onto the back of the
fluoride sensor and connects the sensor directly to the monitor. This is a high impedence signal, and this cable
cannot be spliced.
FLOW STARTUP
After the electrode is installed, check that the inlet tubing and drain connections to the inlet chamber are
complete and that the drain tubing is connected to a permanent drain. See Figure 5 for piping details. Turn on
the inlet sample flow using the flow control valve installed on the sample line. Adjust the flow so that water is
overflowing from the inlet chamber into the drain chamber. The rate at which water overflows this chamber will
determine the response time of the monitor. Keeping the overflow running at about 200 cc/min. will provide good
sample exchange. The inlet flow can be adjusted to a lower rate if desired, but this will increase the sample
transport time to the pickup tube for the analyzer.
When flow has been established at the inlet chamber, place the sample pickup tube into the inlet
chamber and place the drain tube into the drain chamber. Check to see that the buffer container is mounted,
that buffer solution is in place, and that the buffer pickup tubing is connected. When these items are checked,
power can be applied to the chemistry module. Note that the fuse assembly inside the chemistry module can be
used to turn power on and off. Open the rear compartments of the chemistry module and pull the fuse holder out
to disconnect power.
When power is applied, the two pumps will activate. Sample will be pulled out of the overflow chamber
through 1/16” ID tubing which is routed through the top section of the pinch valve. Buffer will be metered into a
“T” fitting prior to the sensor flow block to adjust the sample to optimum conditions for measurement. The
measured sample will exit the side of the sensor flow block and drain by gravity into the drain side of the
overflow assembly below. It is recommended that you verify that buffer is being delivered to the mixing tee at
startup. To do this, remove the sample pickup tube from the overflow chamber inlet so that no sample is being
pumped. Then disconnect the buffer tube from the mixing tee and allow the chemistry module to run for about
10 minutes. You should see small droplets of buffer coming out of the buffer delivery tube (use a paper towel to
catch the droplets as they drip from the tube). After verifying that buffer is flowing, connect the tube to the tee
and put the sample pickup tube into the overflow inlet. At this point, sample should begin to pump into the
system.
