ATI
Q46UV UV254/Turbidity Monitor
Part 6 - Calibration
41
O&M Manual
Rev-D (11/19)
5.
Press the Enter key and the message “Wait” will flash. Note that the message will flash for 3-
4 minutes while the sensor makes all of its internal adjustments. If the zero offset is too high,
a “Cal Fail” message will appear and the “Fail” icon on the display will light up.
6. Once the zero adjustment is complete, pull the syringe plunger back again to suck out the
distilled water or simply move the valve to the normal operate position and allow the standard
to flow to drain. If the outlet tube was disconnected, be sure to reconnect prior to turning on
flow. At this point, a span check or calibration can be done if desired.
6.12 Cal UVA Span
Prior to attempting a span calibration, it is best to remove the sensor from the flowcell and wipe
the optical surfaces with a soft cloth to remove any buildup that could affect sensor performance.
After the sensor is clean, put it back into the flowcell. If necessary, also clean the inside of the
flowcell. Proceed as follows.
1. Refer to Figure 9 on page 16. The 3-way valve supplied with the flowcell provides a
convenient port for draining the flowcell and introducing a calibration standard into the
flo
wcell. As part of the system, a 60 cc syringe and 18” of silicon tubing is provided for use in
feeding standard into the flowcell.
2. Prior to feeding span solution, the flowcell must be drained. Turn the yellow valve handle so
that the OFF position is facing the sample inlet tube. This will stop sample flow and open the
side port. Allow water from the flowcell to drain out this port. Note that you may need to
disconnect the outlet tube for water to flow out of the open port.
3. With the syringe is a short length of tubing and a luer fitting that mates with the end of the
syringe. Place the end of the tube into a bottle of UVA standard solution. UVA standard may
be a third party solution or it may be the KHP solution supplied with the system. Pull the
plunger back to fill the syringe with 40-50 cc. Connect to the open side of the 3-way valve
and depress the plunger to fill the flowcell.
4. Allow the sensor to sit in the UVA standard for 5 minutes to get a stable reading. Once a
stable reading is di
splayed, press the Menu key to get to the CAL menu. Use the ▲ key to
access “Cal UVA”.
5. Press Enter and you will be prompted to enter the value of the standard you are using for
calibration. Enter either the value of your third party standard or the value from your ATI
calibration solution. Use the
▲ key to adjust the flashing digit and the ◄ key to move to the
next digit.
6.
Press the Enter key and the message “Wait” will flash. Note that the message will flash for 3-
4 minutes while the sensor makes all of its internal adjustments. If the sensor is not able to
adjust to the value entered,
a “Cal Fail” message will appear and the “Fail” icon on the display
will light up.
7. Once the span adjustment is complete, pull the syringe plunger back again to suck out the
standard or simply move the valve to the normal operate position and allow the standard to
flow to drain. If the outlet tube was disconnected, be sure to reconnect prior to turning on
flow.
