ATI
Q46C2 2Electode Conductivity System
Part 8
– Calibration
44
O&M Manual
Rev-H (6/19)
6.
The system now begins acquiring data for the calibration value. As data is gathered, the
units for conductivity and temperature may flash. Flashing units indicate that this
parameter is unstable. The calibration data point acquisition will stop only when the data
remains stable for a pre-determined amount of time. This can be overridden by pressing
ENTER. If the data remains unstable for 10 minutes, the calibration will fail and the
message
Cal
Unstable
will be displayed.
7.
The screen will display the last measured conductivity value and a message will be
displayed prompting the user for the lab value. The user must then modify the screen value
with the arrow keys and press ENTER. The system then performs the proper checks.
8.
If accepted, the screen will display the message
PASS
with the cell constant value, and
then it will return to the main measurement display. If the calibration fails, a message
indicating the cause of the failure will be displayed and the FAIL icon will be turned on.
9.
If this is a first-time installation or the sensor has just been replaced, also perform a zero-
cal as described in Section 7.4.
8.3
Performing a Cell Constant Calibration
The Cell Constant calibration method utilizes a factory measured cell constant for the sensor. No
solutions are required for a cell factor calibration.
The cell constant represents the physical electrode characteristics of the sensor. The surface area
of the electrodes, the spacing of the electrodes and the sensor cable all contribute to cell constant
of the sensor. By entering the factory cell value labeled on the sensor cable, the Q46C2 adjusts
the factory calibration to match the characteristics of the specific sensor being used.
The cell constant value may be entered at any time, and it is not necessary to move or prepare the
sensor in any way. Once this number is entered, the system is ready to use. Note that if the sensor
cable length is adjusted (cut or extended) the cell constant data on the sensor label may be
inaccurate for calibration. At this point, the 1-point calibration should be used.
Procedure
1.
Scroll to the CAL menu section using the MENU key and press ENTER or the UP arrow
key. Press the UP arrow key until
Cell Const
is displayed.
2.
Press the ENTER key. The screen will display a flashing value for the cell factor. Using
the arrow keys, enter the cell factor number from the label on the sensor and press ENTER.
Ranges of acceptable values are 0350 - 0650 (0.05 cell), 3500 - 6500 (0.5 cell) and 0667
- 1330 (1.0 cell).
3.
If this is first-time installation or the sensor has just been replaced, also perform a zero-cal
as described in Section 8.4.
