ATI
Model Q45CT Portable Transmitter
Part 5
– Calibration
29
O&M Manual
Rev-G (7/15)
During the 1-point calibration, the system will automatically pick the correct range
for the calibration reference if the Q45CT is in the
AUTO
range (see Section
5.24). It is recommended to leave the system in
AUTO
mode for this reason. If
the Q45CT is in a manual range, the user must be careful to calibrate with a
solution that falls into the manual range selected. If the calibration solution is
outside the manual range, an error will result. It may be desirable in some cases
to calibrate in a manual range if the conductivity area of interest is close to a
range change point.
Procedure
1. Determine whether the calibration will be done on-line or with the sensor
removed and placed into a reference solution. If the sensor is removed from the
application, rinse and clean.
2. If the sensor has been removed and placed into a solution, allow sensor to
temperature equilibrate with the solution as much as possible. With the sensor
coming from an application that differs greatly in temperature, the user may have
to wait as much as 20 minutes. If the sensor is on-line, the user may want to set
the output HOLD feature prior to calibration to lock out any output fluctuations.
3. Scroll to the CAL menu section using the MENU key and press ENTER or the UP
arrow key.
Cal Cond
will then be displayed.
4. Press the ENTER key and the lower line of the display will prompt the user to
Place the sensor in reference solution
. Press the ENTER key.
5. 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.
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
CalUnstable
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.
