Hach Chlorine Sensor, User Manual

Page: 15 / 442

7. If Chemical was selected:
a. Turn off the process flow and put water with no chlorine through
the flow cell. Make sure the temperature of the water with no
chlorine is as close as possible to the process sample flow
temperature.
b. Push ENTER .
The measured value is shown.
c. Wait for the value to stabilize and push ENTER
5
to set the zero-
point chemically.
d. Turn off the flow of water with no chlorine and turn on the process
flow.
e. Push ENTER .
The measured value is shown.
f. Wait for the value to stabilize and push ENTER
5
to enter a
process flow measurement.
8. Measure the chlorine concentration of the process flow (grab sample
analysis) with an instrument using a reference method (e.g., DPD).
Use the arrow keys to enter the measured value and push
ENTER .
9. Review the calibration result:
• Passed—the sensor is calibrated and ready to measure samples.
The slope and/or offset values are shown.
• Failed—the calibration slope or offset is outside of accepted limits.
Do sensor maintenance (refer to Maintenance on page 16) and
then repeat the calibration.
10. If the calibration passed, push ENTER to continue.
11. If the option for operator ID is set to Yes in the Calibration Options
menu, enter an operator ID. Refer to
Change the calibration options
on page 15.
12. On the New Sensor screen, select whether the sensor is new:
Option Description
YES The sensor was not calibrated previously with this instrument. The
days of operation and previous calibration curves for the sensor are
reset.
NO The sensor was calibrated previously with this instrument.
13. Return the sensor to the process and push ENTER .
The output signal returns to the active state and the measured
sample value is shown on the measure screen.
Note: If the output mode is set to hold or transfer, select the delay time when
the outputs return to the active state.
Reset calibration to defaults
To remove a bad calibration, replace the user calibration settings with
the default calibration settings using the Calibrate menu. Then
recalibrate the sensor when needed.
1. Push the MENU key and select Sensor Setup, Calibrate, [Select
Sensor], Reset Defaults.
2. If the passcode is enabled in the security menu for the controller,
enter the passcode.
3. Select Yes and push Enter .
Change the calibration options
The user can set a calibration reminder, enable auto stabilization during
calibrations or include an operator ID with calibration data from the Cal
Options menu.
1. Push the MENU key and select Sensor Setup, Calibrate, [Select
Sensor], Cal Options.
2. Customize the options:
Option Description
AUTO STAB Enables the system to accept measurement signal values
during calibrations and advance to the next step of the
calibration when the system determines the measurement
signal has stabilized-On or Off (default). Enter a
stabilization range-25 to 75 ppb (0.025 to 0.075 ppm).
CAL REMINDER Sets a reminder for the next calibration in days, months or
years.
OP ID ON CAL Includes an operator ID with calibration data—Yes or No
(default). The ID is entered during the calibration.
English 15