Hach pHD Sensor User Manual page 13

3. Push the MENU key and select Sensor Setup, Calibrate, pH.
4. Select the type of calibration:
Option
2 POINT
BUFFER
1 POINT
BUFFER
2 POINT
SAMPLE
1 POINT
SAMPLE
5. If the passcode is enabled in the security menu for the controller, enter the passcode.
6. Select the option for the output signal during calibration:
Option Description
ACTIVE The instrument sends the current measured output value during the calibration procedure.
HOLD The sensor output value is held at the current measured value during the calibration procedure.
TRANSFER A preset output value is sent during calibration. Refer to the controller user manual to change
the preset value.
7. With the sensor in the first reference solution or sample, push ENTER.
The measured pH and temperature value is shown.
8. Wait for the value to stabilize and push ENTER
9. If using a sample, measure the pH value with a secondary verification instrument. Use the arrow
keys to enter the measured value and push ENTER.
Note: If a pH buffer not listed in the Cal Options menu is used, refer to the buffer bottle to find the pH value that
corresponds to the temperature of the buffer.
10. For a 2-point calibration:
a. If using a reference solution, remove the sensor from the first solution and rinse with clean
water.
b. Put the sensor in the next reference solution or sample and push ENTER.
The measured pH and temperature value is shown.
c. Wait for the value to stabilize. Push ENTER
d. If the solution is a sample, measure the pH value with a secondary verification instrument.
Use the arrow keys to enter the measured value and push ENTER.
Note: If a pH buffer not listed in the Cal Options menu is used, refer to the buffer bottle to find the pH value
that corresponds to the temperature of the buffer.
11. 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. Repeat the calibration with
fresh reference or sample solution. Refer to
information.
12. If the calibration passed, push ENTER to continue.
1
If the option for Auto Stab (auto stabilization) is set to Yes in the Calibration Options menu, the
screen will advance to the next step automatically. Refer to
on page 14.
Description
Use 2 buffers for calibration, for example pH 7 and pH 4 (recommended method). The
buffers must be from the buffer set that is specified in the Cal Options menu (refer to
Change the calibration options
Use 1 buffer for calibration, for example pH 7. The buffer must be from the buffer set that
is specified in the Cal Options menu (refer to
on page 14).
Use 2 samples of known pH value for calibration. Determine the pH value of samples with
a different instrument.
Use 1 sample of known pH value for calibration. Determine the pH value of sample with a
different instrument.
on page 14).
Change the calibration options
1
.
1
.
Troubleshooting on page 16 for more
Change the calibration options
English 13