Hach 8350.3 Benutzerhandbuch Seite 16

Section 6 Troubleshooting
6.1 Intermittent data
During calibration, data is not sent to the datalog. Thus, the datalog can have areas where the data is
intermittent.
6.2 Test the pH sensor
Pre-requisites: Two pH buffers and a multimeter.
If a calibration fails, first complete the maintenance procedures in .
1. Put the sensor in a pH 7 buffer solution and wait for the temperature of the sensor and buffer to
reach room temperature.
2. Disconnect the red and white wires from the module.
3. Measure the resistance between the red and white wires to verify the operation of the
temperature element.
• PT1000 temperature element—The resistance should be 1090–1105 Ω at approximately 25 °C
(77 °F).
• PT100 temperature element—The resistance should be approximately 109 Ω at approximately
25 °C (77 °F).
4. If the temperature element is good, reconnect the wires to the module.
5. Select the main menu icon, then select Devices. A list of all of the available devices shows.
6. Select the device and select Device menu > Diagnostics/Test.
7. Select Sensor signals. For a standard pH electrode, the reading should be between –50 and
+50 mV.
8. Rinse the sensor with water and put it in a pH 4 or pH 10 buffer solution (use only a pH 4 buffer
solution for antimony sensors). Wait for the temperature of the sensor and buffer to be at room
temperature.
9. Compare the mV reading in the pH 4 or 10 buffer to the reading in the pH 7 buffer. For a standard
pH electrode, the reading should differ by approximately 160 mV. If the difference is less than
160 mV, call technical support.
6.3 Diagnostics/Test menu
The Diagnostics/Test menu shows current and historical information about the sensor. Refer to
Table 2. Push the main menu icon, then select Devices. Select the device and select Device menu
> Diagnostics/Test.
Option
Module information
Sensor information
Last calibration
Calibration history
Reset calibration history For service use only
Impedance status
Sensor signals
16 English
Table 2 Diagnostics/Test menu
Description
Shows information about the sensor module.
Shows the sensor name and the serial number entered by the user.
Shows the number of days since the last calibration was done.
Shows a list of all calibrations by date/time stamp. Use the arrows keys to select a
calibration, then push OK to show the details.
For pH sensors only—Refer to
sensors only) on page 14.
Shows the current reading in mV.
If Impedance status is set to Enabled, shows the active and reference electrode
impedances.
Impedance measurements (glass electrode pH