YOKOGAWA PH71, User Manual

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IM 12B03D01-01E
7-2
7. Troubleshooting
7.2 Error Messages, Possible Causes, and Corrective Actions
Table 7.1 Error Message
T0701.EPS
Error Message*
1
Err1
Err2
Err3
Err4
Err5
Err6
Description
Unstable input emf
Abnormal asymmetry potential
Abnormal slope or calibration temperature
Out of measuring range
Out of temperature measuring range
Meter electronics failure
Occurrence
During calibration
During measurement
*1: For displayed digital characters, see Alphanumeric Display Table in Preface.
(1) Err1 Unstable input emf
Appears during calibration.
A calibration result is accepted when the variation of input emf for 10 seconds falls
within
6
1 mV (approximately
6
0.02 pH equivalent). If the variation for 10 seconds
cannot stabilize and is outside the range of
6
1 mV even after 3 minutes has elapsed in
calibration, an Err1 message will appear.
Possible Causes:
• Dry electrode.
• Clogged liquid junction.
• Insulation failure in electronics.
• Sensor immersed improperly.
Corrective Actions:
• Leave the sensor in a standard solution until the reading stabilizes, and then try
recalibration.
• Remove dirt or deposits from the liquid junction. (See Section 6.2.)
• Remove stain or moisture from the connectors. (See Section 6.6.)
• Immerse the sensor properly (See Section 3.2.)
• Immerse the sensor in water for 1 to 2 hours or longer to rehydrate. (See Section
6.4.)