YOKOGAWA PH71, User Manual

Page: 62 / 100

IM 12B03D01-01E
7-5
7. Troubleshooting
(5) Err5 Out of temperature measuring range
Appears during measurement.
With the Model PH71 Personal pH Meter, a general-purpose sensor can be used in the
temperature range of 0 to 80
8
C and a needle type or test tube size sensor in the
temperature range of 0 to 100
8
C. If the operating temperature is significantly outside this
measuring range (below -10.0
8
C or above 120
8
C), an Err5 message will appear.
Possible Cause:
• Operating temperature is significantly outside the measuring range.
Corrective Action:
• Adjust the temperature of the solution so it falls within the measuring range (0 to
80
8
C for general purpose types and 0 to 100
8
C for needle type or test tube size
sensor).
(6) Err6 Meter electronics failure
Possible Cause:
• Failure of electronics.
Corrective Action:
• Contact your nearest Yokogawa sales office.
7.3 Causes of Abnormal Measured Values
If error messages do not occur, but measured values seem incorrect, check the following:
• Are proper standard solutions used?
• Is the sensor connected to the meter securely?
• Are air bubbles trapped in the electrode tip?
• Has the electrode dried out?
• Is the electrode dirty?
• Is the sensor damaged or dirty?
• Is the electrode immersed in the sample solution properly?
• Has the level of the electrode filling solution dropped (for KCl refillable type
sensors)?
• Is the electrode filling solution contaminated with the sample solution (for KCl
refillable type sensors)?
• Has the actual temperature of the solution been set properly (for a needle type or
test tube size pH sensor)?