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MODEL SOLU COMP II
SECTION 8.0
TROUBLESHOOTING
8.2.4 RTD Sense Line for Sensor 1 or Sensor 2 is Open.
The Solu Comp II measures temperature using a three-wire RTD inside the sensor. See Figure 8-3. The in and
return leads connect the RTD to the measuring circuit in the analyzer. A third wire, called the sense line, is con-
nected to the return line. The sense line allows the analyzer to correct for the resistance of the in and return leads
and to correct for changes in lead wire resistance with temperature.
A. Verify that all wiring connections are secure.
B. The analyzer can be operated with the sense line open. The measurement will be less accurate because the
analyzer can no longer correct for lead wire resistance and for changes in lead wire resistance with ambient
temperature. However, if the sensor is to be used at approximately constant temperature, the lead wire resist-
ance error can be eliminated by calibrating the sensor at the measurement temperature. Errors caused by
changes in lead wire resistance with changes in ambient temperature cannot be eliminated.To make the error
message disappear, connect the RTD sense and return terminals with a jumper.
8.2.5 EEPROM Failure.
Call the factory at (800) 854-8257.
8.3 TROUBLESHOOTING WHEN NO ERROR MESSAGE IS SHOWING.
Problem
See Section
New temperature during calibration more than 2-3°C different from the live reading
8.3.1
Calibration Error warning during two-point calibration
8.3.2
Calibration Error warning during standardization
8.3.3
Invalid Input while manually entering slope
8.3.4
Sensor does not respond to known pH changes
8.3.5
Calibration was successful, but process pH is slightly different from expected value
8.3.6
Calibration was successful, but process pH is grossly wrong and/or noisy
8.3.7
Current output too low
8.3.8
Alarm relays do not operate when alarm setpoint is exceeded
8.3.9
Display is unreadable -- too faint or all pixels dark
8.3.10
8.3.1 Difference Between Solu Comp II and Standard Thermometer is Greater Than 3°C.
If an error message appears during a temperature calibration, check the following:
A. Is the standard thermometer, RTD, or thermistor accurate? General purpose liquid-in-glass thermometers, par-
ticularly ones that have been mistreated, can have surprisingly large errors.
B. Is the temperature element in the pH sensor completely submerged in the test liquid?
C. Is the standard temperature sensor submerged to the correct level?
D. Review Section 6.2.2.
