Temperature Measurement And Calibration Problems - Emerson Rosemount Analytical HART 5081-A-HT Instruction Manual

MODEL 5081-A
16.2.14 AdC
AdC means the analog to digital converter has failed.
1. Verify that sensor wiring is correct and connections are tight. Be sure to check connections at the junction box if one
is being used. See Section 3.0.
2. Disconnect sensor(s) and simulate temperature and sensor input.
To simulate
Dissolved oxygen
Ozone or chlorine
pH
Temperature
3. If the transmitter does not respond to simulated signals, the analog PCB has probably failed. Call the factory for assis-
tance.
16.2.15 bAd Gnd
bAd Gnd usually means a problem with the analog PCB. Call the factory for assistance.
16.2.16 In too biG
In too biG means the raw millivolt signal from the pH sensor is too large.
1. Verify that sensor wiring is correct and connections are tight. Be sure to check connections at the junction box if one
is being used. See section 3.0.
2. Replace the pH sensor with a sensor known to be working.
3. If replacing the pH sensor does not cause the message to disappear, call the factory for assistance.
16.2.17 RitE Err
Program settings in the 5081-A can be protected against accidental changes by setting a three-digit security code. Settings
can further be protected by removing a jumper (JP-1) from the CPU board. If JP-1 has been removed program, settings
cannot be changed.

16.3 TEMPERATURE MEASUREMENT AND CALIBRATION PROBLEMS

16.3.1 Temperature measured by standard was more than 1°C different from transmitter.
1. Is the standard thermometer, RTD, or thermistor accurate? General purpose liquid-in-glass thermometers, particular-
ly ones that have been mistreated can have surprisingly large errors.
2. Is the temperature element in the sensor completely submerged in the liquid?
3. Is the standard temperature sensor submerged to the correct level?
See Section
16.9
16.10
16.11
16.12
SECTION 16.0
TROUBLESHOOTING
81