Emerson Rosemount5081, Instruction Manual, Page: 105 / 152

Message Explanation See section
bAd rtd Bad temperature reading bAd rtd, TEMP HI, TEMP LO, and
rtd OPEn
TEMP HI Temperature reading exceeds 150 °C (302 °F) bAd rtd, TEMP HI, TEMP LO, and
rtd OPEn
TEMP LO Temperature reading is less than -15 °C (5 °F) bAd rtd, TEMP HI, TEMP LO, and
rtd OPEn
rtd OPEn RTD or thermistor is open bAd rtd, TEMP HI, TEMP LO, and
rtd OPEn
SenSE OPEn Sense line is not connected SenSE OPEn
PH in Raw millivolt reading from pH sensor is too
large pH In
SLOPE HI pH sensor slope exceeds 62 mV/pH SLOPE HI or SLOPE LO
SLOPE LO pH sensor slope is less than 40 mV/pH SLOPE HI or SLOPE LO
-0- OFFSEt Zero offset during standardization exceeds
programmed limit -0- OFFSEt
GLASSFAIL Measured glass impedance is less than pro-
grammed limit GLASSFAIL
FACt FAIL Unit has not been factory calibrated FACt FAIL error message
CPU FAIL Internal CPU tests have failed 9.4.2.13
ROM FAIL Internal memory has failed 9.4.2.13
AdC Analog to digital conversion failed AdC
bAd Gnd Bad ground bAd Gnd
In too biG mV signal from pH sensor is too large In too biG
RitE Err CPU PCB jumper (JP-1) has been removed RitE Err
bAd SEnSor
Bad sensor means that the sensor current is a large negative number.
bAd SEnSor may appear for a while when the sensor is first placed in service. Observe the
sensor current (go to SEnSor Cur under the Diagnostic menu). If the sensor current is
moving in the positive direction, there is probably nothing wrong, and the error message
should soon disappear.
Procedure
1. Verify that wiring is correct. Pay particular attention to the anode and cathode
connections.
2. Verify that the transmitter is configured for the correct measurement.
Configuring the measurement sets (among other things) the polarizing voltage.
Applying the wrong polarizing voltage to the sensor can cause a negative current.
3. Replace the sensor membrane and electrolyte solution and clean the cathode if
necessary.
Diagnostics and troubleshooting
Instruction Manual 95