Specifications

3. Operation MI 611-211 – October 2005
15
Diagnostics
(Refer to “Structure Diagram 11” on page 48.)
The Diagnostics mode enables you to perform checks on your system at any point in time. While
you are in the Diagnostic mode, two segments of the bar graph will appear under the legend
DIAG at the top of the front panel. To enter the Diagnostics mode, press the DIAG key on the
front panel. If there are no errors, your display will read
DIAGS OK. If there was an error flagged
as XMTR ER, PROBE ER, or CONFIG ER in the Measurement mode, the Diagnostics mode
will help you further identify the specific error and corrective action. Possible errors and the
recommended corrective actions are listed in Table 4.
Table 4. Diagnostic Error Messages
Message Description Corrective Action
Transmitter Error
Probe Errors
GLASS Resistance of glass electrode is checked versus solution
ground. Error is flagged if resistance is less than user set
limit.
Replace electrode
LOWSLOPE Flags an error after a 2-point calibration in buffers
when the Nernst slope of the sensor becomes less than
the user set limit.
Replace electrode or
solution
COAT Checks reference junction resistance against solution
ground. Error is flagged if resistance is greater than user
set limit.
Clean electrode
Sensor is not immersed in solution. Check that solution ground
and reference junction are
immersed in solution.
LEAKAGE Checks solution leakage into the probe by checking
resistance between solution ground and the RTD.
Error is flagged if resistance is anything but infinite.
Replace
PREAMP Checks preamplifier by monitoring voltage coming out
of it. Error is flagged at voltage greater than 2 volts.
Replace
AGING Flags an error after a 2-point calibration in pH buffers
when the Nernst slope of the sensor has decreased
sequentially five times.
See Note below
ATCSHORT
ATC OPEN
Flags an error if the resistance of the temperature
compensator is greater or less than the expected
resistance of the device configured.
Replace temperature
compensator