Michell Instruments Liquidew EExd, User Manual

Page: 39 / 90

Liquidew EExd User’s Manual
Michell Instruments 31
MAINTENANCE
4.4 Troubleshooting
4.4.1 Error Messages
If a system errors occur, an error message will appear at the bottom line of the MAIN
Page describing the problem. If more than one system error has occurred, the error
messages associated with those faults will continually scroll in turn.
TEMPERATURE OUT OF RANGE
DEWPOINT
3.9
0
Cdp
TEMPERATURE
55.4
0
C
Figure 26
Error Message Line
Error Message Description and Possible Causes
DEWPOINT UNDER RANGE Dew point <-120°C (<-184°F) or sensor tile failure
DEWPOINT OVER RANGE Dew point >+30°C (>+86°F) or sensor tile failure
TEMPERATURE OUT OF
RANGE
Temperature >+50 or <0°C (>+122 or <32°F)
LOW FLOW
Flow through sensor measurement cell is <0.1 l/min
(0.03 GPM) or flow meter has failed / disconnected
HIGH FLOW
Flow through sensor measurement cell is >2.6 l/min
(0.69 GPM)
SATURATION Dew point is greater than or equal to temperature
CAL TABLE ERROR Fault with sensor calibration data
INTERNAL HEATER FAULT
Internal temperature set-point not achievable or fault
with the internal temperature control devices
4.4.2 Error Messages Flashing over Displayed Values
A short message will flash over the displayed value in the MAIN Page, in certain
conditions, as indicated below:
Flashing Message Over Value Condition
error
Dew-point or
moisture content
Moisture saturation condition (dew point ≥
temperature)
error
Dew-point or
moisture content
Calibration table error (checks sensor
impedance values are increasing in the
correct direction)
under
Dew-point or
moisture content Dew point under range <-120°C (<-184°F)
over
Dew-point or
moisture content Dew point over range >+30°C (>+86°F)
error Temperature
Sensor temperature fault <-40 or >+70°C
(<-40 or >+158°F)