Xylem handylab OX 12 - Manual (Page 50)

What to do if... handylab Ox 12
50 ba75369e04 01/2011
Error message
E7
AR flashes
continuously
Measured value
too low
Measured value
too high
Display
to
Probe symbol
flashes
Cause Remedy
Membrane damaged
– Membrane damaged – Regenerate probe
– Membrane head not screwed
on tight enough
– Screw membrane head tight
Cause Remedy
No stable measured value
– Membrane contaminated – Clean membrane
Cause Remedy
– Insufficient
flow
– Provide flow to the probe
Cause Remedy
– High amount of dissolved
substances
– Correct solubility function using
the salinity equivalent
– Air bubbles bump on the
membrane with high velocity
– Avoid direct flow to the
membrane
– The carbon dioxide pressure
is too high (> 1 bar)
– Measuring not possible
Cause Remedy
– Time-out of the interface – Check the instrument that is
connected
Cause Remedy
– Calibration interval expired – Recalibrate the measuring
system