Xylem 6-Series Multiparameter - Manual (Page 358)

ROX Optical DO Sensor Appendix M
YSI Incorporated Environmental Monitoring Systems Operations Manual M- 9
protocol will prevent the stiff EDS auxiliary brush which cleans the pH or pH/ORP sensor from abrading
the outer paint layer of the ROX membrane. There should be no problem with the EDS wiper parking
correctly even though it is white (rather than the standard black wiper supplied with the probe) since an
internal Hall Effect device controls the parking in the ROX sensor.
How can I tell if my ROX sensor is not functioning is not functioning properly?
There are two factors which would indicate that your sensor is not operating up to specifications. The first
is that you are observing software errors when you attempt to calibrate the ROX probe. The second is that
your data (either in Discrete Sample or Unattended Sample studies becomes jumpier than normal. In
addition, if your membrane surface has suffered major damage as evidenced by loss of more than 10% of
the outer paint layer, then, even if the readings are stable and you do not see calibration errors, it is
probably time to change your membrane assembly.
What should I do if I don’t think that my ROX sensor is functioning properly?
The first step is to remove the membrane assembly from the probe face as shown in Section 2.10.2 of this
manual and make certain that there is no moisture present under the membrane assembly. If moisture is
present, gently remove it with lens cleaning tissue and, if possible, by a compressed air stream. Make
certain that the O-ring which seals the membrane assembly to the probe face is in the groove and
undamaged. Then replace the membrane assembly and evaluate the probe performance. If the
performance has not improved, consult YSI Technical Support for advice on how to proceed next.