Oxygen Sensor - Hach ORBISPHERE Manual Básico Del Usuario

27. If not using a protection cap with grille proceed to step 28. Otherwise, take a new Dacron
patch from the box of O-rings in the recharge kit. Place the mesh in the center of the protection
cap. It is very important that the mesh is in the center of the protection cap and covering the
entire grille. Lower the sensor onto the protection cap making sure not to disturb the mesh.
28. Push the protection cap firmly into place, making sure one of the four slots in the protection cap
fits over the small locking pin (highlighted right). If it is necessary to turn the protection cap to fit
over the locking pin, ensure you only turn it clockwise to avoid unscrewing the cartridge.
29. Finally, screw the protection cap locking washer back into place in a clockwise motion, and
tighten finger tight.
Troubleshooting

Oxygen sensor

Problem
Sensor won't calibrate, even after
cleaning and/or membrane
change.
"0000" O levels displayed.
2
Shorter than expected sensor
operation in relatively high
dissolved O concentration.
2
Unexpected or inaccurate
dissolved O readings.
2
16 English
Probable cause
Instrument internal
barometric pressure
sensor needs calibration.
Wet membrane
interface.
"H S insensitivity" option
2
enabled.
Wrong reading scale
"XXXX" selected for
display unit.
High O concentrations
2
generate deposits more
quickly.
Air leak on product
sample line.
High residual current.
Possible solution
Calibrate using a certified barometer. Do not
correct for sea level !
Wipe dry with a tissue and re-calibrate.
Disable from the menu on the measuring
instrument.
Change reading scale by selecting "X.XXX, XX.XX
or XXX.X" on the instrument.
Install a less permeable membrane.
Turn off the analyzer when sensor is not in a low
O concentration.
2
Set flow rate to 100 mL/min. Wait until stable, then
slowly double the flow rate.
The stable value of dissolved O
the same as before. A variation related to flow rate
is a clear sign of an air leak in the line.
Place sensor in de-aerated sample and wait for
low reading.
Check concentration against low measurement
limit (refer to Sensor membrane specifications
on page 4).
If concentration is significantly higher than low
limit, try replacing the membrane.
®
mesh
reading must be
2