Hach ORBISPHERE 51 Series User Manual page 108

8. Tighten the protection cap finger tight. Then, complete the process using the tool provided
in the maintenance kit. Insert into each of the four holes in turn, and tighten as far as
possible. Tighten each hole only once.
Note: The grille inside the protection cap should be free to move during tightening. Therefore, and to avoid
damage to the membrane, do not touch the grille during the tightening process.
9. Always store the sensor in a dry environment, with the storage cap installed.
Note: A sensor that has been taken apart, or serviced must always be calibrated. Allow the sensor to settle
for 30 minutes to allow measurements to stabilize and the membrane(s) to relax, before performing the
sensor calibration.
Calibrate the sensor to check that the membrane has been installed correctly and not been
damaged. If an error message (illustrated right) appears on your instrument, then the membrane
has been damaged or incorrectly installed.
Maintenance and Troubleshooting
Figure 49 Installing the membrane
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