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4.2 Calibration Notes
1. A Span calibration should be performed at least weekly. In applications where
the sensor can become dirty or coated, such as sewage effluent, mining slurries
etc, a Span calibration may have to be done daily.
2. The Zero calibration is quite stable long term. Monthly Zero calibration is
recommended, mainly as a routine check.
3. Both a Zero and a Span calibration need to be performed when the membrane is
replaced.