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Choosing water-quality measurement points in a treatment plant
Place online conductivity, turbidity and pH measurement points where operators can act on the result.
HOSON WATER editorial ·
Assign each reading a decision
List the operating decisions that depend on a measurement, such as product release, diversion, pretreatment adjustment or investigation. Mark the relevant process boundary and whether the measurement represents a single train or a shared header. A sensor on a common outlet may provide overall visibility while leaving operators unable to identify the train associated with a change.
Design the sample path with the instrument
Check pressure, temperature, flow, sample transit time and accessibility. Use manufacturer requirements to decide where a sample conditioning panel, flow restriction, pressure reduction or drain is needed. Confirm that the sampling point represents the process stream and can be checked with a reference sample. Document all shared sample tubing so maintenance staff can trace delays or cross-connections.
Commission the decision as well as the sensor
Verify the tag name, units, scaling, alarm response and signal quality at the operator screen. Compare an instrument reading with the agreed reference method under representative conditions. Show operators how to identify out-of-range measurements and what to do when an instrument is out for calibration.