RO Performance & Troubleshooting Analyzer
Enter the current, measured run and the baseline (commissioning) reference. The analyzer normalizes the current permeate flow to 25 °C and to the baseline net driving pressure the way the ASTM D4516-style procedure does, so a production decline shows up even when feed pressure was raised to hold output.
Baseline — commissioning reference
Current — measured today
Assumptions behind this analysis
Method and references
Current permeate flow is normalized as Qn = Qm × (TCF_ref / TCF_use)
× (NDP_ref / NDP_use), where NDP is the net driving pressure
Pfeed,avg − Ppermeate − (πfeed
− πpermeate), with the feed-side average pressure taken as
feed pressure minus ΔP/2. Osmotic pressure uses the simplified van ’t Hoff model of the
RO osmotic-pressure engine (van ’t Hoff factor 2.0, NaCl 58.44 g/mol).
Temperature correction uses the ≈3 %/°C approximation. It is a documented shortcut: use the membrane maker’s own temperature-correction factor when available. The pressure-drop check flags an excursion beyond ±10 % of baseline as an indicative signal; that value is an internal working rule, not a maker limit.
- ASTM D4516-19, Standard Practice for Standardizing Reverse Osmosis Performance Data — normalization approach.
- Engine:
performance.ts(this analyzer), RO osmotic-pressure engine (calculateRoOsmoticPressure). - Diagnostics are directional and end with ‘verify’: this analyzer never assigns a foulant type or a cause.
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