Declining normalized RO permeate flow and flux
Use this when declining normalized ro permeate flow and flux is observed but the cause remains unclear. The diagnostic checks measurement and sampling, operating changes, issue location, and key evidence before suggesting likely causes and the next useful check.
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You do not need every data point before you begin
The system asks one discriminating question at a time and updates the candidate causes on the right. Answer from current facts; choose unknown or defer a question when the evidence is not available.
- 1
Confirm the issue
Check whether the symptom is reproducible and whether the measurement or observation is reliable.
- 2
Narrow the causes
Continue through operating changes, issue location, and available inspection results.
- 3
Read the live result
Candidate causes, support, counter-evidence, conflicts, and next actions update as you answer.
This tool analyzes information you already have. It does not insert a safety screen or use safety status to stop the diagnosis. If an alarm, leak, or injury is happening now, follow the site emergency procedure directly.
Automatic troubleshooting · Selections are not uploaded
Only one question is shown at a time. Answer from current facts or defer an unknown item. Possible causes and next checks update on the right as you answer.
- 1Data validity
- 2Operating changes
- 3Issue location
- 4Further confirmation
Question progress
0/17
- Answered
- 0
- To confirm
- 17
- Clues found
- 0
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Next question
Phase 1 · Data validity
Is the flow decline confirmed by an independent method or simultaneous mass balance?
The system asks the question most useful for separating possible causes. Unknown or deferred items are not treated as the opposite conclusion.
I have more test or inspection resultsOptionalAdd laboratory analysis, normalized calculations, or checks completed by trained personnel when available. These fields are optional.
View rule sources (10)Standards, regulations, OEM material, and peer-reviewed literature used to audit the diagnostic logic. You do not need to read them before starting.
Each rule cites material directly relevant to its judgment. Current OEM and site procedures remain controlling.
- A-standard · ASTM International · 2019ASTM D4516-19a — Standard Practice for Standardizing Reverse Osmosis Performance Data
- A-standard · ASTM International · 2023ASTM D4194-23 — Standard Test Methods for Operating Characteristics of Reverse Osmosis and Nanofiltration Devices
- A-standard · ASTM International · 2023ASTM D4472-23 — Standard Guide for Recordkeeping for Reverse Osmosis and Nanofiltration Systems
- A-standard · ASTM International · 2023ASTM D4189-23 — Standard Test Method for Silt Density Index (SDI) of Water
- A-standard · ASTM International · 2024ASTM D8002-24 — Standard Test Method for Modified Fouling Index (MFI-0.45) of Water
- A-oem-current · DuPont Water Solutions · 2026FilmTec Reverse Osmosis/Nanofiltration Membranes Technical Manual, Rev. 19
- B-independent-oem-current · Hydranautics / Nitto · 2026TSB107.29 — Foulants and Cleaning Procedures for Composite Polyamide RO/NF Membrane Elements
- B-independent-oem · LG Water Solutions · 2025Technical Service Bulletin 111 — Data Logging and Performance Normalization
- B-independent-oem · LG Water Solutions · 2025LG Water Solutions Technical Service Bulletins 101–116, Version 2.4.1
- C-peer-reviewed-review · Science of the Total Environment · 2017A review of reverse osmosis membrane fouling and control strategies