pHConductivityWaterQualityChecker

pH & Conductivity Water Quality Checker — Control of Pharmaceutical Water Quality

ℹ️  Utility checks critical parameters of Purified Water (PW) and Water for Injection (WFI):
   • Conductivity: ≤1.3 µS/cm (at 25°C, USP <645>)
   • pH: 5.0–7.0 (USP <645> Stage 2 / Ph. Eur.)
   • Temperature compensation of conductivity limits

⚠️  CRITICAL: Exceeding conductivity indicates ionic contamination!
   Incorrect pH may indicate CO2 absorption or ammonia contamination.

Usage:
 pHConductivityWaterQualityChecker.exe                            → demo mode (console output)
 pHConductivityWaterQualityChecker.exe input.csv output.json      → evaluate your data

Input format:
BatchNumber,MeasuredPH,ConductivityUScm,TemperatureC,WaterType

Example:
 WFI-LOOP-2026-001,5.8,0.9,25.0,WFI

— WHY IS THIS NEEDED?
Water is the most widely used substance in pharmaceutical manufacturing.
• USP <645> and Ph. Eur. 2.2.38 regulate methods for conductivity and pH control.
• Conductivity is the primary indicator of water purity (absence of ions).
• pH is controlled to confirm absence of acidic or alkaline contaminants.
• Automation of temperature limit checks eliminates manual table comparison errors.

⚠️  CRITICAL:
• Measurements must be performed online (in-line) or immediately after sampling (at-line) to avoid CO2 absorption from air.
• CO2 absorption lowers pure water pH to ~5.5, which is normal but can be mistaken for contamination.
• Conductivity cell must be calibrated before use.
• For WFI, requirements are stricter than for regular purified water (especially for endotoxins, but here only phys-chem).

Key features:
• Conductivity check with temperature consideration.
• pH range control.
• Support for PW and WFI water types.

Critical parameters:
• Conductivity: <= Limit (Temp Dependent)
• pH: 5.0 - 7.0

💡 Usage tips:
1. Use flow-through cells to minimize air contact.
2. Regularly clean electrodes from biofilms.
3. Check sample temperature as conductivity is highly T-dependent.
4. If conductivity is normal (Stage 1 Pass), pH test may not be required by USP, but is often performed for data completeness.
5. Store conductivity and pH meter calibration data for auditing.

⚠️ Note: Pure water has very low buffer capacity, so its pH is extremely unstable in air. Conductivity is a more reliable and reproducible parameter for purity control.