What Is Particle Count Testing?
Particle Count testing involves analyzing the number and size distribution of solid particles suspended in the oil. The results are expressed as a cleanliness code that helps assess oil purity and determine necessary filtration or maintenance actions.
We use advanced laser-based particle counters to quantify contaminants across multiple size ranges, ensuring accurate detection and compliance with global standards.
Test Standard
- NAS 1638: Cleanliness standard originally developed for aerospace hydraulic fluids; adapted for industrial applications
- ISO 4406: International cleanliness code using a 3-number format (e.g., 18/16/13) for particles ≥ 4μm, 6μm, and 14μm
Key Gases Measured
Insulating Liquids – Measurement of Relative Permittivity, Dissipation Factor (Tan δ) and DC Resistivity.
| ISO 4406 Code | Particle Count/mL (≥4μm / ≥6μm / ≥14μm) |
Cleanliness Level |
|---|---|---|
| 14/12/10 | Very low | Very Clean (new oil / post-filtration) |
| 17/15/12 | Low to moderate | Normal (in-service transformer) |
| 20/18/15 | High | Contaminated – filtration advised |
| 22/20/18+ | Very high | Critical contamination – immediate action |
Why Particle Count Testing Matters
- Detects harmful solid contaminants before they cause failure
- Ensures safe dielectric performance and oil circulation
- Supports predictive maintenance and filtration strategies
- Required for quality control of new or reclaimed oil
- Helps assess oil cleanliness during commissioning or repairs
Our Testing Process
- Vacuum-sealed sample collection with barcode tracking
- ISO 4406 & NAS 1638 particle analysis using laser particle counters
- 3-channel size classification: ≥4μm, ≥6μm, ≥14μm (ISO); and NAS range
- Visual inspection (optional) for fiber, metal, and sludge presence
- ERP-integrated reporting and cleanliness trend tracking
Report Includes
- ISO 4406 and/or NAS 1638 cleanliness code
- Particle size distribution table and chart
- Status classification (Clean / Alert / Critical)
- Recommendations for filtration, oil change, or root cause analysis
- Comparative trend analysis (if historical data is available)
Why Choose Tru-FIL?
- ISO 4406 & NAS 1638-compliant testing
- NABL-accredited lab with certified particle analysis equipment
- AI-powered ERP reporting for instant insights and history
- Nationwide vacuum-based sample pickup
- 24/7 laboratory operations and fast turnaround time