TERM-MULTI-PASS-TEST
Multi-Pass Test
Filtration Performance
Also: ISO 16889 test · multi-pass filtration test · filter efficiency test
Abbrev: MPT
Canonical Definition
A standardised laboratory test method defined in ISO 16889 for measuring hydraulic filter performance. Test fluid is circulated through the filter element in multiple passes while ISO 12103-1 A2 Fine test dust is injected at a controlled rate upstream. Particle counts are taken upstream and downstream using automatic particle counters per ISO 11171 at defined intervals. The test runs until a terminal pressure differential is reached. Results yield the Beta ratio at each particle size and the dust holding capacity.
Engineering Context
The multi-pass test is the global standard for hydraulic and lubrication filter qualification. Its multi-pass recirculation design allows fine particles to be counted with statistical accuracy across multiple filtration cycles, unlike single-pass tests which cannot control particle concentration precisely at the filter inlet.
Knowledge Center Articles
KC-00 Governance Metadata
| Permanent ID | TERM-MULTI-PASS-TEST |
| Category | Filtration Performance |
| Status | Published |
| Version | 1.0 |
| Last Reviewed | 2026-07-05 |