BS 8465:2010 Hydraulic fluid power. Monitoring the level of particulate contamination. Comparison membrane technique
In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure within an enclosed circuit. The liquid is both a lubricant and power-transmitting medium. The presence of solid particulate contamination in the liquid interferes with its ability to lubricate and causes wear to the components. The extent of contamination in the liquid has a direct bearing on the performance and reliability of the system and has to be controlled to a level appropriate for the system concerned. The level of particulate contamination is usually determined by extracting a liquid sample from the hydraulic system and analyzing it for the number of particles at various sizes, often in a laboratory.
BS 8465:2010 is a British Standard which specifies methods to assess the level of particulate contamination in hydraulic liquids using an optical microscope. It includes assessment by two manual methods using either transmitted- or incident-lighting systems. It also includes procedures for evaluating and controlling the accuracy of the technique that ensure reproducible results.
Contents of BS 8465:
Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Equipment
6 Chemicals
7 Preparation of reference membrane filters
8 Procedures
9 Test report
Annexes
Annex A (informative) Typical worksheet
Annex B (informative) Potential problems associated with preparing membrane filters
Bibliography
List of figures
Figure 1 – Typical comparison microscope
Figure A.1 – Typical worksheet