BS EN 60970:2007

INTRODUCTION
1 Scope
2 Normative references
3 General caution, health, safety and environmental
   protection
4 Significance
5 Comparison and limitation of the methods
6 Types and identification of particles
7 Sampling
   7.1 General remarks
   7.2 Sampling vessels
   7.3 Cleaning of sampling bottles
   7.4 General directions for sampling
   7.5 Sampling procedure
   7.6 Labelling of samples
        7.6.1 Samples from tanks
        7.6.2 Samples from electrical equipment
8 Preparation of the samples for analysis
9 Method A - Automatic particle size analyzer
   9.1 Summary of method
   9.2 Apparatus and auxiliary materials
   9.3 Calibration procedures
   9.4 Preparation of the apparatus for counting
   9.5 Preparation of sample before counting
   9.6 Preparation of sample for counting
   9.7 Counting procedures
   9.8 Report
   9.9 Precision
   9.10 Repeatability
   9.11 Reproducibility
10 Method B - Optical microscopy
   10.1 Principle
   10.2 Procedure by transmitted light
   10.3 Procedure by incident light
Annex A (informative) Use of syringes as sampling vessels
Annex B (informative) Calibration of the automatic particle
                      counters
Annex ZA (normative) Normative references to international
                      publications with their corresponding
                      European publications
Bibliography

Defines the sampling procedures and methods for the determination of particle concentration and size distribution.

This standard describes the sampling procedures and methods for the determination of particle concentration and size distribution.

Three methods are specified. One uses an automatic particle size analyser, working on the light interruption principle. The other two use an optical microscope, in either the transmitted light or incident light mode, to count particles collected on the surface of a membrane filter. The optical microscope methods are described in ISO 4407.

All three methods are applicable to both used and unused insulating liquids.

Annex A contains an alternative sampling procedure using a syringe and Annex B reports a reference for the calibration of automatic particle counters.

NOTE 1 The methods are not intended to measure particulate matter in liquids containing sludge. While analysing solid content on oils containing sludge refers to method for sediment and sludge determination in IEC 60422, Annex C.

NOTE 2 The methods specified are only applicable to measurements related to a limited range of size and number.