GB/T 20082-2006Hydraulic fluid power -- Fluid contamination -- Determination of particulate contamination by the counting method using an optical microscope (English PDF)

Foreword

This Standard is identical to the international standard ISO 4407:2002

"Hydraulic fluid power - Fluid contamination - Determination of particulate

contamination by the counting method using an optical microscope" (English

edition).

For ease of use, this Standard makes the following modifications to ISO

4407:2002:

- ADD a view to Figure 1 and re-arrange the key;

- CHANGE Figure 3 to Table 2 and the "Note" of Figure 3 to the table note of

Table 2;

- For reference standards, replace international standards with

corresponding national standards.

This Standard was proposed by China Machinery Industry Federation.

This Standard shall be under the jurisdiction of National Technical Committee 3

on Hydraulic Pneumatics of Standardization Administration of China (SAC/TC

3).

Drafting organization of this Standard: China Aviation Industry Granularity

Measurement and Test Station.

Main drafters of this Standard: Lu Hong, Zhang Sufang, Guo Guixia, Wang Yan.

This Standard is first issued.

Hydraulic fluid power - Fluid contamination -

Determination of particulate contamination by the

counting method using an optical microscope

WARNING: The use of this Standard may involve hazardous materials,

operations and equipment. This Standard does not purport to address all

the safety problems associated with its use. It is the responsibility of the

user of this Standard to establish appropriate safety and health practices

and determine the applicability of regulative limitations prior to use.

1 Scope

This Standard specifies methods for determining the level of particulate

contamination in liquids used in hydraulic systems by counting the number of

particles deposited on the surface of a membrane filter using an optical

microscope. It includes particle counting by two manual methods and image

analysis, using either transmitted or incident lighting systems.

Particle sizes >= 2 µm can be sized and counted by this method, but the

resolution and accuracy of the results will depend upon the optical system used

and the capabilities of the operator.

All hydraulic fluids with a wide range of contamination levels can be analysed

according to this Standard. However, the counting uncertainty at the larger

particle sizes increases if the volume filtered is reduced to allow smaller sized

particles to be counted, where a fine precipitate or a high particle concentration

is present.

2 Normative references

The following documents contain provisions which, through reference in this

Standard, constitute provisions of this Standard. For the dated references, their

subsequent amendments (excluding corrections) or revisions do not apply to

this Standard. However, the parties who enter into agreement based on this

Standard are encouraged to investigate whether the latest editions of these

documents are applicable. For undated reference documents, the latest

editions apply to this Standard.

GB/T 12804 Laboratory glassware - Graduated measuring cylinders (GB/T

12804-1991, eqv ISO 4788:1980)

9 Membrane filter preparation