Particle Counting — ISO 11500 / ISO 4406 / ISO 4407

What Is Particle Count?

Particle counting is the counting of solid particles in the fluid according to their size ranges. In the automatic method (ISO 11500) the blocking of laser light by particles is measured; In the microscopic method (ISO 4407), the particles collected on the membrane are counted. The result is converted into a three-number cleaning code according to ISO 4406.

Purpose of Particle Count

The aim is to compare the cleanliness level of the fluid with the target class and prevent failures caused by contamination. The majority of malfunctions in hydraulic and lubrication systems are caused by particle contamination.

Which Products Is Particle Count Applied To?

Hidrolik sistemler
Lubrication and circulation systems
Turbine oil systems
Fuel systems and tanks
New oil delivery samples

In Which Sectors Is Particle Count Used?

Oil & GasPetrokimyaEnergyIndustrial EquipmentMachineryAerospace

Standards Related to Particle Count

TS ISO 11500 (automatic particle counting — light blocking)
TS ISO 4406 (coding of cleanliness level)
TS ISO 4407 (microscopic counting)
TS ISO 11171 (calibration of particle counters)
TS ISO 12103-1 (test powders)

Particle Count Conditions

Specimen container: Cleaning class certified, particle-free bottle is mandatory
sample point: From the pressure line, when the system is running and from the turbulent zone
gas bubbles: Bubbles are counted as particles; sample must be degassed
Calibration: The counter must be calibrated according to ISO 11171

Equipment for Particle Count

Automatic particle counter
Vacuum degassing device
Membrane filtration and microscope
Sample bottles with cleanliness class certification
Ultrasonic bath

Sample Requirements for Particle Count

Certified clean bottles should be used; ordinary bottle invalidates the result
The sample should be taken from the same point and with the same method while the system is running.
The line must be sufficiently flushed before sampling.
Hedef ISO 4406 kodu bildirilmeli

Duration of Particle Count

Measurement is fast; The results are obtained in a short time, including sample preparation and degassing.

Particle Count Procedure

1The sample is taken into a certified clean bottle.
2The sample is homogenized in an ultrasonic bath.
3Gas bubbles are removed.
4It is passed through an automatic counter.
5Particle numbers are obtained according to size ranges.
6ISO 4406 cleanliness code is calculated.

Particle Count Acceptance Criteria

The acceptance criterion is the ISO 4406 cleanliness code required by the manufacturer of the most sensitive component in the system. For new oil deliveries, the target code in the supply specification is applied.

Evaluation of Results

Sampling determines the reliability of the result: it measures sampling error, not an uncertified bottle, pick-up from a stagnant zone, or inadequate dispensing system. Additionally, water and air bubbles can be counted as particles; so degassing and water content need to be known.

Particle Count Report

System description and sampling point
Sample bottle cleaning certificate information
Particle numbers according to size ranges
ISO 4406 temizlik kodu
Comparison with target code
Water content information, if available

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

Fuel and LPG market technical regulations (EPDK)
EU 2009/30/EC (fuel quality directive)
Communiqués on the placing of lubricating oils on the market

Petroleum, Fuel and Oil Analysis — What Does This Testing Field Cover?

The section below describes the field that the Particle Count test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

Petroleum, fuel and oil analysis determines whether a fluid meets its specification and how it behaves in use. Standards in this field consist largely of ASTM and EN publications, with a separate method defined for each parameter.

What distinguishes this family is that product specifications are written as PARAMETER LISTS. Specifications such as EN 590 (diesel), EN 228 (petrol), EN 14214 (biodiesel) and ISO 8217 (marine fuels) state for each parameter both the limit and the method by which that limit is to be measured. If the method changes the result may change too; the specification therefore binds the method as well, and the use of an "equivalent method" is possible only where the specification allows it.

On the fuel side, parameters describe three different properties of the product. Physical properties (density, viscosity, distillation curve, pour point, cloud point) determine pumpability and cold weather behaviour. Combustion properties (cetane number, octane number, calorific value) indicate performance in the engine. Contaminant and stability parameters (sulphur, water, sediment, oxidation stability, copper strip corrosion) affect both emissions and storage life.

Oil analysis is carried out for two different purposes and the two must not be confused. Analysis of NEW oil verifies the conformity of the product to its specification: viscosity index, additive content, flash point. Analysis of USED oil, by contrast, is done to read the condition of the machine — elemental analysis shows wear metals (iron, copper, chromium, aluminium), water and fuel contamination point to leaks, and oxidation and acid number determine the remaining life of the oil.

Used oil analysis is therefore a PREDICTIVE MAINTENANCE tool. The trend of samples taken at regular intervals is followed; it is the trend rather than a single result that is meaningful. Iron levels climbing over the course of months allow intervention before a failure occurs.

Marine fuels are the most active sub-body of the field. The global tightening of sulphur limits has brought new blended fuels onto the market; for these fuels stability, compatibility (whether two fuels form deposits when mixed) and catalytic fines content have become critical parameters.

Sampling is part of the result in this family too. A sample taken from the bottom of a tank shows different water and sediment content from one taken from the upper level; in commercial deliveries the sampling point and method are set by contract.

Method groups in this field

Physical properties
Density (oscillating U-tube and hydrometer), kinematic viscosity, distillation, pour and cloud point, flash point.
Combustion properties
Cetane number and cetane index, research and motor octane number, calorific value.
Sulphur and elements
Sulphur by UV fluorescence and XRF; elemental analysis and additive content by ICP.
Stability and corrosion
Oxidation stability, copper strip corrosion, water and sediment, filter blocking tendency.
Composition analysis
Boiling range distribution by gas chromatography, hydrocarbon types (FIA), benzene and aromatics content, fatty acid methyl ester content.
Used oil
Wear metals, contamination (water, fuel, soot), oxidation, acid and base number, change in viscosity.

Commonly confused in this field

The specification binds the method as well; a result measured by a different method may not be accepted for specification conformity.
A single result on used oil is not meaningful; the decision is made on the trend.
The sampling point determines the result; the tank bottom and the upper level show different water and sediment.
The cetane index is a calculated value and is not the same thing as a measured cetane number.
Fuels blended with biodiesel behave differently in terms of storage life and microbial growth; classical diesel parameters are not sufficient.
Mixing marine fuels from different sources can cause deposits; compatibility is assessed separately.

Which decisions these results support

Conformity of a fuel lot to specification and commercial delivery
Predictive maintenance decisions based on used oil analysis
Determining parameters for customs and tax classification
Quality verification after storage, blending and transport
Compliance with sulphur limits under emissions legislation

Related Tests

Frequently Asked Questions About Particle Count

Is the new oil we bought clean?

Most of the time no. New oil becomes contaminated during production and transportation and is delivered below the target cleanliness class of many systems. Therefore, it is common practice to filter new oil into the system.

Census results are very variable, why?

The most common causes are sample bottle cleaning, flow regime at the sample point, and gas bubbles. Standardizing the sampling procedure significantly reduces variability.