How do Level 100, Level 1,000, and Level 10,000 correspond to ISO levels?

The expressions '100-level, 1,000-level, and 10,000-level' can still be seen in many old factory drawings and technical documents. When doing renovation or new construction projects, it is often necessary to convert them to ISO levels to facilitate docking with current standards.

But when it comes to conversion, you can't just look up a table and be done.

Under the traditional caliber based on particle concentration comparison of no less than 0.5 μm, level 100 roughly corresponds to ISO 5, level 1000 corresponds to ISO 6, level 10,000 corresponds to ISO 7, and level 100,000 corresponds to ISO 8. This comparison relationship itself is clear and is also a commonly used reference in the industry.

The problem is that the traditional title and ISO's expression caliber are not exactly the same. Drawing equal signs directly can easily leave hidden dangers in the contract, acceptance and equipment selection links.

The traditional appellation and the ISO expression caliber are different

The old names of Class 100 and Class 1000 are usually defined by the number of particles per cubic foot of air, and most only refer to a particle size of no less than 0.5 μm.

The ISO 14644 series uses unit volume concentration, and particle size conditions can be selected. The same grade has different limits at different particle sizes, and standards have applicable ranges for combinations of grades and particle sizes.

Putting the two systems together, there are at least three things that need to be checked: volume unit 、statistical particle size 、operating status . If the units are not unified, the numbers cannot be directly transferred; if the particle size is not clear, there is no basis for the limit value; if the status is different, the results cannot be compared with each other.

Therefore, the comparison table can be used to understand the old title, but it cannot be used as the final expression of the technical document.

Contracts and technical documents must use the full ISO grade

If the project requirement is '10,000-level', it is recommended to supplement the technical document with a complete ISO level expression.

The complete description includes at least: ISO grade 、measurement particle size 、area boundary 、operating status . For example, write 'ISO 7, not less than 0.5μm, dynamic, designated assembly area', so that there is a clear basis for acceptance.

If you only write 'Class 10,000' or 'ISO 7', the acceptance personnel will not know which particle size to measure, under what conditions, and which area to measure. If the two parties have inconsistent understandings, it will be easy to argue over the acceptance.

For old drawings, don't just change 'Level 100' to 'ISO 5' and end it. The definition of the original document should be traced back to confirm the particle size, unit and status requirements at that time, and then combined with the actual needs of the current process to determine whether adjustments are needed.

After level conversion, the equipment configuration needs to be rechecked.

After the old name is converted to the ISO level, the equipment configuration cannot directly use the original solution.

The reason is that the original 100-level and 1000-level equipment may have been designed according to old standards and old working conditions. Now that the process equipment has changed, the number of personnel has increased, and the exhaust conditions have changed, the air supply volume, filtration efficiency, and air flow organization requirements corresponding to the same ISO level may also be different.

Filtration efficiency, air volume and static pressure, supply air coverage, and return air path should be checked together. If the filter efficiency reaches the standard, it does not mean that the system air supply volume matches; if the air supply volume matches, it does not mean that the air flow organization can cover the protection area.

Aili Industrial has manufacturing capabilities in motors, fans, control systems, sheet metal, air filters and complete machine assembly. When doing cleanliness level conversion or old factory renovation projects, filters, fans, structures and control conditions can be checked in the same project to make the equipment configuration consistent with the new ISO goals. Related products can be viewed FFU clean air supply products and HEPA and ULPA filters , please refer to the local purification on the equipment side. EFU equipment side fan filter unit。

Project judgment example

The drawings of an old factory building are marked 'Class 10,000', and the FFU was directly configured according to ISO 7 during the renovation. After running, it was found that the particle concentration was high in some areas.

The investigation found that the original drawings were marked according to static conditions, but the modified process required dynamic compliance. Static and dynamic particle loads are different, and the original equipment configuration does not cover dynamic conditions. When adjusting the plan, dynamic test requirements were added, and the air supply volume and filtration configuration were rechecked based on actual dust production conditions.

In another project, after 'Class 100' was directly changed to 'ISO 5', the particle size and status were not indicated, and the two parties had inconsistent understanding of the test conditions during acceptance. Later, a complete statement was added to the technical agreement, and the problem was solved.

These two cases illustrate that traditional names can be compared, but formal requirements must be expressed in complete ISO grades and checked against actual working conditions.

Key points for selection and acceptance inspection