January 2011 Special ISO Issue

 Journal of the IEST Vol. 54, No. 1 Special ISO Edition - Online January 2011 January 2011
Special ISO Edition
Journal of the IEST

Members Only
Log in for full access
Nonmembers
Complete Tech Talk articles and technical papers’ abstracts (full text by individual sale or subscription)
Subscribe


Peer-reviewed technical paper explains ISO 14644 revisions:
Sampling Plan for Cleanroom Classification with Respect to Airborne Particles

In light of the recent publication of the new Draft International Standards ISO/DIS 14644-1Part 1: Classification of air cleanliness by particle concentration and ISO/DIS 14644-2Part 2: Specifications for monitoring and periodic testing to prove continued compliance with ISO 14644-1 -- and in the interest of educating and enlightening contamination control professionals worldwide -- the following peer-reviewed technical paper is accessible free of charge by clicking here.

Sampling Plan for Cleanroom Classification with Respect to Airborne Particles
Niels Væver Hartvig, Novo Nordisk A/S
Gordon J. Farquharson, Critical Systems Ltd.
Robert Mielke and Mark Varney, Abbott Laboratories
Mike Foster, Consultant

The concentration of airborne particles is a critical parameter for cleanrooms, clean zones, and controlled areas. Particle concentration must be measured at representative locations for classification and monitored routinely or continuously at critical locations during operation. Both ISO 14644-1:1999 and the new Draft International Standard (DIS) edition provide nine classes of cleanliness and specify both the number of sample locations for classification and the acceptance criterion for the data.

In the 1999 version of the Standard, the minimal number of sample locations is not based on statistical principles. The acceptance criterion is based on a statistical test, but only if the number of sample locations is less than 10. Thus, classification is based on statistical methods only for a small number of locations.

The revised ISO/DIS 14644-1 replaces this method with a statistical principle for selection of the sample locations. The acceptance criterion in the revised version eliminates the need for applying a statistical test to the data, and thereby simplifies the classification process.

The purpose of this paper is to present and discuss the new sampling plan for cleanroom classification and compare it with the previous approach in ISO 14644-1:1999. Section 2 of this paper presents and discusses the previous method, section 3 describes the new method in the ISO/DIS 14644-1 revision, and section 4 provides a discussion and conclusion. All of the authors are members of ISO Technical Committee (TC) 209, Working Group 1, the group of experts who developed the new ISO/DIS 14644-1. This paper was written on behalf of the entire Working Group.

View online January 2011 Journal of the IEST, previous issues, and archive
The following links will take you to our online Journal of the IEST website hosted by EBSCO MetaPress or give you subscription information:

Members Only
Log in for full access
Nonmembers
Complete Tech Talk articles and technical papers’ abstracts (full text by individual sale or subscription)
Subscribe