Understanding ISO 21501-4: Particle Counter Calibration

On Demand Webinar 

ISO 21501-4 has two main goals; to improve instrument-to-instrument data correlation and count accuracy, and to enhance compliance with ISO 14644.

By the end of this webinar, you should have a good understanding of the following concepts and how they affect your cleanroom particle counting efforts:

  • How to be compliant with the most recent calibration requirements
  • Sampling flow rate
  • Counting efficiency
  • Particle counter resolution
  • Pulse height analyser (PHA)
  • False count rate
  • Particle size setting
  • Coincidence loss at maximum particle concentration
  • Maximum particle number concentration


Daniele Pandolfi

Life Science Division, Global Product Line Manager, Aerosol, Particle Measuring Systems

Daniele Pandolfi is the Global Product Line Manager, Aerosol in Particle Measuring Systems’ Life Science Division. He has over eleven years’ experience in particle counter instrumentation and cleanroom contamination control, focusing on strong customer relationships. He has helped many cleanroom users solve their cGMP issues. Mr. Pandolfi has been responsible for the EMEA Service Department, and a member of the Global Life Science organization in 2015.