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The Greystone CR3A cleanroom monitors are used for the accurate and reliable monitoring of confined spaces. Most cleanrooms are used for manufacturing products such as electronics, pharmaceutical products, and medical equipment. In this article, we’ll take a closer look at cleanrooms and the way that Greystone products can ensure accurate and reliable monitoring of these rooms. 

We have all seen them in movies where they have rooms with airlocks and people wearing hazmat suites working in them. But, for our purposes, a cleanroom is:

a controlled environment where pollutants like dust, airborne microbes, and aerosol particles are filtered out to provide the cleanest area possible. 

Greystone Cleanroom monitors

Particle levels are usually evaluated using a particle counter and microorganisms detected and counted through environmental monitoring methods.

Air temperature and humidity levels inside a cleanroom are tightly controlled because they affect the efficiency and means of air filtration. Pressure is also monitored to ensure either positive or negative air pressure as required.


  • Integrated sensors for temperature, humidity and pressure within the space it’s mounted in
  • Output signal of either Analog, BACnet ® or Modbus
  • Adjustable alarm relays for each parameter, audible/visual alarms, and large LED displays
  • Housed in a flush fitting stainless steel front plate 


  • The CR3A should be mounted inside an opening in the wall, 210 mm wide x 167 mm high
  • Ensure the unit can be secured to a wall stud or equivalent on at least two sides

Check out the Greystone Energy Solutions CR3A Cleanroom monitor 

Cleanroom design

Depending on the purpose of the cleanroom, it is either kept at a positive or negative pressure. Positive pressure is maintained so that if any leaks occur, air leaks out of the chamber instead of unfiltered air coming in. 

This is important in semiconductor manufacturing, where even minute amounts of particulates leaking in could contaminate the entire process, while anything leaking out is not harmful to the occupants of the surrounding area. 

Negative pressure cleanrooms are used in the case of the handling of toxins or viruses in bio-laboratories where in the event of a leak, the negative pressure allows outside air in, thereby preventing dangerous organisms and material escaping. 

Both are maintained at exceptionally low particulate levels, meaning that reliable sensors are a must.

Cleanroom standards

There are a range of ISO standards for clean rooms ranging from the ISO 1 specification up to ISO 8: 

“The ISO 8 is the least clean cleanroom classification. For this standard, a cleanroom must have less than 35,200,000 particles >0.5 micron per cubic meter and 20 HEPA (High Efficiency Particulate Air) filtered air changes per hour. As a comparison, a typical office space would be 5-10 times more polluted than this.

At the other end of the spectrum is the ISO 1 specification. This specification requires less than 2 particles greater than 0.3 microns and no particles greater than 1.0 microns per cubic meter. An ISO 1 cleanroom will typically have between five hundred and seven hundred and fifty air changes per hour and use ULPA (Ultra-low Penetration Air filter) filtration.”

A cleanroom is as much a process and a meticulous culture to maintain, as it is a space! With the Greystone CR3A Cleanroom Monitors, not only can you be sure of reliable monitoring, but versatile BACnet ® or Modbus communication as well.

Contact our team to find out more about ordering and pricing today!