1. Particle Physics and Particle Counting for IH&S and IAQ
Thomas J. Grillo, Jr.
Particles Plus, Inc.

2. Overview Particle Behavior Particle counters & what are we detecting
Types of Particle Counters
Typical Features and Operation
Q & A

3. Particles and their behavior
Particles come in all different types, shapes and sizes.
A human hair is µm in size
The human eye can see 40 micron size particles
Particle size effects their behavior
Gravity vs. Brownian Motion Effect
Settling rate influenced by size, shape, and density.
Particles relative to Indoor Air Quality & IH&S
Particles can deposit in human lungs
Particles affect human health
size and shape affect IAQ performance

4. Particles and their behavior
Brownian Motion
Smaller particles and atoms influence larger particles’ direction and speed of motion in a liquid or gas
Gravity
Particles > 5.0 µm – falling debris
Partilcles < 5.0 µm – tendency to remain airborne - suspension
Aerodynamic shape and density play a role
Environmental influences
Airflow/Ventilation/Occupancy

5. Air Quality Monitoring

6. What is a Particle Counter – How it works
A particle counter is an instrument or sensor that detects and counts physical particles. The nature of particle counting is based upon either light scattering, light obscuration, or direct imaging. A high intensity light source (typically a laser) is used to illuminate particles as they pass through the detection chamber. As a particle passes through the light source and if light scattering is used, then the redirected light is detected by a photo detector. (Wikipedia)

7. Why use a particle counter?
Detect
Monitor
Analyze
Remediate and Prevent

8. Why use a particle counter?
To provide a quantitative analysis of airborne particulate for
quality control
regulatory requirements for public health and safety
limiting liability
Monitoring for employee (or occupant) health and safety
Air Quality Analysis for resolving & remediating

9. Types - Air Quality Monitors
Used to monitor in fixed location for long term analysis
Includes Particulate, Temp, RH, CO2 & TVOC

10. Types - Handheld Particle Counters
Mobility – Ideal for site investigation
Establish a baseline for airborne particulate levels. Post remediation checks before clearance testing.

11. Types - Remote Particle Counters
Wall mount versions for fixed construction barrier applications
Long term onsite analysis for PM or direct counts

12. Types – Dust Monitors
Most prevalent in IH&S applications for mass concentration measurments
Limited by mechanical impactors or cyclones

13. Types – Gravimetric Sampling
Fixed flow pumps with impactors or cyclones utilizing pre-weighed filter media that can collect a sample over time and the weight can be rechecked by a lab for a value in mass concentration (µg/m³)
Can also be evaluated by Microscopy for quantitative and qualitative analysis.

14. Types – other technologies – R&D
Differential Mobility Analyzers
CPC - Condensate Particle Counter
Piezo Balance – Wetted particles
CPC – Quantitative only
Beta Ray Attenuation – continuous outdoor monitoring

15. Air Quality Monitoring
Using a Particle Counter
Air Quality Monitoring

16. User Interface – Main Screen
The instrument calculates
Count/M³ based on the
Flow rate of the instrument and the duration of the sample
0.3 = 583,392
0.5 = 50,976
1.0 = 25,134
2.5 = ,726
5.0 = ,770
10.0 =
Displaying Raw Counts in both
cumulative and differential counts

17. Understanding ISO 14644-1 Particle Counts

18. User Interface – Main Screen

19. User Interface – Air Quality Monitoring

20. User Interface – Geiger, Beep or Real-time Meter Modes
Provides a auditory (or visual and auditory) means of displaying current particle count activity that can be used to help locate particulate sources (shown with range slider to adjust sensitivity)

21. Sampling and Logging Log individual data records Locations and recipes
Newer features like annotations and on screen statistics

22. Processing Power More advanced with multiple microprocessors onboard
Allows for simultaneous processing of particle counts, accessing settings, viewing saved records, downloading data, and supporting many communications sessions.
Concurrent Communications interfaces include:
Multiple Modbus sessions (wired and WiFi)
Multiple web-server sessions (wired and WiFi)
USB data-download and configuration
USB printer or thumb-drive

23. Intelligent Peripherals
Swappable peripherals allow more flexibility for each instrument – other environmental or air flow related.
Allows instrumentation to be configured for the task-at-hand (IAQ, H&S, QC, Certification & Validation)
Allows instruments to expand over time to add new features – handheld probes, etc.

24. Instrument Management Software
Real-time graph allows for instrument operation and control
Saves data for historical review, reporting and analysis

25. Instrument Management Software
Self-calibration of TVOC, CO2, Temperature and Humidity sensors
Allows for remote service and upgrades

26. Q&A
Thank You!