1. Nephelometer Introduction & Operation

2. What is a Nephelometer? The Nephelometer is an analytical instrument used to measure the light-scattering coefficient of atmospheric and indoor aerosols. It measures the particulates in the air. The main uses of Nephelometers relate to air quality measurement for pollution monitoring, climate monitoring and visibility. A nephelometer has different levels of sensitivity depending on the design.

3. Why the Strange Name? The term nephelometer is derived from the Greek word nephos, meaning cloud. The first nephelometers were developed about 100 years ago to measure the turbidity level (cloudiness) of water samples. The first application for dust in air came along about 50 years ago. The first dust nephelometer used a Jeep headlight as a light source. Today, we use a small laser.

4. 3 Types of Dust Heavy Dust - The layer of dust on furniture and floors. Settling Dust - Particulate’s in the air floating around before it turns into heavy dust. Suspended Atmospheric Dust - Minute particles slowly settling or suspended by slight currents and existing in varying amounts in all air.

5. Airborne Particulate Airborne particles are commonly either biological contaminants, particulate contaminants, gaseous contaminants or dust.

6. The Human Airway System Met One Instruments Proprietary Alveolar Region Alveolar Region Trachea-Bronchial Region Head Airways Region Head Airways Region

7. Design Intention Our Nephelometers Are Designed such that Their Response Has Strong Overlap with Human Alveolar and Trachea-Bronchial Deposition Alveolar Trachea-Bronchial GizNeph Engine Met One Instruments Proprietary

8. Theory of Operation

9. Why Sheath Air is Important Prevents Engine Contamination. Improves Response Time. Fig. 1 Fig. 2 W/OUT SHEATH AIR W/ SHEATH AIR

10. Handheld Nephelometer Protective Inlet Flow Adjust Charging Jack Iso-kinetic Inlet Select/Mode ON/OFF / Sample Zero Cap

11. Operation Be sure the inlet is open Depress the Start/Stop Key for a few seconds to power up the unit. The display will show the units (µg/M3), the sample mode (Manual) and the selected K Factor (Arizona Road Dust) Use the select key to change settings. Use the Start/Stop key to start a sample.

12. K Factors The K factor corrects the reading to a certain type of dust The unit comes with 3 K-factors already in the library. These are Arizona Road Dust (ARD), Limestone and Coal Fly Ash. Other K factors may be determined through side-by- side sampling with a gravimetric sampler.

13. Sampling Mode There are three sampling modes The Manual Mode takes a one minute sample and shuts off automatically The STEL Mode takes a 15 minute sample and shuts off automatically The Continuous Mode runs until you shut it off

14. Datalog & PC Interface The data from the Nephelometer may be downloaded to a PC The software is included with each unit sold It allows storage of data, the addition of new K factors to the library, and the setting of the functions like the clock You can also export data as a.csv file, which can be converted to Excel.

15. USB Port Filter Port Filter Replacement The Dust Monitor has a 0.2 micron filter to produce the clean air for the sheath system. This filter will normally need to be changed on an annual basis but may require a more frequent change if used in extremely dirty environments.

16. Reliability COMPONENTNORMAL USAGECONTINUOUS USAGE ELECTRONICS>10 YEARS>5 YEARS FIRMWARE / SOFTWAREFIELD UPGRADABLE BATTERY>3 YEARS>1 YEAR PUMP>3 YEARS>1 YEAR CONTAMINATIONVARIABLE AMBIENT LIGHTVARIABLE ZERO STABILITYVARIABLE LASER DIODE>10 YEARS>5 YEARS

17. Benefits Portable light weight unit Easy Operation Instant Readings Highly Sensitive Competitively Priced Monitoring Software Included Low Cost of Ownership Long Life Pump Automatic Power Save Selectable Sample Modes Sheath Air w/ user replaceable filter

18. Common Applications Indoor Air Quality Investigation Industrial Hygiene Quality Control Occupational Health Control Walk Through Surveys Particulate Matter Study Workplace & Plant Monitoring Evaluating Dust Generation / Suppression Emissions Monitoring HazMat Investigations Emergency Response Site Boundary Monitoring & Environmental Measurement Industrial Process Monitoring Testing Air Filtration Efficiency Aerosol Research Studies Personal Exposure Monitoring Remediation Personal Surveillance Outdoor Environmental Monitoring Baseline Trending & Screening

19. Thank You