Particulate Sampling (Aerosols/Dust Vapors). TSI Quest Quest Environmental Monitor EVM Series, EVM-7

2 Introduction

Particulate Sampling (Aerosols/Dust Vapors)

Particulate Sampling (Aerosols/Dust Vapors)

The EVM is a portable-area monitoring instrument with a laser-photometer that measures and stores concentration levels of airborne-dust over time. It is designed to measure and help you identify the air pollutants, existing as matter (gases and aerosols) in the environment. The methodology used entails a handful of components including: an air inlet, the impactor (which is the particle size selector), the collection of particulates, gravimetric sampling, and the pump which are addressed in the upcoming sections.

Particulate Path

(1) TURRET

Air travels though the impactor and the larger, heavier particulates will stick to the greased plates within the impactor.

(2) OPTICAL ENGINE

While the pump maintains the flow rate, the smaller lighter particulates will pass through the optical engine.

(3) GRAVIMETRIC CASSETTE

The particulates will collect/trap in the gravimetric filter/cassettes.

❶

(4) PUMP

The remaining clean/filtered air passes through the pump.

(5) FLOW SENSOR

The clean/filtered air passes through flow sensor (flow-control orifice hole).

(6) OUTLET

Lastly, it passes through to the Outlet on the back of the instrument.

❻

❷

❺

❸

❹

Figure 1-1: Particulate path diagram

EVM Series User Manual

3 Introduction

Particulate Sampling (Aerosols/Dust Vapors)

Particulate Sizes

Aerosols and gases are experienced in industrial processes, workplaces, and in everyday life. Keeping in mind that inhalable dust is 100 microns and smaller, this dust is usually filtered through the hairs and membranes in your sinuses. 10 microns and smaller is considered “thoracic”, 4-10 microns is “inhalable” reaching into your windpipe and other regions, and 4 microns and smaller is “respirable”. These particulate sizes will represent what you will be measuring.

The figure below identifies different types and sizes of particulates and how it affects the human body.

Aerosols and

Particles

Medical implications

----Liquid : Mist --------------►

----Solid: Fume ---►

◄-------Spray ----------------

◄------Particulates ----------

.01

◄ --Oil smokes ---►

◄------------Cement dust -----------►

--Fly ash ---------------------- ◄ ---------------

---Tobacco smoke --►

◄ --------------- Coal dust ---------------►

◄ --Pollens -------------►

◄-Atmosphere/Airborne--► inhalable particulates

◄-Wood .►

Dust

◄-Textiles --►

Dust

--------Respirable pm ---------►

(inhaled & penetrates the lungs)

--Thoracic pm ------------------------►

(inhaled & penetrates the larynx/throat)

---------------------------Inhalable pm ------------------►

(inhaled via the nose and /or mouth)

0.1 1 10

Particle matter (pm) diameter μm

100

Figure 1-2: Particulates and diameter size

1000

EVM Series User Manual