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Measurement Principles for Gas, Particle and Process Analysis

A Practical Guide to Industrial & Environmental Monitoring
19 décembre 2025 par
Measurement Principles for Gas, Particle and Process Analysis
AAVOS International bv, Roger van Uden

Accurate measurement of gases, particles and process parameters is essential for environmental compliance, process optimization and safety. At AAVOS International, we support industrial users with advanced analyzers based on proven measurement principles, each optimized for specific components and applications.

This guide explains the main measurement principles used in modern monitoring systems and which components are typically measured with each technique.

1. Optical Particle & Aerosol Measurement

(Ambient air & emission monitoring)

Measurement principles

  • Optical scattering

  • Condensation Particle Counting (CPC)

  • Electrical diffusion charging

  • Gravimetric reference methods

Typical components measured

  • PM – Particulate Matter

  • PM1, PM2.5, PM4, PM10

  • UFP – Ultrafine Particles

  • PN – Particle Number

  • TSP – Total Suspended Particles

  • TSS – Total Suspended Solids

  • LDSA – Lung Deposited Surface Area

  • Black Carbon

  • Brown Carbon

  • Dust

  • Particles

Typical applications

  • Ambient air quality monitoring

  • Stack & emission measurements

  • Occupational exposure monitoring

  • Health impact assessments

Why it matters: Fine and ultrafine particles are regulated worldwide due to their impact on health and climate.

2. Infrared & Optical Gas Analysis (NDIR, FTIR, UV)

Measurement principles

  • Non-Dispersive Infrared (NDIR)

  • Fourier Transform Infrared (FTIR)

  • UV photometry

  • Optical absorption spectroscopy

Typical components measured

  • CO – Carbon Monoxide

  • CO₂ – Carbon Dioxide

  • SO₂ – Sulfur Dioxide

  • NO, NO₂, NOx – Nitrogen Oxides

  • SOx – Sulphur Oxides

  • O₃ – Ozone

  • N₂O – Nitrous Oxide

  • HCl – Hydrogen Chloride

  • HF – Hydrogen Fluoride

  • NH₃ – Ammonia

  • H₂O – Water

  • TRS – Total Reduced Sulphur

  • TS – Total Sulfur

Typical applications

  • Continuous Emission Monitoring Systems (CEMS)

  • Industrial stacks and furnaces

  • Waste incineration

  • Power generation

Why it matters: Optical methods provide continuous, selective and stable measurements for regulated pollutants.

3. Flame Ionization Detection (FID)

Measurement principle

  • Ionization of organic compounds in a hydrogen flame

Typical components measured

  • THC – Total Hydrocarbons

  • NMHC – Non-Methane Hydrocarbons

  • VOC – Volatile Organic Compounds

  • HC – Hydrocarbons

  • Methane (CH₄)

Typical applications

  • Emission monitoring

  • Petrochemical processes

  • Refinery and chemical plants

  • VOC compliance monitoring

Why it matters: FID remains the reference technique for hydrocarbon measurement due to its sensitivity and reliability.

4. Gas Chromatography (GC / GC-MS)

Measurement principles

  • Gas chromatography

  • GC-FID

  • GC-MS (mass spectrometry)

Typical components measured

  • BTEX (Benzene, Toluene, Ethylbenzene, Xylenes)

  • Benzene, Toluene, Ethylbenzene

  • Alcohols (Methanol, Ethanol)

  • Aldehydes (Formaldehyde, Acetaldehyde)

  • Ketones (Acetone)

  • Organic Acids

  • Vinyl Acetate

  • Siloxanes

  • Halogenated anesthetic gases

    • Halothane

    • Isoflurane

    • Enflurane

    • Desflurane

    • Sevoflurane

Typical applications

  • Process gas analysis

  • Quality control

  • Chemical production

  • Medical and pharmaceutical environments

Why it matters: GC provides compound-specific identification, essential where selectivity is critical.

5. Electrochemical Sensors

Measurement principle

  • Electrochemical reaction at sensor electrodes

Typical components measured

  • CO – Carbon Monoxide

  • NO, NO₂

  • SO₂

  • H₂S – Hydrogen Sulfide

  • NH₃ – Ammonia

  • O₃ – Ozone

  • Cl₂ – Chlorine

Typical applications

  • Safety monitoring

  • Confined spaces

  • Leak detection

  • Portable gas detection

Why it matters: Electrochemical sensors are compact, cost-effective and ideal for local safety monitoring.

6. Thermal Conductivity & Paramagnetic Analysis

Measurement principles

  • Thermal conductivity detection

  • Paramagnetic oxygen analysis

Typical components measured

  • H₂ – Hydrogen

  • N₂ – Nitrogen

  • O₂ – Oxygen

  • Argon (Ar)

  • Helium (process applications)

Typical applications

  • Process gas control

  • Inerting systems

  • Hydrogen applications

  • Industrial gas production

7. Elemental Analysis (ICP-OES, ICP-MS, XRF, AAS)

Measurement principles

  • Inductively Coupled Plasma (ICP)

  • X-ray Fluorescence (XRF)

  • Atomic Absorption Spectroscopy (AAS)

Typical elements measured

Ag, Al, As, Au, Ba, Bi, Br, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, Ge, Hg, I, In, K, La, Lr, Mn, Mo, Nb, Ni, P, Pb, Pd, Pt, Rb, Re, Rh, Ru, Sb, Se, Sn, Sr, Ta, Te, Ti, Y, Zr

Typical applications

  • Environmental monitoring

  • Soil and water analysis

  • Industrial quality control

  • Heavy metal compliance

8. Persistent Organic Pollutants (POPs) Analysis

Measurement principles

  • High-resolution GC-MS

  • Sample pre-concentration

Typical components measured

  • Dioxins / Dioxines

  • Furans

  • PCDD

  • PCDF

  • POPs

Typical applications

  • Waste incineration

  • Environmental impact studies

  • Regulatory compliance

9. Physical & Process Parameters

Measurement principles

  • Thermal sensors

  • Capacitive sensors

  • Flow measurement

  • Optical turbidity sensors

  • Acoustic measurement

Typical parameters measured

  • Temperature

  • Relative Humidity (%RH)

  • Airflow

  • Turbidity

  • Noise

  • pH (Acidity)

Conclusion: Choosing the Right Measurement Principle

Each measurement principle has its own strengths, limitations and ideal applications. Selecting the right technology depends on:

  • The components to be measured

  • Regulatory requirements

  • Process conditions

  • Required accuracy and response time

AAVOS International supports customers in selecting, integrating and maintaining the most appropriate analytical solutions — from ambient air monitoring to complex industrial process analysis.

👉 Contact AAVOS to discuss the right measurement technology for your application.

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