Particles vs. Gases: Choosing the Right Sensor Is the Real Key
When we talk about air pollution, what comes to mind might be smog, dust, unpleasant odors, or even the alarming red digits on an air quality monitor. But in the field of sensor technology, air pollution is far from a single concept. It is, in fact, a combination of two fundamentally different types of pollutants:
Particulate Matter and Gaseous Pollutants.
These pollutants differ not only in how they are produced and how they affect health, but also in the technologies required to detect them. Failing to understand what type of pollution you're dealing with can lead to choosing the wrong sensor—ultimately compromising your monitoring accuracy.
1. Two Types of Air Pollutants: Particles & Gases
Air pollutants generally fall into two categories:
• Particulate Matter (PM)
This includes familiar terms like PM2.5 and PM10—tiny solid or liquid particles suspended in the air, primarily generated by:
● Construction dust
● Vehicle emissions
● Industrial discharge
● Smoke or combustion
Gaseous Pollutants
These include CO₂ (carbon dioxide), HCHO (formaldehyde), and TVOC (total volatile organic compounds). Unlike visible dust, these pollutants:
● Are invisible and often odorless
● Originate from breathing, combustion, building materials, furniture, and household products
● Have long-term impacts on human health
A complete guide to selecting PM and gas sensors for indoor air quality—formaldehyde, CO₂, TVOC—tailored by use case and device application.
Particulate Sensors: Using Light to See the Invisible
TEMTOP's self-developed 4th-generation PM sensors are based on laser scattering (MIE scattering) technology. When particles pass through the laser beam, they scatter light. By collecting and analyzing this scattered light, the sensor can calculate concentrations of PM1.0, PM2.5, PM10, and TSP.
Technical Highlights:
● Real-time response across multiple PM sizes
● Built-in inversion algorithm for better interference resistance
● Widely adopted in TEMTOP devices such as M10+, M100, and M2000—trusted by over 1 million users globally
Gas Sensors: Tailored Detection for Each Pollutant
• Carbon Dioxide (CO₂)
Source: Breathing and combustion
Impact: Cognitive decline and reduced focus above 1000 ppmTEMTOP employs two mainstream technologies:
● NDIR (Non-Dispersive Infrared) — e.g., Senseair S8, known for fast response
● Photoacoustic Spectroscopy — e.g., Sensirion SCD41, ideal for battery-powered portable devices due to low power consumption
Formaldehyde (HCHO)
Source: Building materials, adhesives, plywood
Impact: Classified as a Group 1 carcinogen by WHOTEMTOP uses electrochemical sensors, which detect concentration via chemical reactions generating electrical signals. These sensors are reliable and widely applied in household devices like M10i and LKC1000.
TVOC (Total Volatile Organic Compounds)
Source: Cleaners, paints, air fresheners, furniture
Feature: A chemically complex group with varying componentsTEMTOP offers two detection strategies:
1. MOX (Metal Oxide) Sensors such as SGP40, ideal for trend tracking
2. Cross-sensitivity Inversion Algorithm, using HCHO sensor data to estimate a TVOC index
4. Choosing Sensors by Scenario: Practical Recommendations
Home Renovation | Clean Living Starts at the Source
Key Concerns: Hidden emissions of formaldehyde and VOCs from new furniture, flooring, adhesives, and paint—often lasting for months.
Why It Matters: These invisible and odorless pollutants can accumulate indoors, increasing the risk of respiratory irritation, allergies, and long-term health effects.
Recommended Setup:
● Electrochemical HCHO sensor for precise formaldehyde detection
● MOX TVOC sensor for continuous monitoring of volatile compound trends
Suggested Models: M10i / LKC1000s / M10+
Classrooms & Offices | Breathe Better, Focus Better
Key Concerns: Elevated CO₂ levels in crowded, enclosed spaces due to insufficient ventilation, leading to fatigue and reduced cognitive performance.
Why It Matters: Studies show cognitive function can decline significantly when CO₂ levels exceed 1000 ppm, especially in learning and work environments.
Recommended Setup:
● NDIR CO₂ sensor (e.g., Senseair S8) for accurate real-time monitoring
● Optional: Photoacoustic CO₂ sensor (e.g., SCD41) for low-power applications
● Laser PM sensor to monitor dust, allergens, and other particulates
Suggested Models: M2000 / M100 / M10+ / C10 2nd / C1 / C1+P2
Portable Monitoring | Air Quality in Your Pocket
Key Concerns: The need for reliable, on-the-go monitoring—whether in taxis, hotel rooms, airplanes, or field inspections.
Why It Matters: Portable use demands compact size, energy efficiency, and consistent performance in varied environments.
Recommended Setup:
● Photoacoustic CO₂ sensor (e.g., SCD41) for ultra-low power and high accuracy
● Miniature laser PM sensor to capture real-time particulate levels
Suggested Models: M10+ / C10 2nd / C1 / C1+
Industrial & Lab Environments | Precision You Can Trust
Key Concerns: High-accuracy particulate measurement in controlled or critical environments such as production lines, R&D labs, and cleanrooms.
Why It Matters: Accurate air quality data is essential for safety compliance, quality control, and research integrity.
Recommended Setup:
● High-sensitivity PM sensors (e.g., PMD series) for stable and precise readings
● Optional: Multi-channel PM analysis (PM1.0 / PM2.5 / PM10) for size distribution insight
Suggested Models: Airing2000 / PMD351 / PMD331 / PMD371
5. Final Thoughts: Sensor Selection Is About Understanding, Not Just Hardware
In air quality monitoring, no single sensor can detect all pollutants effectively. Behind each use case lies a complex decision-making process involving trade-offs in health impact, measurement accuracy, power consumption, device size, and cost.
At TEMTOP, we believe:
“Sensor selection isn’t about stacking specs—it’s about understanding your application.”
Before choosing a sensor, ask yourself:
1. What pollutant am I trying to address?
2. Do I need real-time alerts or long-term trend data?
3. Which sensor setup delivers the most valuable information in my use case?
Only when technology and context align can air monitoring truly protect health—beyond just showing numbers on a screen.
