Tag: LCS

Review: AirGradient Open Air

Sotirios PapathanasiouLeave a comment

Having had the opportunity to get the AirGradient Open Air (Model O-1PST) at the ASIC 2025 conference in Thailand, complete with its unique engraving, I’ve spent some time with this device, and it’s clear that AirGradient is pushing the boundaries of accessible and reliable outdoor air quality monitoring. This device presents a compelling alternative to existing solutions, particularly for those seeking transparency and robust performance.

Technical Specifications O-1PST

  • WiFi 2.4GHz IEEE 802.11 b/g/n-compliant
  • Bluetooth LE: Bluetooth 5, Bluetooth mesh
  • Status LED
  • Plantower PMS5003T for PM2.5 + ENS210 for T/RH
  • SenseAir S8/S88 CO2 NDIR Sensor
  • Sensirion SGP41 TVOC/NOX Module
  • Enclosure: ASA Plastic, UV Resistant and Weather Proof
  • Mounting Options: Wall or pole mounting options
  • 4m USB-C to USB-A Cable
  • USB-C Power Connector 2A/5V
  • Certifications: CE, RoHS, REACH, FCC

Sensor Selection: A Thoughtful Approach

The Open Air features a well-considered suite of sensors designed for accurate and insightful data. For PM2.5 measurements, it utilizes the Plantower PMS5003T, a sensor known for its reliability and found in other popular monitors like the PurpleAir (though it’s important to note the PMS5003T is a similar but not identical variant).

Read More »

Key Insights from ASIC 2025 in Thailand: Bridging the Indoor-Outdoor Divide

Sotirios Papathanasiou1 Comment

The recent Air Sensors International Conference (ASIC) 2025, held in the vibrant backdrop of Thailand, offered a profound opportunity to delve into the evolving landscape of air quality monitoring. As an attendee, several key themes emerged that highlight both the progress made and the remaining challenges in our quest to understand the air we breathe.

The Indoor-Outdoor Air Quality Discrepancy

One striking observation from the conference was the apparent disparity in research emphasis between indoor and outdoor air quality monitoring. While outdoor environments have benefited immensely from the widespread adoption and scrutiny of low-cost air quality monitors, indoor spaces appear to lag in comparison. The primary reason for this imbalance lies in the availability of robust reference instrumentation. Governments worldwide have invested in publicly air quality stations equipped with reference-grade instruments, providing invaluable benchmarks for normalization and validating low-cost sensors in a variety of outdoor conditions. This has not only accelerated the development of accurate low-cost monitors but also fostered the creation of sophisticated correction algorithms.

Read More »

Are Low-Cost Sensors Random Number Generators?

Sotirios Papathanasiou5 Comments

Low-cost sensors aka LCS are commonly used in an effort to measure air pollutants like particulate matter all around the world, indoors and outdoors. Their low price has driven a lot of interest from many communities. Academics, experts, and consumers have embraced them because they are cheap to get and easy to embed in an IoT solution.

Countless air quality monitors use low-cost sensors (mostly from China) and although they are great as educational tools, their low accuracy leads to wrong conclusions most of the time.

Wrong conclusions are as bad as misinformation or fake news. Air pollution doesn’t kill instantly (most of the time) and it doesn’t create severe health issues in the short-term, but after an extended period or at least when we notice the consequences. One exception is carbon monoxide (CO) as it can kill people instantly and this is the reason we don’t see many low-cost CO sensors. There are some regulations that protect the consumers. Moreover, companies don’t want to take responsibility by using a low-cost CO sensor because they can get sued easily by the family of a victim when the air quality monitor won’t notice the increase of the gas indoors. Liability!

Read More »