Difference between revisions of "Introduction"

Latest revision as of 19:07, 8 March 2026

Introduction

The bcMeter is an open-source optical absorption photometer designed to measure Black Carbon (BC) aerosols — commonly known as soot — in real-time. Whether you are monitoring ambient air quality in your neighborhood or measuring direct emissions from wood stoves, this device provides scientific-grade data at a fraction of the cost of reference instruments.

The device operates "headless" — it has no built-in screen. Instead, it hosts its own website that you can access from any smartphone or computer connected to the same network.

The software is open source: github.com/dahljo/bcmeter

Device Types

bcMeter — Portable aethalometer for ambient Black Carbon measurement. Designed for stationary or mobile deployment in monitoring networks, citizen science projects, and field campaigns.
eBcMeter — Emission measurement instrument for direct source sampling from wood-burning stoves and similar combustion sources. Uses microgram (µg) units instead of nanogram (ng).

How Does It Work?

Polluted air is drawn through filter paper by a pump
The filter paper absorbs black carbon (BC) particles
An LED shining at 880 nm passes through the filter; a sensor measures the attenuation (reduction in light intensity)
A separate reference channel monitors the same LED through a clean portion of the filter, compensating for environmental changes
The attenuation is converted to BC concentration (ng/m³) using Beer-Lambert law
Data is saved as CSV and displayed in real-time on the web interface

Multi-wavelength: Optional 520 nm and 370 nm channels enable source apportionment via the Ångström Exponent (AAE) — distinguishing between fossil fuel and biomass burning sources.

Sensors & Capabilities

Core

Measurement	Sensor / Method	Notes
Black Carbon (BC)	Optical absorption at 880 nm	Primary measurement
Source apportionment	520 nm, 370 nm	Ångström Exponent
Temperature / Humidity	SHT4x
Airflow	Omron D6F differential pressure	Pump flow rate

Optional Hardware

Measurement	Sensor / Method	Notes
Temperature / Humidity / Pressure	BME280	Barometric altitude
PM2.5 / PM10	Sensirion SPS30	Particulate matter
GPS	AT6668 UART	Position, altitude, speed
4G Connectivity	SIM7080G LTE-M modem	Remote data upload

@@ Line 26: / Line 26: @@
 === Sensors & Capabilities ===
+==== Core ====
 {| class="wikitable"
@@ Line 32: / Line 34: @@
 | Black Carbon (BC) || Optical absorption at 880 nm || Primary measurement
 |-
-| Source apportionment || 520 nm, 370 nm (optional) || Ångström Exponent
+| Source apportionment || 520 nm, 370 nm || Ångström Exponent
 |-
-| Temperature || BME280 / SHT4x || Internal device temperature
+| Temperature / Humidity || SHT4x ||
 |-
-| Humidity || BME280 / SHT4x ||
+| Airflow || Omron D6F differential pressure || Pump flow rate
+|}
+==== Optional Hardware ====
+{| class="wikitable"
+! Measurement !! Sensor / Method !! Notes
 |-
-| Pressure || BME280 || Barometric altitude
+| Temperature / Humidity / Pressure || BME280 || Barometric altitude
 |-
-| PM2.5 / PM10 || Sensirion SPS30 (optional) ||
+| PM2.5 / PM10 || Sensirion SPS30 || Particulate matter
-|-
-| Airflow || Omron D6F differential pressure || Pump flow rate
 |-
-| GPS || AT6668 UART (optional) || Position, altitude, speed
+| GPS || AT6668 UART || Position, altitude, speed
 |-
-| Connectivity || WiFi / 4G LTE-M (optional) || SIM7080G modem
+| 4G Connectivity || SIM7080G LTE-M modem || Remote data upload
 |}