Introduction - Revision history

Bcmwiki: Replace trademarked term 'aethalometer' with neutral descriptor

2026-03-20T16:18:41Z

Replace trademarked term 'aethalometer' with neutral descriptor

← Older revision		Revision as of 16:18, 20 March 2026
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	=== Device Types ===		=== 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.		* '''bcMeter''' — Portable optical absorption photometer 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).		* '''eBcMeter''' — Emission measurement instrument for direct source sampling from wood-burning stoves and similar combustion sources. Uses microgram (µg) units instead of nanogram (ng).

Bcmwiki: Split sensors into core and optional hardware tables

2026-03-08T18:07:52Z

Split sensors into core and optional hardware tables

← Older revision		Revision as of 18:07, 8 March 2026
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	=== Sensors & Capabilities ===		=== Sensors & Capabilities ===

			==== Core ====

	{\| class="wikitable"		{\| class="wikitable"
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	\| Black Carbon (BC) \|\| Optical absorption at 880 nm \|\| Primary measurement		\| 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
	\|}		\|}

Bcmwiki: Update: V1/V2 naming, remove ESP32/Pi distinction

2026-03-08T13:21:10Z

Update: V1/V2 naming, remove ESP32/Pi distinction

← Older revision		Revision as of 13:21, 8 March 2026
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	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 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.

	~~=== Hardware Variants ===~~		The software is open source: [https://github.com/dahljo/bcmeter github.com/dahljo/bcmeter]

	The ~~bcMeter~~ is ~~available in two hardware variants~~:

	~~{\| class="wikitable"~~
	~~! Variant !! Platform !! Status !! Source~~
	\|-
	~~\| '''bcMeter''' (current) \|\| ESP32-S3 \|\| Production \|\| Closed source (CC BY-NC 4.0)~~
	\|-
	~~\| '''bcMeter-dev''' \|\| Raspberry Pi / Linux \|\| Reference implementation \|\|~~ [https://github.com/dahljo/bcmeter~~-dev Open source~~]
	\|}

	~~Both variants run the '''same web interface''' and provide the '''same measurement capabilities'''. This documentation applies to both — differences are noted where relevant.~~

	=== Device Types ===		=== Device Types ===

Bcmwiki: Wiki update: sync with manual and dev docs (2026-03)

2026-03-08T13:10:42Z

Wiki update: sync with manual and dev docs (2026-03)

New page

== 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.

=== Hardware Variants ===

The bcMeter is available in two hardware variants:

{| class="wikitable"
! Variant !! Platform !! Status !! Source
|-
| '''bcMeter''' (current) || ESP32-S3 || Production || Closed source (CC BY-NC 4.0)
|-
| '''bcMeter-dev''' || Raspberry Pi / Linux || Reference implementation || [https://github.com/dahljo/bcmeter-dev Open source]
|}

Both variants run the '''same web interface''' and provide the '''same measurement capabilities'''. This documentation applies to both — differences are noted where relevant.

=== 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? ===

[[File:Working principle of a bcMeter.png|300px|right]]

# 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 ===

{| class="wikitable"
! Measurement !! Sensor / Method !! Notes
|-
| Black Carbon (BC) || Optical absorption at 880 nm || Primary measurement
|-
| Source apportionment || 520 nm, 370 nm (optional) || Ångström Exponent
|-
| Temperature || BME280 / SHT4x || Internal device temperature
|-
| Humidity || BME280 / SHT4x ||
|-
| Pressure || BME280 || Barometric altitude
|-
| PM2.5 / PM10 || Sensirion SPS30 (optional) ||
|-
| Airflow || Omron D6F differential pressure || Pump flow rate
|-
| GPS || AT6668 UART (optional) || Position, altitude, speed
|-
| Connectivity || WiFi / 4G LTE-M (optional) || SIM7080G modem
|}