Atmospheric CO2

2020 update: CO2Vking v4, portable carbon dioxide meter, designed for cavers !

CO2Vking was designed by and for speleologists, as no other commercially available device is adapted to the harsh environment of dust, humidity and mud in caves.

The solid, thick 3d-printed housing is protecting sensors and electronics during exploration or research.

CO2Vking is marking the end of complications by uncompensated metering, energy greedy electrochemical or lamp-fed cells and imperfections due to warm-up.

This new generation of CO2-measurement is temperature, pressure and humidity compensated, thanks to a factory calibrated 0-5% or 0-20% gold plated, tuned narrowband NDIR CO2-sensor with PTFE filter membrane, which is a long-life, maintenance-free, fast, ultra-low energy and low budget sensor.

The high-definition climatology sensors are measuring temperature, barometric pressure, temperature and relative humidity.

The ultra-small CO2Vking model 4 is only the size of a vape cigar. It can be fitted with additional gas sensors, optional logging, wireless communication for device setting or data retrieval.

The slider power switch of the CO2Vking model 4 is hidden under the removable lid - annex hook, together with the easily swappable Li-ion battery.

Reverse polarity protection and one-key membrane button permit fool-proof operation.

The double measurement chamber is protected by a particles filter.
A rubber CO2 sensor holder is keeping the sensor safe against any impacts, while keeping the inlet small enough to pass the air imediately into its NDIR cell. The outer measurement chamber is used by the other sensors for temperature, pressure and humidity probing, avoiding condensation risks.


A CO2Vking-3 shipped in 2019. It's got the french colours,
the Belgian Red Devils red color dominating for the Drasj Nationale on the 21th of July!

CO2Vking model 3 - After sliding the protected power-switch, the instrument is operating in fool-proof mode and can be controlled by two membrane push buttons. No need to touch any button at all, as the unit’s large display is alternatively showing battery voltage, temperature, pressure, humidity, gas level and the depth at which the maximum concentration has been found.

At startup and on reset, a full self-test cycle will be performed automatically. Buzzer alarm beeps on startup and to indicate presence of CO2 gas concentrations higher than 0.5%. As the buzzer can be annoying in caves and may be stressing team mates, it can be switched off.

The BMS battery management system takes care of energy by following up the internal lithium-polymer battery voltage, warning the user to charge or switch the pack, or to use an external power bank which can be connected through the hot-swap micro-USB port. This port is also being used to recharge or top up the internal battery.

Specs sheet (EN)User manual (EN) Notice d'utilisation (FR)

To achieve great things, two things are needed: a plan, and not quite enough time.
(Leonard Bernstein)

CO2vKing Project status : model 4 release v1-2-28

Package contents

Model 3

Model 4




More Lab.vKîng projects...

Cave climate monitoring station 2017 in Aven de la Forestière
Prototype 9.0.4 of Co2vKing, our smallest CO2-meter, waiting for its 3D-printed jacket before its departure underground in 2015...


Where possible, instruments, lab equipment, battery chargers and lights are running on green energy. Prototypes are built from biodegradable 3D print filament and materials respecting our planet. We're using Rohs lead-free solder. We're also trying to avoid needless courier services between suppliers w'd like to buy from here in France and, their warehouses or country of production... far away !

Get your web site running on green energy!

All websites hosted by Speleo.EARTH, Speleo.TV and are placed on servers that solely run on power from wind turbines. This is our contribution to a greener environment.


Less CO2 emission allowances with TheCompensators