Precision measurement.
For every cloud.
For every community.
Next-generation atmospheric instruments for climate science.
The HCCNC
The Horizontal Cloud Condensation Nuclei Counter is our first instrument — a device that generates supersaturation conditions at close to those found in real clouds. Developed at ETH Zurich, it addresses a measurement limitation that has been documented in the atmospheric science literature for over two decades.
The conditions inside the instrument are not the conditions inside a cloud.
For over two decades, atmospheric researchers measuring cloud condensation nuclei have relied on essentially one commercially available instrument design. Its operating limitations are well documented and widely acknowledged in the peer-reviewed literature.
The Heating Bias
Conventional cloud condensation nuclei counters, such as the Streamwise CCNC, use a heated column to generate supersaturation. With a sample drawn at 25 °C, the column operates at roughly 30–52 °C — well above the range in which real cloud droplets form. At these elevated temperatures, semi-volatile compounds evaporate from the particles, biasing the measured cloud condensation nuclei activity.1, 2, 3
The Low-Supersaturation Blind Spot
Measurements below approximately 0.13 % supersaturation — and in some cases below 0.2 % — are widely considered unreliable on instruments of this design.4, 5, 6 This operating floor makes it difficult to study highly hygroscopic particles, such as Southern Ocean aerosols (κ ≈ 0.92) larger than 100 nm, which activate well below that threshold.
Supersaturation stabilization bottlenecks
Because supersaturation is established with thermoelectric heaters, which respond slowly, thermal lag occurs when stepping between supersaturation levels or beginning a new supersaturation scan cycle. Data collected during these equilibration periods — up to the first three minutes of each step (could vary with different device) — must be excluded from analysis, that means discarding crucial data.
The Horizontal Cloud Condensation Nuclei Counter (HCCNC).
Dynamic Temperature Range
The HCCNC generates supersaturation across a temperature range of 4 °C to 40 °C — the first cloud condensation nuclei counter validated to operate across this range.6 Development is underway to extend this further, which would allow researchers to study how temperature governs particle activation and gas–particle partitioning across a broader envelope.
Low-Supersaturation Capability
Precise thermal control and a residence time of up to 24 seconds allow the HCCNC to generate supersaturation levels reliably down to 0.05 %.
Speed Without Compromise
No data is lost during the supersaturation cycle. On top of that, the supersaturation cycle resets up to seven times faster than conventional cloud condensation nuclei counters. A new "flash scan" mode sweeps 0.05 % to 0.8 % supersaturation in under a minute.
Modular Design
Opening the HCCNC chamber takes three steps. After a long campaign, clearing residual material is as simple as opening a water bottle: open the chamber, replace the filter paper, close it. No specialist required — which saves time and cost. So you can focus on research not repairs.
How the HCCNC works.
The HCCNC operates on the principle of a parallel-plate thermal-gradient diffusion chamber.
Developed through computational fluid dynamics simulations, the design optimises laminar flow stability and precise temperature regulation to achieve stable, controllable supersaturation across a wide operating range.
Since temperature gradients drive supersaturation in a cloud condensation nuclei counter, each plate is controlled precisely and independently to provide stable and direct command over the internal supersaturation.
New science,
made measurable.
The HCCNC's operating range opens measurement regimes that have not been accessible with instruments of the conventional streamwise design. A few examples:
Low-Temperature Capability
Low-Supersaturation Capability
High-Supersaturation & Dynamic Residence Time
Validated by science.
Recognised by the field.
Peer-Reviewed Publication
Published in Atmospheric Measurement Techniques (EGU), 2025 — a full instrument characterisation validated against Köhler theory.6 A second publication demonstrating the HCCNC's capabilities in analysing complex organic compounds (such as levoglucosan) is currently in preparation.
Patent Filed
The patent for HCCNC has already been filed.
ETH Pioneer Fellowship
Awarded the prestigious ETH Zurich Social Impact Pioneer Fellowship to develop the instrument toward a deployable device.
Industry Recognition
An unsolicited licensing inquiry received from established industry incumbents, acknowledging the HCCNC's demonstrated performance advantage.
Active Customer Interest
Two researchers are in active discussions to purchase the instrument. Two research groups — one in Asia, one in Europe — are collaborating with us on scientific projects.
The people behind the instrument.
