Air pollution sensor

Benefits

GasPlug technology (Patented)

A key aspect of this innovation is our patented smart gas cartridge system, (Spanish patent ES28855799B2 ‘Equipment for measuring gases and environmental parameters’ and applied for extension to Europe, USA, Australia, Japan, India, China, South Korea and Brazil).

The revolutionary cartridge system, designed by Kunak engineers, allows the replacement of the pollutants at the customer’s convenience. Because all cartridges are the same size, they fit into any available slot in the Kunak AIR stations.

You no longer need to send your instruments back to the factory for calibration. 

Inside each cartridge, the sensor is installed in the electronics, where data such as type, age and factory calibration are stored. So when you insert a new cartridge, the system reads the information, automatically configures itself and starts sending data almost immediately.

Select the pollutants you need to measure. If project characteristics change, order the new cartridges you need. When you receive them, simply pull out the old cartridge and insert the new one.

Quick and easy.
Insert the new cartridge and start measuring.

Range of pollutants

What we do different

QC/QA manufacturing process and Standard Operation Procedure

QC/QA manufacturing process (Factory)

1. Sensor selection: Best-in-class sensor selection among all OEM sensors.
2. Characterisation: Each sensor is characterized across the full range of temperature and humidity in the laboratory. Once characterized, specific Kunak onboard algorithm [<>] is applied to each sensor independently to correct the influence of environmental conditions.
3. Calibration: Kunak calibration against reference standards.
4. Validation: Field sensor validation.

–> Kunak calibration certificate

Standard Operation Procedure (Field)

5. Field deployment: initial verification and/or calibration/correction if required.
6. Operation and maintenance: Kunak AIR Cloud allows to perform remote network operation & maintenance. A calibration tool is available to calibrate or correct the cartridges remotely following the Kunak SOP guidelines.
7. Cartridge replacement: once the sensor reaches its end of life, cartridges are returned to Kunak and the electronics are recycled to build new cartridges.

Kunak onboard algorithm [<>]

Kunak embedded algorithm calculates the concentrations in ppb or μg/m3 locally and in real-time, not requiring any external reference data to calculate gas or particle concentrations.

Kunak algorithm corrects the interferences and artifacts typically found in raw data, compensating environmental effects like temperature, humidity, and pressure (depending on the cartridge), as well as cross-sensitivities using onboard data. Hence, Kunak algorithm compensates and mitigates all the effects derived from the different ambient conditions that the sensors will be exposed to.

Processing Level (*) of Kunak AIR stations 2A: gas concentration in μg/m3 or ppb, derived from onboard sensors, corrected for interferences based on the measurement principle and/or T/RH effects using onboard data.

(*) Schneider, et al., (2019). Toward a unified terminology of processing levels for low-cost air-quality sensors.

Standard Operation Procedure (SOP) guidelines

How Kunak AIR stations can be calibrated or corrected?

Due to the high complexity and variability among different applications, Kunak offers the possibility to either calibrate or correct the sensor drift and even combine both options to get the most reliable data with the highest accuracy.

Below are defined the processes to maintain maximum sensor accuracy:

• Calibration: The calibration consists of adjusting the sensor response based on the relation between a reference concentration value and the concentration measured by the sensor itself, obtaining an exact uncertainity of the sensors. Kunak AIR stations offer performance levels close to reference standards, providing reliable, accurate data according to Class 1 of the European CEN/TS 17660 and traceable data to international recognised standards (European Directive 2008/50/EC and USEPA 40 CFR Part 53).
• Correction: The correction consists of adjusting the sensor response withouth using any external reference data. The correction reduces the error, mitigating the drift of the sensor, however, it does not allow to calculate the exact measurement uncertainity.

Kunak Calibration & Verification

There are two types of calibration for cartridges, which can be used as verification steps as well:

A1. Calibration through co-location with reference station: calibrate the Kunak AIR station against data provided by reference instruments.

Gas cartridges: only two points are required, baseline and span (sensitivity) calibration.

Particle sensor: apply a calibration factor calculated using reference data.

A2. Certified calibration gas cylinder (ISO 6141, NIST) connected through gashood (only in gas cartridges): calibration using a gas cylinder and a gashood (see Gashood Accessory) connected to the Kunak AIR station similar as calibration protocol for reference instruments. Only two points are required: baseline and span (sensitivity).

Kunak correction

If reference data is not available, Kunak offers the possibility to mitigate the drift in the cartridges by conducting:

B1. Baseline correction without reference (only in gas cartridges): select a background level to correct the baseline based on historical data.

B2. Automatic Baseline Correction (ABC): only in CO2 and CH4 cartridges. When the cartridge detects a difference between the environmental gas background and the known CH4 and CO2 actual background, a self correction is is initiated, adjusting the cartridge parameters to align the known background concentration.

B3. MCERTS certification (only particulate matter sensor): the Kunak AIR Pro PM sensor got the MCERTS certification for Indicative Ambient Particulate Monitors. All PM sensors are delivered with the PM factors obtained in the MCERTS certification.