Cairpol Odour Monitoring


Odour monitoringEnvirosafe Ireland provide Cairpol Odour Monitoring Systems for Wastewater Treatment Plants.

CairTub allows the easy deployment of autonomous measurement points virtually anywhere. The system can be used in harsh weather conditions. It is also the ideal tool for low cost studies for the optimisation and setting-up of fixed air quality monitoring stations.

With an autonomy of 21 days, these measurement systems consist of a stainless weather protection case for exterior use even in bad weather conditions and the micro-sensor CairSens, adapted to the low concentration measurement of pollutants to be measured (O3/NO2, H2S and Sulphur compounds, NH3) or other compounds of specific interest.


Initially designed for oxidising (O3 / NO2) monitoring to warn asthmatics of real-time pollution levels, Cairpol sensor range has been developed further to cover industrial applications including the measurement of sulphur compounds and H2S (typical olfactive nuisances from waste water treatment facilities) and ammonia (characteristic odour from decomposition processes).



Odour monitoringCairNet is a simple and efficient way to monitor processes and plant surroundings via a wireless communicating network and autonomous (solar panel and battery). CairNet surveys fugitive emissions of toxic gases or odourous gases around waste water treatment plants (WWTP), allowing you to react quickly to gas leaks. CairNet allows the wireless survey of hundreds of measurement points within a 200m radius of the wireless receiver for a much efficient installation cost.


Every CairNet measurement point consists of:

  • Weather protection cases in stainless steel, equipped with a miniature sensor
  • Solar panel and its battery
  • Radio communication module


Cairpol systems can be used for fugitive emissions and odour measurement on industrial sites like waste water treatment plants (WWTP), landfill, compost plant, along a street or motorway, or in any sensitive area.

Cairpol monitoring systems also offer the possibility to measure continuously pollutant levels in workshop atmospheres, houses and public buildings.


Taking into account the effects of increasing air pollution on human health, Cairpol allows new real-time measurement possibilities of pollutants (gas, odour or particulate) even at very low concentrations (ppb).

Completely autonomous and able to detect ppb pollution levels, Cairpol miniature sensors cause a great stir in the air quality monitoring world, with an installation cost level never being so low until now.

Cairpol patented technology is used in many industrial applications. One such application is wastewater monitoring, which previously was too costly with conventional monitoring systems.

With its compact, autonomous, easy to set up, sensitive and reliable sensors that can be used even in extreme conditions, the communication systems and ultra-low power consumption, Cairpol systems can be networked to provide optimal coverage and measurement of air pollution over a vast area from a single computer



  • Odour monitoring on Wastewater Treatment Plants
  • Dynamic pollution mapping
  • Ambient air pollution study
  • Indoor air quality measurement
  • Chronic exposure evaluation
  • Individual health survey
  • Boundary Monitoring



  • Simple, reliable, cost effective
  • ppb detection levels
  • No maintenance, no need for re-calibration
  • Autonomous version (solar panel)
  • Immediate operation
  • Sensor life: 1 year


GASES ANALYSED                                                            RANGE

Ozone (O3) / Nitrogen dioxide (NO2)                     0-250 ppb

Nitric Oxide (NO)                                                             0-250 ppb

Carbon Monoxide (CO)                                                 0-20 ppm

Hydrogen Sulphide (H2S)                                             0-1000 ppb / 0-20 ppm / 0-200 ppm

Methyl Mercaptans (CH4S)                                         0-1000 ppb / 0-20 ppm / 0-200 ppm

Ammonia (NH3)                                                               0-25 ppm

Sulphur Dioxide (SO2)                                                    0-1000 ppb

Formaldehyde (CH2O)                                                   0-1000 ppb

Organic solvents                                                               0-1000 ppb

Non Methane VOCs (nM VOC)                                  0-16 ppm



  • Sensitivity levels of up to 50-100 times better than current sensors on the market and providing real-time measurement data at a fraction of the cost of reference method analysers
  • Cairpol systems can be deployed quickly for fixed and portable measurement applications


Internal data logging capacity: Up to 1 year, depending on the setting.

Operating time: 24 to 36 hours when fully charged for USB versions (daily recharge for optimal use)

Power supply: 5VDC /200 mA rechargeable by USB via PC or 220V/110V with 5V adaptor (solar panel option)

Dimensions: Diameter 32 mm, length 62mm Weight: 55g

Electric standards: CEI/UL/CSA N°61010-1:2008 / EN 61010-1:2001

Output: USB or UART (Analog signal on demand)

Rating:  IP42 (IEC60529)

Storage condition: 5 to 20°C,10 to 90% RH, mbar 1013 ± 200 (psi 14,69 ± 2,90)

Operating condition: Depending on the sensor, in general -20°C to +45 °C,10 to 90% RH, mbar 1013 ± 200 (psi 14,69 ± 2,90)



The amperometric sensor consists of three electrodes: the working electrode (anode), the counter electrode (cathode) and the reference electrode. The gas to be analysed is diffused through a permeable membrane towards the sensitive electrode. Depending oo the gas, oxydation takes place at the anode, or reduction at the cathode. The electrical signal generated between the two electrodes is proportional to the concentration.



CairSens© – Cairsens is an integrated system consisting of an amperometric sensor, a dynamic air sampling with a patented filter, and an electronic circuitry which allows a direct real time display of the measured value and status complete with internal datalogging

CairTub©: Protective housing for stand-alone outdoor application, 21 days power autonomy, easy to install or move.

CairNet©: Protective housing – with wireless communication, autonomous using solar panel – for online data acquisition