Project Highlights:


  • Developing a new, cutting edge and internationally needed atmospheric observational capability.
  • Working with leading international industrial partners and sensor manufacturers.
  • Working in a cutting edge area with direct real world implications and potential impacts.


A new NH3 monitoring methodology is needed in the UK and internationally. This is needed to address emerging international scientific and regulatory questions. Small, accurate low-cost instruments suitable for ambient NH3 observational studies are not currently available. Suitably sensitive instruments with the required fast response (minutes) are either too large, expensive or difficult to deploy. Current routine systems have low time resolution (weeks) are large and manpower intensive. Without a new high resolution routine capability (spatially and temporally) a detailed evidence base for NH3 distribution and emissions is not possible.

The UK met current NH3 commitments narrowly with future targets a concern when changes in agriculture, transport and waste sectors are considered. In order to meet international obligations, a reliable evidence base is needed. Additionally the current emissions landscape is poorly mapped See figure 1) and any mitigation policy difficult to effectively assess. Increased monitoring will help identify effective controls and technologies. This would have significant impacts on reducing future monitoring costs (both scientific and compliance driven) and increasing efficiency and effectiveness of control implementation.

Developing the capability for routine and low cost (i.e. potentially widespread) NH3 measurements in the UK and globally (emissions are controlled nationally but are transboundary) will have broad implications. Including e.g. in Africa where increasingly industrial agricultural practices are of international significance. This new methodology needs to be robust, relatively low-cost, easy to operate in arrange of environments and operate at ambient levels.

This project aims to meet this need by demonstrating that a relatively low-cost multi-capability sensor network approach for measurement of NH3 can be made overcoming the challenge of the low limits of detection required and secondly a stand-alone instrument can be designed for use in real world applications where there is a significant capability gap.

In this project selected small sensor NH3 technologies will be co-developed with a systems design approach to develop a cutting edge NH3 observational capability for routine operation at ambient levels. NH3 sensors will be combined in a small sensor network approach. These will be used in a series of real-world tests with project partners.


Figure 1: 2007 NH3 distribution (https://uk-air.defra.gov.uk/networks/network-info?view=nh3). Showing the current relatively low resolution UK capability.


A number of miniature industrial NH3 sensors with relatively high limits of detection are available. Significant gains for individual technologies can be made with a systems approach (based on multiple incremental improvements across the sensor system) which can improve limits of detection for these sensors as shown in earlier studies. Use of these improved sensors in groups as sensor arrays or linked networks will be used to measure NH3. These networks will be flexible and cascading with larger numbers of low-cost lower resolution sensors used to expand observational footprints and a smaller number of high resolution sensors to provide high resolution capability and transfer calibration across the network. To achieve this a mix of industrial NH3 sensors have been selected for use: metal oxide semiconductors (MOS. (Figaro Inc, USA), electrochemical cells (EC. Alphasense Ltd, UK) and a minituarised IR spectrometer prototype (Sensair AB, Sweden).


Training and Skills

Students will be able to take part in components of the Cranfield MSc provision. Particularly the “Atmospheric Emission Control and Technology” and “Atmospheric Informatics and Emissions Technology” MSc modules (each taking up to 5 days each) where available.

2 day foundation course on atmospheric chemistry and composition provided by supervisory team or selected Cranfield research scientists.

5 day work placement on the fundamentals of instrument calibration hosted by FAAM.


Year 1.

  • T1. Benchtop assembly builds: Selected components will be integrated into prototype benchtop instruments for laboratory testing.

Year 2.

  • T2. Prototype development: Laboratory test assemblies refined for ambient operation and tested with a synthetic gas matrix in a range of environments.
  • T3. Laboratory validation: MOS, EC and NDIR performance quantified.

Year 3.

  • T4. IR cell chracterisation: observed transmission across selected wavelength band compared with the HITRAN database. Intrinsic instrument noise and lower limit of detection calculated.
  • T5. Real world prototype testing with project partners.

Partners and collaboration (including CASE)

Alphasense Ltd. UK. Internationally leading sensor manufacturer for both industrial and ambient sensing. Primary contact: Dr John Saffell. Role: Technical Director. Email: jrs@alphasense.com. Website: http://www.alphasense.com/

Sensair AB. Sweden. Leading sensor manufacturer for gas alarms, the transport sector and for indoor and outdoor air quality. Contact: Dr Hans Martin. Head of Research and Development. jrs@alphasense.com. https://senseair.com/

Johnson Matthey. Global. Leader in sustainable technologies in natural resources and health fields. Contact: Olivier LeRoux. Business Development Manager. Olivier.LeRoux@matthey.com. https://matthey.com/

Environment agency. UK. Governmental body with responsibility for protection of the environment. Contact: Dr Rob Kinersley. Principal Scientist. rob.kinnersley@environment-agency.gov.uk. https://www.gov.uk/government/organisations/environment-agency