Smell bell units for odour monitoring and water quality
Your essential solution for reliable odour monitoring
When it comes to odour monitoring, guesswork isn’t enough.
Smell bell units, or smell bells, provide accurate, repeatable sensory testing to help you detect odour issues early, protect water quality and stay compliant with regulatory standards.
They are widely used by water companies, food and beverage manufacturers, bottling plants and industrial sites to identify taste and odour problems before they escalate.
Smell bell units help you meet odour monitoring requirements effortlessly, reducing the risk of fines, customer complaints, reputational damage and failed audits.
What is a smell bell?
In simple terms, a smell bell unit is primarily used in the water treatment process to conduct sensory tests on water quality.
The process involves heating a sample of water before spraying it inside of a bell jar to concentrate any potential odours for assessment by trained personnel.
Whilst it’s simple in design, it’s a tried and tested method which helps operators detect taste and odour issues – which might be intermittent or at very low concentrations, that a taste panel in a standard lab setting might miss.
Odours can be an early indicator of problems in a water source, including decaying organic matter, changes in source water quality, operational issues in treatment processes or chemical contamination – even if such contaminants are not immediately harmful to health.
Using a smell bell for this kind of sensory assessment is often a screening step before more detailed laboratory analysis is performed.
Primarily used by water companies, smell bell units can be useful for other industries, such as food manufacturers, bottling plants and chemical plants, for odour monitoring and detection.
The benefits of smell bell units
Early detection of water quality changes
Smell bells identify subtle shifts in water quality at an early stage and offer a hands-on way to confirm changes that process instrumentation might overlook, giving you an added layer of confidence and control in your monitoring process.
Prevent complaints before they happen
Early detection of odour issues helps you act quickly, maintain customer confidence and avoid negative feedback.
Protect health and safety
Uncontrolled odours aren’t just unpleasant – they can signal gases, including some that could potentially be harmful. Smell bell units provide early warnings to keep your team, your customers and the environment safe.
Safeguard your reputation
Show customers, regulators and other stakeholders that you take your responsibilities seriously.
Support regulatory compliance
Smell bells help water companies meet their Outcome Delivery Incentives (ODIs) and help other industries comply with environmental obligations.
Simple installation and operation
Our smell bell units are supplied as a packaged plant with straightforward plug and play set up.
Why choose IWS M&E for your smell bell units?
Over two decades of proven water sector experience
Established in 2004, IWS M&E has continually expanded its capabilities and reputation over the last 20 years. As specialists in mechanical and electrical engineering, covering water and wastewater asset delivery, project management and design, we support every stage of the water cycle. Our services are cost‑effective, technically robust and tailored to meet each client’s unique requirements.
Accredited with the standards that matter
Partnering with IWS M&E means working with a fully accredited and compliant organisation. Our team operates to the highest water sector standards, ensuring every project is delivered safely, efficiently and to an exceptional quality. Explore our accreditations to learn more about our commitment to best practice.
Recognised for innovation and impact across the sector
Our understanding of the challenges facing the water sector has positioned us as a trusted partner in delivering solutions that make a difference. Collaborative projects with organisations including Wilo UK and Anglian Water have been celebrated across multiple awards schemes for their ability to address critical sector needs, highlighting our ability to deliver innovative, measurable results that make a meaningful impact.
Strengthened by South Staffordshire Plc Group
As part of South Staffordshire Plc, a Group that owns and operates two regulated water companies, IWS M&E draws on deep sector experience and a wide range of specialist water services. This foundation enables us to deliver reliable, proactive solutions for clients, supported by a Group with a long track record of delivering essential services and understanding the challenges faced by the water sector.
Smell bell units | FAQs
Smell bell units draw water through an inlet, heat it, and convert it into a fine vapour. This mist rises into the bell chamber, where the operator places their nose to assess any changes in odour. The human nose is highly effective at detecting solvents, chemicals, and other contaminants, making this a simple yet reliable manual check of water quality.
The units are designed to detect chemical-based odours and changes from the baseline – such as solvents, diesel, fuel and other potential pollutants that may enter the watercourse.
Smell bell units are a self-service testing method. They are typically used as part of operational checks carried out routinely by an organisation, with testing recommended every one to two hours to confirm that water quality remains consistent. Smell bells can also complement the organisation’s existing water monitoring procedures, providing an additional level of robust quality control.
After testing, results should be recorded on a checklist noting the date, the operator and whether the assessment was satisfactory or any odours were detected. Organisations generally record their findings using their existing documentation or reporting formats. We recommend clients keep a record of their tests for three to five years.
You can use a smell bell unit with either water from its raw source, or with treated water. You can have multiple units so they can be installed at your chosen water source.
Yes – each unit requires a 32Amp feed/socket suitable for a commando plug.
Yes – smell bell units are packaged plant and installation is a simple ‘plug and play’ concept. We also offer an installation service, if this is required.
No specialist training is required. Smell bell units arrive fully assembled. The only requirement is access to a suitable electrical socket to plug into, then simply plumbing in the inlet feed and drain.
If a suitable electrical socket is already in place, along with a water inlet feed with an accessible drain, then the unit can be plugged and plumbed in by the organisation and used immediately. Where additional installation support is needed, timescales will be confirmed by the IWS M&E team.
Installation support can be provided if required. Costs vary depending on the client’s site requirements. Get in touch with us for more information.
Pricing typically starts from £17,000, depending on the size of the system and whether a booster pump is required to address low water pressure. For a personalised quotation, please contact our team.