Online Gas Odorant Monitor

Natural Gas, Hydrogen & Biomethane

Natural gas is odorless, therefore odorant is added to gas networks supplying homes and businesses. Odorant is also required for biomethane and hydrogen networks. The smell of the odorant helps alert people to a potential gas leak or issues with appliances.

It is vital to ensure that the correct amount of odorant is added to the network and that the odorant remains present at the required concentration over the whole length of the gas grid. If too little odorant is added, gas leaks may not be able to be detected, meaning that peoples’ lives could be put in danger. Too much odorant could create a false sense of alarm, but also an additional cost for gas networks and their customers.

Online 24/7 odorant monitoring

BioSpec Rhino is an automated online device that accurately monitors the individual components of odorant and odorant blends used in the UK, Europe, and worldwide. It provides a real-time view of the odorant composition on the gas network and provides assurance that each component of the odorant is present at the required concentration.

Currently, manual checks are carried out at different points on the gas network by trained Rhinologists with samples also being sent to specialised laboratories. This process only provides a subjective snapshot , or having to wait several days for lab results to be returned.

We have used our expertise in optical spectroscopy measurement techniques to develop an automated instrument that monitors the gas odorant level 24/7. This technology provides continuous assurance that safety regulations are complied with, a more cost-effective monitoring approach compared to manual and laboratory measurement, and the potential to optimise the volume of odorant that is injected to the gas grid.

Net-zero gas grids

As well as natural gas, many gas networks also carry other forms of gas such as biomethane and hydrogen in order to help decarbonise the gas grid. BioSpec Rhino can accurately measure odorant levels in natural gas, biomethane and hydrogen which makes it a future proofed solution.

Biogas contains many impurities which must be removed before biomethane is injected onto the gas grid. Hydrogen from industrial sources can also have impurities. As well as odorants, BioSpec Rhino also measures a range of other components such as hydrogen sulphide, ammonia, ketones and terpenes. These components can impact the grid integrity or result in non-compliant gas reaching customers. For example, terpenes are common volatile organic compounds from the digestion of food waste and can mask the smell of the odorant to the human nose. Therefore, it is very important to also measure these components in the gas as well as the odorant itself.

Range of Benefits


BioSpec Rhino measures all common odorants such as TBM, DMS, THT and others. By individually measuring each component within an odorant blend, the instrument can also monitor for odorant fade at the individual component level.


Online monitoring provides a cost-effective solution compared with subjective manual sampling by Rhinologists and using laboratory testing. Furthermore, by providing continuous assurance that the right level of odorant is reaching the extremities of the grid, there is the potential for savings by using less odorant at the injection point and avoiding over odorization on other parts of the network.


Health and Safety

Online and continuous assurance that the correct level of odorant has been added to the gas ensures that a safe product is delivered to the customer. Furthermore, the device measures other contaminants that could be present in gas that may impact the integrity of the network, such as hydrogen sulphide, or components like terpenes that can mask the smell of the odorant.


As well as natural gas, the same product can be used for biomethane and hydrogen gas or blends. The technology is therefore fully suitable as networks increase the amount of renewable gas on their grids or move to 100% renewables.