Crowcon - Detecting Gas Saving Lives
24 July 2023
Molecular Property Spectrometer™ Flammable Gas Sensors

Developed by NevadaNano, Molecular Property Spectrometer™ (MPS™) sensors represent the next generation of flammable gas detectors. MPS™ can quickly detect over 15 characterised flammable gases at once. Until recently, anyone who needed to monitor flammable gases had to select either a traditional flammable gas detector containing a pellistor sensor calibrated for a specific gas, or containing an infra-red (IR) sensor which also varies in output according to the flammable gas being measured, and hence needs to be calibrated for each gas. While these remain beneficial solutions, they are not always ideal. For example, both sensor types require regular calibration and the catalytic pellistor sensors also need frequent bump testing to ensure they have not been damaged by contaminants (known as ‘sensor poisoning’ agents) or by harsh conditions. In some environments, sensors must frequently be changed, which is costly in terms of both money and downtime, or product availability. IR technology cannot detect hydrogen – which has no IR signature, and both IR and pellistor detectors sometimes incidentally detect other (i.e., non-calibrated) gases, giving inaccurate readings that may trigger false alarms or concern operators.  

Building on over 50 years of gas expertise, Crowcon is pioneering advanced MPS™ sensor technology that detects and accurately identifies over 15 different flammable gases in one device. Now available in Crowcon’s flagship Xgard Bright fixed detector and portable detectors Gasman and T4x. 

Benefits of Molecular Property Spectrometer™ Flammable Gas Sensors 

The MPS™ sensor delivers key features that provide real world tangible benefits to operator and hence workers. These include:  

No calibration 

When implementing a system containing a fixed head detector, it is common practice to service on a recommended schedule defined by manufacturer. This entails ongoing regular costs as well potentially disrupting production or process in order service or even gain access to detector or multiple detectors. There may also be a risk to personnel when detectors are mounted in particularly hazardous environments. Interaction with an MPS sensor is less stringent because there are no unrevealed failure modes, provided air is present. It would be wrong to say there is no calibration requirement. One factory calibration, followed by a gas test when commissioning is sufficient, because there is an internal automated calibration being performed every 2 seconds throughout the working life of the sensor. What is really meant is – no customer calibration.  

Multi species gas – ‘True LEL’™ 

Many industries and applications use or have as a by-product multiple gases within the same environment. This can be challenging for traditional sensor technology which can detect only a single gas that they were calibrated for at the correct level and can result in inaccurate reading and even false alarms which can halt process or production if another flammable gas type is present. The lack of response or over response frequently faced in multi gas environments can be frustrating and counterproductive compromising safety of best user practices. The MPS™ sensor can accurately detect multiple gases at once and instantly identify gas type. Additionally, the MPS™ sensor has a on board environmental compensation and does not require an externally applied correctional factor. Inaccurate readings and false alarms are a thing of the past. 

No sensor poisoning 

In certain environments traditional sensor types can be under risk of poisoning. Extreme pressure, temperature, and humidity all have the potential to damage sensors whist environmental toxins and contaminants can ‘poison’ sensors, leading to severely compromised performance. Detectors in environments where poisons or inhibitors may be encountered, regular and frequent testing is the only way to ensure that performance is not being degraded. Sensor failure due to poisoning can be a costly experience. The technology in the MPS™ sensor is not affected by contaminates in the environment. Processes that have contaminates now have access to a solution that operates reliably with fail safe design to alert operator to offer a peace of mind for personnel and assets located in hazardous environment. Additionally, the MPS sensor is not harmed by elevated flammable gas concentrations, which may cause cracking in conventional catalytic sensor types for example. The MPS sensor carries on working.  

Hydrogen (H2) 

The usage of Hydrogen in industrial processes is increasing as the focus to find a cleaner alternative to natural gas usage. Detection of Hydrogen is currently restricted to pellistor, metal oxide semiconductor, electrochemical and less accurate thermal conductivity sensor technology due to Infra-Red sensors inability to detect Hydrogen. When faced with challenges highlighted above in poisoning or false alarms, the current solution can leave operator with frequent bump testing and servicing in addition to false alarm challenges. The MPS™ sensor provides a far better solution for Hydrogen detection, removing the challenges faced with traditional sensor technology. A long-life, relatively fast responding hydrogen sensor that does not require calibration throughout the life cycle of the sensor, without the risk of poisoning or false alarms, can significantly save on total cost of ownership and reduces interaction with unit resulting in peace of mind and reduced risk for operators leveraging MPS™ technology. All of this is possible thanks to MPS™ technology, which is the biggest breakthrough in gas detection for several decades.  

How does the Molecular Property Spectrometer™ Flammable Gas Sensor work 

A micro-electromechanical system (MEMS) transducer—comprising an inert, micrometer-scale membrane with an embedded heater and thermometer—measures changes in the thermal properties of the air and gases in its proximity. Multiple measurements, akin to a thermal “spectrum,” as well as environmental data are processed to classify the type and concentration of flammable gas(es) present, including gas mixtures. This is called  TrueLEL. 

  1. Gas rapidly defuses through the sensor’s mesh screen and into the sensor chamber, entering the MEMS sensor module.​ 
  2. The joule heater rapidly heats the hot plate.​ 
  3. Real-time environmental conditions (temperature, pressure and humidity) are measured by the integrated environmental sensor.  
  4. The energy required to heat the sample is precisely measured using a resistance thermometer.​ 
  5. The gas level, corrected for gas category and environmental  conditions, is calculated and output to the gas detector. 

MPS in our Products 

Xgard Bright

Many industries and applications use or have as a by-product multiple gases within the same environment. This can be challenging for traditional sensor technology which can detect only a single gas that they were calibrated for at the correct level and can result in inaccurate reading. 

Xgard Bright with MPS™ sensor technology provides a ‘TrueLEL™’reading for all flammable gases in any multi species environment without requiring calibrationor scheduled maintenance over its 5-year+ lifecycle, reducing interruptions to your operations and increases up-time. This in turn reduces the interaction with the detector resulting in a lower total cost of ownership over the sensor life cycle and reduced risk to personnel and production output to complete regular maintenance. Xgard Bright MPS™ is tailor-made for Hydrogen detection, with the MPS™ sensor, only one device is needed saving space without compromising on safety. 


Our MPS™ sensor technology has been designed for today’s multi-gas environments, resists contamination and prevents sensor poisoning. Give your teams peace of mind with a purpose-built device in any environment. The MPS technology in our portable gas monitors detects hydrogen and common hydrocarbons automatically in one sensor. Our reliable and dependable Gasman with industry leading sensor technology that your applications demand.

Gasman MPS™ provides a ‘TrueLEL™’reading for all flammable gases in any multi species environment without requiring calibration or scheduled maintenance over its 5-year+ lifecycle, reducing interruptions to your operations and increases up-time. Being poison resistant and withbattery life doubled, operators are more likely to never be without a device. Gasman MPS™ is ATEX Zone 0 approved enabling operators to enter an area in which an explosive gas atmosphere is present continuously or for long periods without fear their Gasman will ignite their environment. 


T4xAs the industry is continuously demanding improvements in safety, reduced environmental impact, and lower cost of ownership; our reliable and dependable portable T4x gas monitor meets those needs with its industry-leading sensor technologies. It is specifically designed to meet the demands of your applications. 

T4x helps operations teams focus on more value adding tasks by reducing the number of sensor replacementsby 75% and increasing sensor reliability.    

Through ensuring compliance across site T4x helps health and safety managers by eliminating the need to ensure each device is calibratedfor the relevant flammable gas as it accurately detects over 15 at once. Being poison resistant and withbattery life doubled, operators are more likely to never be without a device.​ T4x reduces the 5-year total cost of ownership by over 25% and saves 12g of lead per detector which makes it much easier to recycle at the end of its life, and better for the planet​. 

For more on Crowcon, visit or for more on MPS visit

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