A room-temperature SAW methane sensor with Cryptophane-A film

Methane is an important but dangerous industrial gas. Compared with existing methane gas sensors, Surface Acoustic Wave (SAW) sensor exhibits many unique advantages like smaller size, fast response and room temperature operation. Thanks to the good affinity to methane molecules, the Cryptophane-A (CrypA) was chosen as the sensitive interface coated onto the SAW device surface for methane sensing operating at room temperature.

Moreover, a 300MHz two-port SAW resonator with low insertion loss (~3dB) and high quality factor (~2500) were developed, and acted as the feedback element of a differential oscillation structure. To improve the methane sensor performance, the CrypA coating method was optimized, that is, an gas experiment was conducted, in which, CrypA was deposited on the sensing SAW resonators via drop-coating and spin-coating, respectively.

The experimental results indicated that drop-coating method achieved much larger response (~1 kHz) over the spin-coating (~200Hz) because of the larger roughness. Satisfactory sensitivity and detection limit were observed in the gas experiments.

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Applied Nanotech Receives Contract to Develop Methane Sensor

Applied Nanotech Holdings, Inc. announced that it has received a contract from NYSEARCH - Northeast Gas Association (NGA), worth more than $500,000, to fund prototype development of a small, reliable, low-cost methane (natural gas) sensor for residential and industrial applications. The Pipeline and Hazardous Material Safety Administration (PHMSA) of the US Department of Transportation is cofunding this program.

Natural gas is predominantly made up of methane. The methane sensor will be used in detecting natural gas leaks and other safety and analytical tool applications. The sensor will be capable of measuring the methane concentration from 0% to 100% in air at different pressures, different relative humidity levels, and in a wide temperature range. As a safety sensor, the measurement range of primary interest corresponds to 0.25% to approximately 5% gas concentration in air. The sensor technology is designed to be sensitive only to methane, and will not respond to other hydrocarbons, thus reducing the occurrence of false alarms that plague other methane sensor technologies.

This contract follows up on earlier phases of the program funding development of engineering prototypes that demonstrated feasibility in field trials at NGA member companies. This contract will take the engineering sensor prototype to the next stage of design and fabrication of fully functional natural gas sensor commercial prototypes ready for manufacturing, working with strategic partners. The sensor is compatible with a mobile platform.

"We are very encouraged by the progress of this technology towards commercialization," said Dr. Zvi Yaniv, President and Chief Operating Officer of APNT. "This contract recognizes the importance of this technology to natural gas safety applications and demonstrates our progress in commercializing APNT core technologies."

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A portable remote methane sensor using a tunable diode laser

A portable remote methane sensor using a 1.65 µm InGaAsP distributed-feedback laser is developed. It is designed as a man-portable long-path absorption lidar using a topographical target with a range of up to about 10 m.

An operator can search for gas leaks easily by scanning the laser light. High sensitivity is accomplished by means of second-harmonic detection using frequency-modulation spectroscopy. The experimental detection limit (signal-to-noise ratio = 1) with a diffusive target of magnesium oxide (6 m range, normal incidence) is 450 ppb m with a time constant of 100 ms.

Measurements of the reflectance of real targets show that the sensor can distinguish small gas leaks (typically 10 cm3 min -1) within a range of several metres.

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Highly Sensitive, Room Temperature Methane Gas Sensor Based on Lead Sulfide Colloidal Nanocrystals

A solid-state methane gas sensor based on PbS colloidal nanocrystals has been fabricated and tested for the first time. PbS nanoparticles have been synthesized during an all-chemical process and its X-ray diffraction (XRD) pattern has been analyzed to verify the quality and estimate the particle size of produced nano-powder. TEM microscopy and size estimation by XRD analysis both confirm the production of 40-nm PbS nanoparticles. The sensor was fabricated by the drop casting method on interdigitated electrodes and tested at different conditions. 

The best achieved sensitivity was 47.6% for 5% methane concentration at room temperature. A comprehensive discussion on sensing mechanism, temperature dependence, and sensor's benefits is also provided in this paper. 

The sensor has the benefit of room temperature detection and being highly sensitive. Moreover, the sensor's detection range is 1%-5% which is of superior importance in air quality monitoring and safety control systems in industrial environments to prevent suffocation and explosion.

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Automatic Carbon Dioxide-Methane Gas Sensor Based on the Solubility of Gases in Water

Biogas methane content is a relevant variable in anaerobic digestion processing where knowledge of process kinetics or an early indicator of digester failure is needed. The contribution of this work is the development of a novel, simple and low cost automatic carbon dioxide-methane gas sensor based on the solubility of gases in water as the precursor of a sensor for biogas quality monitoring. The device described in this work was used for determining the composition of binary mixtures, such as carbon dioxide-methane, in the range of 0–100%. The design and implementation of a digital signal processor and control system into a low-cost Field Programmable Gate Array (FPGA) platform has permitted the successful application of data acquisition, data distribution and digital data processing, making the construction of a standalone carbon dioxide-methane gas sensor possible.

Low-cost chemical analysis sensors can have a great impact in fields such as environmental preservation and energy efficiency. There is a growing market for this kind of sensor, especially for low-cost and reliable sensors focused on carbon dioxide (CO₂)-methane (CH₄) mixtures in biogas quality monitoring applications. Currently, the most studied method to transform waste into energy is anaerobic digestion, which can convert a variety of wastes, such as agricultural waste from animals and plants and municipal waste, into a full energy product such as biogas. The preferred technology for the analysis of single components in raw biogas, specifically to determine the CH₄ and CO₂ content, is optical sensors, which detect infrared absorption in the characteristic wavelengths for these molecules. In the literature, biogas composition has been measured with gas infrared analyzers, such as those used by Sedlačík and Dvořáčková, who utilized a GASCARD II infrared gas sensor from Edinburgh Instruments; Nordberg et al., who used a Model 6500 visible/near-infrared scanning monochromator from FOSS NIRSystems and Steyer et al. , who used a Siemens Ultramat 22P, which works on the principle of the nondispersive absorption of infrared light. Additionally, semiconductor diode lasers for use in the mid-infrared spectral region based upon lead-salt operating near 7.8 μm have also been used for methane measurements. However, there are two main drawbacks to the sensors outlined above: high cost and difficulty of installation at all biogas production sites. For comparison, the cost of a commercial FTIR spectrophotometer is near $20,000 USD, while the estimated cost of the gas sensor described here is approximately $5,000 USD. The described sensor is also easy to build and operate.

Methods for the acquisition of biogas methane content based in a variety of measurement principles have been reported in the literature. For example, Mandal et al. determined biogas quality using flame temperature as the measurement principle. In this case, the steady-state flame temperature was measured using a system consisting of a thermocouple probe and an analog temperature indicator. In addition, Rego and Mendes  and Rego et al. described a permselective gas sensor for determining the composition of carbon dioxide-methane mixtures in the 0–100% range. The sensor consisted of a permselective membrane, a pressure transducer for measuring the permeate pressure and a needle valve for controlling the permeate outlet to the atmosphere. Furthermore, Rozzi et al. used a thermostatically controlled cell containing 0.1 mol · L⁻¹ sodium bicarbonate in which the pH was monitored by an Orion combination glass electrode and an Orion Model 601A specific ion meter. When the pH reading had stabilized, gas samples were taken using a syringe and analyzed for CO₂ and CH₄ content using gas-solid chromatography on molecular sieves with nitrogen as the carrier gas and a katharometer for the detector.
Carlson and Martisson presented a technique to quantify variations in ultrasound pulse shape caused by interactions between the constituents of a two-component gas mixture as an alternative method to extract information concerning the molar fraction of a gas in a binary mixture. Additionally, Tardy et al. developed a dynamic thermal conductivity sensor for gas detection based on the transient thermal response of a SiC micro-plate slightly heated by a screen-printed Pt resistance. This device was intended for specific application in the determination of the specific gases in a mixture.
Gonzalez et al. used a device that passed the produced biogas through an Erlenmeyer flask filled with a 20% NaOH solution followed by a tube filled with soda lime pellets. The gas then passed through a Mariotte flask system containing water for the quantification of methane production. The displaced water was collected in a plastic container on a pressure sensor (QB 745, DS-Europe) for continuous monitoring of CH₄ production.
A Field Programmable Gate Array (FPGA) is an array of basic logic blocks where the user can define its interconnectivity, making it programmable in a fully open architecture. Therefore, an FPGA provides the advantages of a general-purpose processor and a specialized circuit that can be reconfigured as many times as necessary until the required functionality is achieved. The speed and size of the FPGA are comparable with the Application Specific Integrated Circuit (ASIC), but the FPGA is more versatile and its design cycle is shorter because of its reconfigurability. FPGA applications go beyond the simple implementation of digital logic; they can be used for the implementation of specific architectures for speeding up some algorithms. A specific structure for an algorithm implemented into an FPGA could have 10–100 times higher performance than its implementation on a Digital Signal Processor (DSP) or microprocessor.
Due to the sequential processing data flow on commercially available DSPs and microprocessors, the increase in sampling rate, mathematical processing, or versatility can impose severe restrictions on processor performance. Therefore, other alternatives for signal processing must be considered to achieve real-time data acquisition and data pre-processing. Moreover, FPGA devices have been gaining market share in system on chip (SOC) applications because they can integrate processing units defined by the user and related peripheral logic in the hardware, combining open architectures that do not depend on the manufacturer or specific platforms. However, DSPs and microprocessors have a fixed sequential construction for computation, which can easily be overloaded when the processing time between samples is significantly reduced, as in high-speed control, while FPGAs have a natural parallel architecture for high-speed computation. Along with the advantages previously cited, FPGA development is performed under Hardware Description Language (HDL), making the design portable and platform independent, which is not the case for commercially available DSPs or microprocessors.

In this paper, the development of a low-cost automatic carbon dioxide-methane gas sensor based on the principle of the solubility of gaseous species in water is reported. The novelty of this work is two-fold. First, a physical principle, never used before, is applied for binary mixture quantification, drastically reducing the cost and complexity of the equipment and facilitating on-line monitoring. Second, the hardware implemented in the FPGA has the capacity for data acquisition, data distribution, data processing, data communication and control, adding functionality and autonomy to the automatic carbon dioxide-methane gas sensor and allowing it to be deployed in the field.

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Learn About The Technical Aspects Of Methane Sensors

In today’s world, the oil and gas industry is focused on keeping employees as safe as possible. To make this happen, many companies have concentrated on purchasing and installing methane sensors at manufacturing facilities, processing plants, offshore rigs, and pipelines. Considered to be the most important part of a fixed gas detection system, a methane sensor can literally mean the difference between life and death. But to make sure a plant or offshore rig has the best possible methane sensor, there are many technical aspects they should know more about.

Gas Detection
The main purpose of methane sensors is to monitor and detect levels of methane gas in the air, making sure that personnel are alerted to levels that approach dangerous conditions. Measuring levels of gas in relation to the Lower Explosive Limit, sensors can also measure methane by its volume in the air, ensuring there is little chance that potentially dangerous levels will not be detected.

Catalytic Beads
Used before infrared sensors, catalytic bead sensors have nevertheless proven to be very effective over the years. Although being prone to contamination from lead, sulfur, silicone, and other compounds, catalytic bead sensors have provided good results. However, these sensors do require calibration on a regular basis in order to keep them in excellent working order. As a result, even though these sensors are relatively inexpensive, they do need to be replaced regularly. Because of this, the cost associated with replacing them must be taken into consideration.
Infrared Sensors
Now looked upon as the leading sensor technology when it comes to methane detection, infrared sensors have a distinct advantage in that they do not require oxygen to operate. Due to this, these sensors can be used in many more work environments that previous types of sensors. Whether it’s a natural gas pipeline, offshore rig, or chemical processing plant, infrared sensors can be easily adapted to a variety of work environments.
Individual Preferences
While both catalytic bead and infrared sensors have their advantages, most companies ultimately rely on individual preferences depending upon their needs. One of the major reasons for this is that catalytic bead converters can sometimes be used in environments where other combustible gases may be present. In these potentially dangerous situations, the catalytic bead sensors may be able to pick up traces of these gases, where infrared sensors may not.
Work Conditions
When it comes to methane sensors, several factors in the work environment can play a role in the effectiveness of these sensors. The most common factors involve workplace temperatures and humidity, which can greatly influence the effectiveness of the sensors. In most situations, work environments that have humidity levels above 70 percent present the greatest challenges. In these situations, the wet air can sometimes play havoc with getting proper results, leading more companies to use infrared sensors due to their reliability and accuracy. Along with this, areas prone to being filled with dust or dirt also use these sensors to gain accurate results for workers in those areas.

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Rapid hydrogen and methane sensors for wireless leak detection

Under NASA STTR NNK07EA39C, ASR&D developed passive surface acoustic wave (SAW) based hydrogen sensors that utilize Pd nanocluster films on self-assembled siloxane monolayers to provide rapid, reversible room temperature responses to hydrogen exposure. Under NASA SBIR NNX09CE49P ASR&D demonstrated wireless interrogation of SAW RFID sensor-tags. In this project, we propose to combine the results of these two technology development programs to produce wireless, uniquely identifiable SAW-based hydrogen sensors, and to evaluate the sensor response time to low levels of hydrogen exposure (down to 1 ppm). ASR&D will also implement a SAW-based in-situ Pd deposition monitor for enhanced film reproducibility. ASR&D's previous hydrogen work was based on Argonne National Labs work with similar films that demonstrated hydrogen sensing from 25 ppm to over 2% hydrogen, with response times of milliseconds, complete reversibility, and no baseline drift at room temperature. ASR&D demonstrated the ability to measure changes in such films using a SAW sensor, however our ability to test at low hydrogen concentrations and at rates exceeding 1 sample/sec were limited by our experimental test equipment. In the proposed effort, we will utilize an Environics gas dilution system to generate calibrated gas concentrations (for hydrogen and methane) down to 1 ppm, and we will utilize the electronic interrogation system being developed for our RFID work to measure the sensors. This system is capable of measuring sensor responses with a good S/N in 1 msec (or less), overcoming the prior limitations of our testbench equipment. In addition to the hydrogen sensor work, working with Temple University, we propose to evaluate the technical feasibility of producing SAW-based methane sensors using a similar SAW sensor device, but incorporating methane selective supramolecular cryptophane films. Hydrogen sensors will be TRL4 at completion of the proposed effort, and methane sensors will be TRL 3.
POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
The primary NASA application for the proposed sensors would be in a wireless multisensor system for real-time leak detection in areas surrounding hydrogen and methane storage. The potential ability of these sensors to respond in msec with quantitative measurements of hydrogen and methane at ppm concentration levels, combined with the demonstrated ability to uniquely identify each sensor and read the sensors wirelessly, should enable implementation of a wireless distributed real-time leak monitoring system. The ability of the sensors to operate without batteries will allow deployment on long-term missions and minimize maintenance requirements.
POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
There are two potential commercial applications for the proposed rapid, high sensitivity hydrogen sensors. The first is quantitative determination of hydrogen concentration in human breath, used as a diagnostic tool for health conditions such as lactose intolerance. Bacteria in the human digestive system produce low levels of hydrogen in exhaled breath (typically 7±5ppm), and analysis of the hydrogen concentration is part of the diagnostic process for several conditions. Tests involve having the patient eat or drink something that will cause the bacteria to produce increased levels of hydrogen, and then monitoring breath for the resulting gas concentration. The second application relates to hydrogen generation, delivery, and storage leak detection and monitoring. The high sensitivity, fast response times, reversibility, wide range of hydrogen concentration sensed, low cost, and small size would make the proposed sensors applicable to these emerging market segments.
NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.

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A methane gas sensor based on oxidizing bacteria

A bacterial sensor system based on Methylomonas flagellata AJ 3670 is described for methane determinations. The system consists of a bacterial, reactor, a reference reactor and two oxygen sensors.

The current decreases with time until a steady state is reached within 30 s at 30°C; the maximum current difference is obtained at 30°C and pH 7.2. The response time for the determination of methane is less than 1 min.

A linear relationship is obtained between the current difference and the methane concentration below 6.6 mM; the lower limit of determination is 5 μM, and the current decrease is reproducible within 5%. The current output of the methane gas sensor is almost stable for more than 10 days and 250 assays.

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Turkish coal mine disaster could have been avoided with methane sensors

A recent incident of methane poisoning in a mine in Turkey caused the deaths of mine workers, highlighting once again the dangers of underground coal mining.If they have used the methane sensors, the disaster can be avoided finally.
Considered one of the most dangerous work environments in the world, underground mines expose workers to extreme temperatures and confined spaces, both factors taking a heavy toll on any miner.
However, methane gas is another risk present down the shaft of a mine. A naturally occurring substance, methane gas is released as part of the coal mining process. But the gas is dangerous and potentially lethal without the proper detection and protective equipment.
In the Turkish incident, 18 workers were trapped in the coal mine near Ermenek, in the Turkish province of Karaman last October. Mine rescue teams were unable to enter the entry point for a number of days due to flooding. When the water subsided, emergency services could get to some of the men.
After 10 days in the flooded underground conditions, two miners were found dead. Mine rescue teams pulled out another eight after an additional 12 days. Though the deaths were initially attributed to drowning due to the flooded shaft, the hospital autopsy pointed to methane gas as the killer.
There are also grave fears for the eight miners who are still trapped down the mine. Due to increasing levels of carbon dioxide and a lack of oxygen, it has been impossible to reach them. The arrival of winter in the area has also hampered rescue attempts due to snow.
Underground mines typically install methane detectors and refuge chambers to combat methane gas levels. People can survive for up to 30 days inside a refuge chamber while waiting for emergency services to arrive. Instead the miners were found huddled close to each other against a section of the mine as they tried to escape the fumes.
Mining and other professions in similarly dangerous environments require businesses to be up-to-speed on workplace safety and also install the best gas detector equipment available.
In addition to refuge chambers, businesses could introduce devices such as the testo 316-1 methane gas detectors, which are capable of locating the smallest leaks of methane, and can be hooked on to the workers’ belt. An optional TopSafe case protects the device from dirt and impacts belowground.

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NASA’s Tiny Methane Gas Sensor Designed For Mars Will Go to Work on Earth

A tiny methane gas sensor has been developed by NASA’s Jet Propulsion Laboratory, equipped with a laser spectrometer, originally designed for gas testing on Mars.
However, the sensor is small enough that it can easily be fitted to a drone, where it could then be used to sniff out methane leaks around the world.

Capable of sniffing out a few parts per billion, NASA’s tiny methane gas sensor is about to be flying over gas pipelines on Earth by way of a drone, where it will help detect methane leaks for the natural gas industry.

If it never makes it to Mars, at least NASA’s mini methane gas sensor will find plenty of work at home.

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Google equips Street View cars with methane sensors to detect gas leaks

Street View cars are primarily used for collecting panoramic imagery of major cities and tourist attractions around the world, but that's not the only task they're mandated with. Google has outfitted a few Street View cars with methane sensors that enable the cars to check for natural gas leaks in the surrounding areas.

Google Earth Outreach teamed up with the Environmental Defense Fund back in July to launch a test pilot of three Street View cars outfitted with methane detectors, and sent the vehicles to Boston, Staten Island, and Indianapolis. The results of the month long survey are in, and as you can discern from the images below, they highlight the fact that older gas lines, like the ones in Boston, are more prone to leakage. While none of the gas leaks pose any immediate threat, the EDF and Google are working with regulators in monitoring and prioritizing repairs.

Google will be launching more methane sniffing Street View vehicles in other cities over the coming months. What do you guys think of the initiative? What other sensors would you like to see on Street View cars?

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Auto-Calibration Technology of Mine Methane Sensor and its Research Progress

Based on a brief introduction of the key technology of mine methane sensor,this paper mainly deals with the drift reduction of gas sensor,including the zero-adjustment,sensitivity correction and nonlinear compensation of methane sensor and their research progress.Several new techniques were introduced,such as genetic algorithm,wavelet decomposition and the implementation method using DSP.

Especially the sensor′s nonlinear auto-calibration method using neural network was described.The RBF neural network was used as an inverse model that was trained to perform the mapping among the sensor′s readings and the actually sensed properties.

With its converging speed,classification capability and approach capability,the RBF neural network has become a hot research area.

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Optic Fiber Methane Gas Sensor Based on Tunable Diode Laser Absorption Spectroscopy

 Tunable diode laser absorption spectroscopy (TDLAS) is a widely used technique in measuring the concentration of trace gas due to its high sensitivity, high selectivity, and fast time response.

The fluctuations of temperature in the gas cell can cause the characteristics of the absorption spectra to change in the TDLAS methane sensing system. The three absorption lines in the R(3) transitions of 2v3 band of methane at 1653.72 nm have been studied, and the influence of the temperature fluctuations on the spectral absorption coefficient and the amplitude of second harmonic is analyzed.

A simple piece of equipment with temperature acquisition devices is developed for measuring methane gas concentration, temperature signals are obtained for eliminating the impact of temperature fluctuations.

Using calibration coefficient, the amplitude of second harmonic is transformed into standard signal at reference temperature in order to restrain the influence of temperature fluctuations. The results show that this optic fiber methane gas sensor using tunable diode laser absorption spectroscopy can restrains the influence of temperature fluctuations and improves detection accuracy effectively.

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Methane Sensor for Mars

Methane Sensor for Mars (MSM), on-board Mars Orbiter Mission is a differential radiometer based on Fabry–Perot Etalon (FPE) filters which measures column density of methane in the Martian atmosphere.

It is the first FPE sensor ever flown to space. Spectral, spatial and radiometric performances of the sensor were characterized thoroughly during the pre-launch calibration. Geophysical calibration of the sensor was carried out using the data acquired over Sahara desert during Earth Parking Orbit phase.

Retrieval algorithm for MSM, which is based on the linearization of radiative transfer equations, gets simultaneous solutions for CH4 and CO2 concentrations in the Martian atmosphere.

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New methane sensor installed in the Arctic Ocean

Researcher Kasia Zamelczyk and PhD Candidate Pär Jansson from CAGE participated on the second leg of the RV Polarstern-expedition to the deep- sea observatory Hausgarten. The observatory is a network of 21 stations at water depths ranging between 250 m and 5500 m in the Fram Strait. RV Polarstern has revisited the observatory annually for the past 17 years, collecting long-term ecological data sampled by different instruments throughout the network.

“Our main purpose was to install a methane sensor and a CTD instrument (used to measure the conductivity, temperature, and physical properties of the ocean) on the deep lander platform in central Hausgarten says Zamelczyk.

Scientists expect to obtain a time series record of bottom water properties such as temperature, salinity and pressure as well as methane concentrations. The instruments were deployed at a water depth of 2500 meters, where no direct methane emission is expected. The data acquired at this location will mainly serve as a reference to compare with other sensors placed in active emission sites. Methane is a potent greenhouse gas that is naturally seeping from the ocean floor.

This work was conducted within the FixO3 project, which seeks to integrate European open ocean fixed-point observatories.

Additional sampling offshore Svalbard
In addition Zamelczyk and Jansson collected CTD profiles and water samples for methane concentration measurements at active methane seep locations close to Prins Karls Forland, Svalbard.

“Water sampling will result in methane concentration profiles for 12 different depths. These profiles will help us to estimate the magnitude of methane emissions and how high the methane can reach in the water column. In total 48 bottles were collected in an area where we have seen a lot of methane seeping from the seafloor” says Jansson.

Also, zooplankton net and surface sediment samples were collected at the same locations. These samples will be used to study the impact of methane release from the ocean floor on shells of planktonic (living in the water column) and benthic foraminifera (living at the ocean floor).

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Compensation for surface contamination in a D-fiber evanescent wave methane sensor

The effects of surface contamination on the performance of a D-fiber evanescent wave methane sensor are discussed. Contamination on the flat surface of the D-fiber will modify both the scale factor of the methane detection system and the birefringence of the D-fiber.

The birefringence variation can be monitored and used to compensate for the scale factor variation, through one of the two compensation models which will be described in the text. The models are found to be fairly accurate, and for the D-fiber used in our experimental tests, the maximum relative error for scale factor correction is about ±5%, for both models.

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Advantages of Methane Sensor

As the production of natural gas has increased, many oil and gas companies have made it a priority to turn their attention to this area of the industry. Because of this, making sure gases such as methane can be closely monitored to ensure no leaks occur is vital to employee safety. To do this in the safest way possible, more and more companies are choosing to invest in methane sensors. A must-have at production sites and refineries, a methane sensor can provide numerous benefits to prevent catastrophic accidents from happening.

Production Efficiency
Along with making natural gas production areas safer by monitoring for possible leaks, methane sensors are also key components in production efficiency. When leaks occur while gas is being extracted, a company’s profits can decrease substantially. To keep this from happening, companies now install methane sensors at various spots to keep careful track of gas levels. By having these sensors available, companies save money in various ways. The sensors themselves are low-cost and low-maintenance, while also allowing for real-time reporting and tracking to pinpoint leaks.

Fire Safety Protection
Due to the high flammability of methane, installing methane sensors in key locations can provide a strong level of fire safety protection for employees and others nearby. When an unknown leak is present, time is of the essence. If not detected quickly, the result can be an explosion of extreme proportions.

Gas Extraction
Closely related to production efficiency, gas extraction can be made much more efficient with the installation of methane sensors. When well sites leak methane, a large percentage of machine operation and manpower is wasted. By having a methane sensor nearby, production levels can stay high while labor costs can also remain steady.

Greenhouse Gases
Because most people working in the natural gas industry want the production process to be environmentally friendly, it’s imperative that methane sensors be used to discover any leaks that are occurring. Otherwise, the methane will be leaked into the atmosphere and result in additional greenhouse gases that lead to global warming. By having methane sensors on-site, this situation can be greatly reduced or eliminated.

Remote Data Transmission
Because many natural gas well sites are located in remote areas that sometimes produce harsh working conditions, the sensors being used must be able to withstand all of the potential weather elements and other obstacles. Due to this, the sensors must have the capability to transmit data instantly to locations many miles away. Therefore, the sensors used must be able to download information to smartphones, laptop computers, tablets, or other mobile devices as needed. Both real-time data as well as historical data can be transmitted, helping management personnel analyze current data as well as trends in order to help them make any configuration or calibration changes.

Methane sensors, while being very cost-efficient and reliable, can also play a pivotal role in maintaining workplace safety. By taking these and other steps, a company can not only protect people and equipment, but also maintain its profits and protect the environment.

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NASA’s Methane Sensing Drone Was Successfully Tested

Generally, we expect NASA to design technology related to space travel. And that is exactly what they do. But occasionally, because of the intense work and testing that goes into designing a NASA piece of technology, it tends to be often implemented in other technological fields. Otherwise, a lot of good, efficient work would go to waste.
So, other important pieces of technology are often developed using the same principles, if not some of the same hardware that NASA themselves use. And the Agency, in desperate need of funding, is often involved in the production of those as well. Developed by the Jet Propulsion Laboratory in Pasadena, California, NASA’s methane sensing drone was successfully tested.
Called the sUAS, or the Vertical Take-off and Landing small unmanned aerial system, the drone carrying the methane sensor was especially picked for the increased maneuverability and access offered to the sensor. The best feature of the sUAS is its very high vertical access which allows the sensor to get as close as it needs to pretty much any possible source of gas.
But the sensor is the real impressive part regarding the whole rig. Similar to the one developed by JPL to be used on Mars, the sensor enables the detection of methane gas with a far superior sensitivity than any other previous device designed for this particular purpose. Among its wide range of applications, it’s very useful in detecting small methane leaks on industrial pipelines.
Funded by the Pipeline Research Council International, the device has been tested and underwent various demonstrations since 2014. The most recent series of testing in regards to NASA’s Open Path Laser Spectrometer took place in Central California, at the Merced Vernal Pools and Grassland Reserve.
According to Lance Christensen, JPL principal investigator of NASA’s Open Path Laser Spectrometer,
These tests mark the latest chapter in the development of what we believe will eventually be a universal methane monitoring system for detecting fugitive natural-gas emissions and contributing to studies of climate change.
The test flights for the drone were conducted in February by researchers from the MESA (Mechatronics, Embedded Systems and Automation) Lab in Merced. They mostly consisted of flying the drone at various distances from methane source in order to more accurately determine its accuracy, mobility, and resistance.
Further attempts at perfecting the entire rig will consist of fixing the sensor to a fixed wing unmanned aerial system, which would allow it to fly for longer times and distances, making it ideal for detecting possible leaks in pipelines situates in remote, rural areas.

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Tiny methane sensor attached on a drone successfully spots methane leaks more accurately than modern instruments

Researchers have registered success in a field test in which a small methane sensor was attached to a small drone. Main aim was of the experiment was to test the ability of sensor to find out methane leaks more accurately than modern instruments, said NASA.

The methane gassensor has been developed as a part of project to improve safety in the energy pipeline industry. The sensor developed by NASA’s Jet Propulsion Laboratory and University of California, Merced’s Mechatronics, Embedded System and Automation Lab allows detection of methane with a much greater level of sensitivity than the instruments available in the industry.

The field tests were carried out in central California at the Merced Vernal Pools and Grassland Reserve. The test of NASA's Open Path Laser Spectrometer (OPLS) sensor is considered to be the latest effort in a methane testing and demonstration program carried out on different programs since 2014.

The experts said that the ability of the OPLS sensor to detect methane in parts per billion in terms of volume could help the pipeline industry to have better accuracy about small methane leaks. The tests were carried out in late February in which they have flown a small unmanned aerial system equipped with the OPLS sensor at different distances from methane-emitting gas sources.

The tests were carried out in a controlled setting to test the accuracy and robustness of the system. The sensor was tested on a Vertical Take-off and Landing small unmanned aerial system (sUAS). The advanced capabilities provided by sUASs could extend the use of methane-inspection systems for detecting and locating methane gas sources.

This year, more flight tests will be carried and they will feature a fixed-wing UAS that can fly longer and farther. The latest round of tests will push the team’s goal to develop sUASs to improve traditional inspection methods for natural-gas pipeline networks.

ISweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrialproducts

Nonlinear Correction of Methane Sensor Based on Functional Link Neural Network

The nonlinear relation between methane concentration and the output voltage of the sensor is indicated by analysis of detection principle of catalytic methane sensor.

This paper proposes a nonlinear correction model based on functional link neural network (FLNN) with the output voltage of methane sensor as input and the methane concentration as output to eliminate the nonlinear errors in methane detection. By adding some high-order terms, the model applies the single-layer network to realize the network supervised learning.

The approach has advantages of nonlinear approach ability and independent on accurate mathematical model, it can improve network learning speed and simplify the network structure.

The experimental result shows that the maximum relative error of simulation curves is reduced to 0.86%, which is much smaller than that of piecewise linear fitting curve with 3.09%. The detection accuracy of methane sensor is improved.

ISweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrialproducts