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Gas detection is a crucial safety measure in many industries, including chemical manufacturing, environmental monitoring, and oil and gas. Gas detection systems are implemented to accurately and quickly identify gas leaks, which is critical as many gas hazards can be hard to detect due to invisibility or lack of scent. One highly reliable method of identifying gas hazards is infrared gas detection, which utilizes infrared light to identify gases based on how they absorb specific wavelengths of light. In this blog post, we will explore how infrared gas detection works and the benefits of this method.

Infrared Gas Detection

Infrared gas detection systems are used in various commercial, industrial, and scientific applications as they offer long-term stability, high sensitivity, and accurate gas detection based on how gas molecules absorb infrared radiation (IR) at specific wavelengths.1

The components of an infrared gas detection system include a chamber with an emitter (such as an IR lamp) on one side and, on the other side, an optical filter and thermopile detector. Gases enter the chamber, and molecules within the gas will absorb some of the IR energy from the emitter. This process reduces the amount of energy or response at that specific wavelength, and based on the Beer-Lambert Law, the gas absorption is measured and analyzed to identify the concentration of gas present. If no gas is present, the thermopile will measure the energy received from the IR source and produce a proportional electrical signal.

Advantages of Infrared Gas Detection

There are numerous benefits to using infrared gas detectors, with two key points being their ability to detect gases that are transparent to visible light or those with low concentrations. They are also used to detect a wide range of gases at different temperatures, pressures, and visibilities. Other key benefits include the following:

• A highly reliable and accurate method of gas detection
• Easy to-use systems
• Fast response times
• High sensitivity and specificity
• Low maintenance due to factory calibration
• Minimal interference from environmental factors
• Minimizes risk of contamination or poisoning

Dexter Research Center

Dexter Research Center was founded in 1977 by Robert Toth, Sr., Ph.D. to bring low-cost, high-performance infrared sensing to customers around the world. Our products offer superior sensitivity, enhanced signal-to-noise ratios, and meet MIL-Spec reliability and durability testing standards.

We provide our customers with over 1,000 thermopile configurations and a range of encapsulating gas options to offer superior sensing needs for a range of applications and industries. Our thermopile detectors are used in systems for gas analysis, gas detection, and flame sensing, and we continue to develop these products to meet high-market demands.

Contact a member of Dexter Research Center today to learn more about infrared gas detection.

References and Further Reading

https://www.azosensors.com/article.aspx?ArticleID=675
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8838934/

Thermopile detectors are used to measure the temperature of objects at a distance by converting infrared (IR) radiation into an electrical signal. This single main functionality serves a raft of functions across industry and science, enabling high-precision non-contact temperature measurements of a near-limitless range of substrates. High-sensitivity thermopile sensors also compare favourably with other types of temperature sensor modules in terms of durability and stability, making them ideal for intensive and routine applications alike.

This article will explore the working principle of thermopile detectors and the various applications they serve in multiple industries.

What is the Working Principle of a Thermopile Detector?

Understanding thermopile detectors requires a cursory understanding of thermocouple technology. Thermocouples–the most prevalent type of electrical temperature-sensing element–comprise two dissimilar metal wires bonded to form a “hot junction” and a “cold junction”. When the joint is heated or cooled, it generates a weak voltage (V), also known as the Seebeck voltage, which corresponds to the change in temperature. There is also a proportionality factor to consider, but for the purposes of this article, it is enough to know that the voltage generated is directly proportional to the temperature difference between the hot and cold junctions.

Thermopile detectors comprise an array of thermocouples connected in a series. The underlying idea is to multiply the effect of each individual element. They can be considered a group of miniature thermocouple junctions–similarly divided into hot and cold junctions–which are composed of alternating n-type and p-type materials, referred to as “arms”.

The arm materials vary with different thermopile types. Thin film systems, for example, tend to comprise arms of antimony and bismuth, while silicon thermopiles comprise alternating n-type and p-type Poly-Silicon or n-type and Gold or Aluminum. The cold junctions are generally connected to the detector package and around the perimeter, while the hot junctions–which define the active area–are located in the center and coated with an energy absorber. These hot junctions are suspended on a thin membrane to thermally isolate them from the rest of the package. So, how does the array work?

As mentioned, the multiple thermocouples in a thermopile detector are connected in series, which means that the voltage difference generated by each one is added together to produce a total voltage output. This total voltage output is proportional to the temperature of the object being measured. Since the Seebeck effect is a relatively weak signal, thermopile detectors are equipped with voltage amplifiers to ensure the signal can be read by a meter or data acquisition (DAQ) system. A calibration factor or transfer function is then used to convert the signal into a legible temperature measurement.

Applications of Thermopile Detectors

Thermopile detectors have various applications in various industries due to their accuracy, stability, and durability. Some of the critical applications of thermopile detectors are listed below:

• Energy: Thermopile detectors are used for temperature control in boilers and heating systems. They are also used in solar panels for monitoring the temperature of the panels, ensuring that they operate at the optimal temperature for maximum efficiency.
• Automotive: Thermopile detectors are used for temperature sensing in engines, exhaust systems, and catalytic converters. They are also used for temperature monitoring in battery packs in electric vehicles.
• Aerospace: Thermopile detectors are used for temperature monitoring in spacecraft and satellites. They are also used in aircraft engines for temperature sensing and control.
• Medical: Thermopile detectors are used for temperature measurement in medical equipment, such as infrared thermometers. They are also used in non-invasive temperature monitoring in the human body, such as in fever detection.
• Industrial: Thermopile detectors are used for temperature control and monitoring in various industrial processes, including drying, baking, and heat treating. They are also used in industrial ovens and furnaces for temperature control.

Looking for Thermopile Detectors?

At Dexter Research Center, we lead the way in delivering infrared sensing solutions for various detection applications. For more information about thermopile detectors, refer to the technical papers section of our M5 Thin Film-based thermopile detector product page for a full Introduction to Thermopile Detectors. Should you have any further questions or require assistance, our knowledgeable team is here to help.

A nondispersive infrared (NDIR) sensor is often used as a gas sensor to detect and measure gases in the atmosphere and their concentrations. NDIR sensors work on the principle of molecules absorbing infrared light and specific wavelengths, and air samples are collected in a tube and analyzed under a light source.

NDIR sensors are highly accurate and sensitive devices used in a wide range of applications where monitoring gases and their concentration is crucial. This includes industrial safety, environmental monitoring, and medical applications. In this blog post, we provide an overview of NDIR sensors and discuss their benefits and applications.

NDIR Sensors Working Principle

Some of the most common gases measured with NDIR sensors include carbon dioxide, carbon monoxide, methane, and sulphur dioxide. These gases can be lethal or explosive in high concentrations, so monitoring them is critical in many applications and environments. Gas sensors, such as NDIRs, require a sample chamber, an infrared detector, and an infrared light source.

The sample chamber is placed between the light source and the detector and contains the gas sample that needs to be analyzed. The light source emits an infrared light through the sample chamber and the detector reads how much light passes through. Gas molecules react with infrared radiation and the ratio of radiation energy to incident energy is depends on the gas concentration. The gas sensors measure the gas concentration by monitoring the decrease in transmitted infrared light.

Applications of NDIR Sensors

NDIR sensors can be used in almost every industry for a wide range of monitoring applications. They can be used in breathalyzers to measure blood alcohol levels, identify refrigerent leaks and monitor toxic gases in dangerous environments. In this section, we look at the environmental and industrial and medical applications of NDIR sensors.1

Environmental Monitoring

Monitoring gases is required in many environmental situations, such as monitoring emissions from industrial processes, measuring indoor air quality, and gas concentrations in ambient air. They are ideal because of their high sensitivity and accuracy, but can be impacted by humidity and temperatures, which may require corrective action.

Industrial Applications

In industrial settings, NDIR sensors play a crucial role in keeping personnel and environments safe from toxic or explosive gase as they are highly sensitive to target gases. For environments such as manufacturing plants, they are a cost-effective and reliable solution to ensure worker safety.

Medical Applications

Hospitals also use infrared sensors to monitor gas concentration levels in anesthsia machines to ensure patients are safe during operations.

Advantages of NDIR Sensors

There are a number of advantages to using NDIR sensors in gas monitoring applications. They are low maintenance solutions that offer long-life performance. Other advantages include the following:

• Cost-efficient
• High accuracy and sensitivity
• High selectivity to target gases
• Monitor a range of gases

Although NDIR sensors require a higher upfront cost, their advantages contribute to a lower life-time cost as they offer accurate and reliable gas monitoring over a long period of time. As technology advances, NDIR sensors will be developed further for more advanced monitoring applications.

Dexter Research Center

Dexter Research Center offers a wide selection of infrared gas and temperature detectors that provide a reliable, stable performance for longer. Our products have been used in environmental and industrial monitoring applications, hospital anesthetic monitoring and NASA space missions, and we continue to develop high-quality, reliable devices for clients around the world.

To learn more about NDIR sensors and their applications, contact a member of Dexter today!

References

azosensors.com/article.aspx?ArticleID=675

Miniature amplifiers are crucial components in electronics because they are compact, lightweight, and can be easily integrated into various systems across a range of industries. Mini or micro amps, as they are also known, are used when power options are limited, and space efficiency is vital for the application. Amplifiers are used in scientific research and development applications to support fast startup times, minimal noise, and reduced buffering in scientific instruments and systems.

An Overview of Miniature Amplifiers

Miniature amplifiers play an important role as they help to enhance small or weak input signals. Amplifiers work by converting an input signal into a large format to increase the current, power, or voltage of a signal, which is a crucial process in electronic circuits. Amplifiers rely on power from an existing electrical source, which can be used in various applications such as medical devices, personal and commercial audio equipment, and scientific instruments.

Applications of Miniature Amplifiers

Many electrical applications benefit from amplifiers, especially miniature amplifiers for smaller or more intrinsic systems. Miniature amplifiers are commonly used in data acquisition systems and medical devices, image and signal processing equipment, spectroscopy and audio/video processing equipment, and electrophysiology research to amplify signals and speed up processing times.

Other key applications of miniature amplifiers include the following:

• Multiplexing of a number of thermopiles
• Thermopiles are non-contact sensors used to measure temperature and specific gases. However, they have a high series impediment that requires identifying gas or temperature across a wide range of parameters. This application requires amplifiers with minimal to no noise and the capability to enhance low signals.
• Gas analysis

Amplifiers are used in gas analysis to enhance the signals transmitted through the equipment. Miniature amplifiers reduce noise and improve signals, which leads to more precise gas analysis and higher repeatability of results.

Non-Contact Temperature Measurement

Non-contact temperature measurement is a key application for miniature amplifiers in the sensing solutions industry. These sensors detect the infrared radiation emitted by an object, which is directly proportional to its temperature. However, the output can be extremely weak. Miniature amplifiers enhance the weak input signals received by the sensor, increasing the voltage and current of the signal for a more accurate temperature measurement. This is particularly important in applications where temperature measurement accuracy is critical, such as in medical devices or scientific research.

Dexter Research Center, Inc. and Miniature Amplifiers

Dexter Research Center, Inc. was founded by the leading thin-film and materials expert Robert Toth, Sr., to provide world-class infrared sensing and detect-and-manage solutions for companies worldwide. We provide our clients with a wide range of non-contact temperature sensors and thermopile thin-film and silicon-based products, in addition to ever-evolving thermopile detectors.

We currently offer a Miniature Amplifier PCB, available in three amplifier gains (300, 500, and 1,000) for a range of thermopile applications. The PCB comes with a cable, connector, and 1.25V voltage reference with the option of adding a temperature sensor. The amplifier has an extremely low offset, drift, and bias current for significantly reduced digital switching noise. The PCB was designed to support fast startup times in research and development instruments.

For more information on how miniature amplifiers support a range of applications, please get in touch with a member of Dexter Research today.