{"id":623430,"date":"2026-11-11T13:04:29","date_gmt":"2026-11-11T13:04:29","guid":{"rendered":"https:\/\/www.olympiajournal.com\/news\/story\/623430\/technical-standards-are-writing-quantitative-retrieval-into-requirements-how-gas-imaging-is-evolving-from-a-tool-into-a-metrology-instrumen.html"},"modified":"2026-11-11T13:04:29","modified_gmt":"2026-11-11T13:04:29","slug":"technical-standards-are-writing-quantitative-retrieval-into-requirements-how-gas-imaging-is-evolving-from-a-tool-into-a-metrology-instrumen","status":"publish","type":"post","link":"https:\/\/www.olympiajournal.com\/news\/story\/623430\/technical-standards-are-writing-quantitative-retrieval-into-requirements-how-gas-imaging-is-evolving-from-a-tool-into-a-metrology-instrumen.html","title":{"rendered":"Technical Standards Are Writing Quantitative Retrieval into Requirements: How Gas Imaging Is Evolving from a Tool into a Metrology Instrument"},"content":{"rendered":"

Hangzhou City, Zhejiang Province, China – November 11, 2026 –<\/strong> Technical Standards Are Writing Quantitative Retrieval into Requirements: How Gas Imaging Is Evolving from a Tool into a Metrology Instrument<\/p>\n

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Gas leak monitoring has been stuck in an awkward position for the past few years: it can capture images of gas clouds, but the concentration in those images cannot be clearly stated. For the same leak point, switching to another device may produce a completely different color intensity. Move a little farther away, and the plume that was visible fades. When customers compare demo videos from two manufacturers, the only thing they can compare is “which one looks more obvious.”<\/p>\n

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This situation is coming to an end. GB\/T 48024-2026, Technical Specification for Spectral Video Measurement and Control Early Warning Systems for Hazardous Gases<\/em>, was published on August 28, 2026, and will take effect on March 1, 2027. Its current status is “pending implementation.” It is one of a batch of recommended national standards published under National Standard Announcement No. 38 of 2026.<\/p>\n

1. A Standard That Defines the Performance Boundaries of a System<\/p>\n

The standard is administered by the National Technical Committee for Industrial Process Measurement, Control and Automation Standardization, executed by its Analytical Instruments Subcommittee, and supervised by the China Machinery Industry Federation. The standard category is product, with China Standard Classification No. N53 and International Classification for Standards No. 71.040.10.<\/p>\n

In terms of specific metrics, it covers the number of spectral video channels, spatial pixel specifications, video frame rate, response delay, and detection limit. In terms of functions, it covers intelligent identification, quantitative retrieval, automatic warning, and alarm linkage.<\/p>\n

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Taken together, these items show that it governs not a single component but how an entire system is evaluated. Channel count and pixel specifications determine spatial resolution capability. Frame rate and response delay determine whether transient leaks can be captured. Detection limit determines the smallest detectable magnitude. Each of these three capability groups corresponds to a type of use scenario; if any one is missing, the system is ineffective in that scenario.<\/p>\n

More notably, “quantitative retrieval” has been written into the functional requirements. This means that after recording for evidence, the system must also provide a quantity—moving from an auxiliary troubleshooting tool to a data source that can be incorporated into safety management systems. Once this step is crossed, spectral video is no longer “a camera that sees more than a point probe” but a monitoring device with metrological attributes.<\/p>\n

2. The Prerequisite for Seeing Gas Is a Radiance Difference<\/p>\n

To explain this technology clearly, one must first return to its physical chain. The main C–H stretching absorption bands of light hydrocarbons such as methane are concentrated in the mid-wave infrared 3–5 micrometer range, with methane’s own main band falling at 3.2–3.4 micrometers. The existence of these absorption bands is the first prerequisite for gas to be “seen.”<\/p>\n

But this range cannot be generalized. For heavier hydrocarbons such as ethane and propane, the main C–H stretching band still falls at 3.3–3.5 micrometers, without obvious red shift; what changes is the number and intensity distribution of vibrational modes. They have another set of C–H bending bands near 7 micrometers, weaker than the stretching bands.<\/p>\n

Conversely, the 3–5 micrometer window does not contain only hydrocarbons; carbon dioxide’s 4.26 micrometer absorption also falls within it. In multi-component scenarios, filters must be matched to each target gas individually; a broad category cannot be packaged as one.<\/p>\n

Sulfur hexafluoride is another matter. Its ν\u2083 stretching band is near 10.55 micrometers, which is also the strongest in the entire mid-infrared region, with measured integrated absorption intensity more than an order of magnitude higher than the ν\u2084 bending band near 16 micrometers.<\/p>\n

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Gas imaging selects this band both because absorption is strong enough and because receiver response around 10 micrometers is good and atmospheric transmission is favorable. Although the 16 micrometer band exists, it falls in a region of strong atmospheric absorption and poor device response, so it is basically not used in engineering.<\/p>\n

Optical gas imaging uses a passive approach, relying on the portion of background radiation absorbed after passing through the gas cloud. According to the Lambert-Beer law, transmitted intensity decays exponentially with concentration and path length, written as I = I\u2080·exp(−α·c·L), where α is the absorption coefficient per unit concentration and unit path length at that wavelength, c is gas concentration, and L is path length. This formula describes only the attenuation term and does not include the gas’s own emission.<\/p>\n

The premise for this exponential form to hold is that concentration is uniform along the path. Real gas clouds are diffusing, with concentration varying along the line of sight; the rigorous form must be replaced by a path integral, I = I\u2080·exp(−α·∫c(l)dl). In engineering, the simplified form is still habitually used for order-of-magnitude estimation, but it must be clear that the reading corresponds to the concentration integral along the line of sight, not the concentration at a single point.<\/p>\n

Each pixel corresponds to a line-of-sight path. In the common configuration where background radiance is higher than that of the gas, the gas cloud absorbs part of the background radiation along this path, reducing the energy received by that pixel—this is how grayscale changes in the image arise.<\/p>\n

But what truly determines whether something can be seen in the image is the radiance difference, not absorption itself. A temperature difference—or more precisely, a radiance difference—must exist between the observed background and the gas for contrast to form in the image. When background temperature is higher than the gas, the gas absorbs background radiation and the plume appears as a dark region. When gas temperature is higher than the background, the gas cloud’s own emission exceeds the portion it absorbs, and the plume appears as a bright region.<\/p>\n

This difference determines an inherent limitation of OGI that cannot be avoided: when background temperature and gas temperature are close, contrast in the image approaches zero regardless of concentration. Seeing a plume from a chimney clearly against the ground is because the sky is a cold background; viewing leaks at similar temperatures within a cluster of equipment may produce the opposite effect. Understanding this prevents mistaking “not seen” for “no leak.”<\/p>\n

3. The Filter’s Role Is Part of Signal Definition<\/p>\n

Most of the radiation reaching the receiver is unrelated to the target gas. Solar reflection, the equipment’s own thermal radiation, and absorption by water vapor and carbon dioxide in the atmosphere all superimpose on the same optical path. The only way to extract the target gas’s absorption signal from this mixture is to place a filter with sufficiently narrow bandwidth in front of the receiver, allowing only light near the characteristic absorption band to pass.<\/p>\n

This step is not merely “filtering optimization”—it defines what counts as signal. With a wider bandwidth, more energy reaches the receiver and the image looks brighter, but the target absorption band’s share of total energy decreases, diluting the gas cloud’s contrast. With a narrower bandwidth, contrast improves, but received energy decreases and the noise proportion rises.<\/p>\n

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In the industry, narrowband filters for methane imaging typically have passband widths in the 100–200 nanometer range. This range is not arbitrary; it is a compromise found along a trade-off curve: wider, and the weight of the 3.2–3.4 micrometer absorption band is diluted; narrower, and available background radiation energy is insufficient, making weak leaks invisible. So the bandwidth parameter is not “narrower is better”—only “matched to the scenario.”<\/p>\n

Center wavelength position must also be precisely set. During coating design, the center wavelength is defined according to the absorption band position. In actual use, once the wavelength deviates, the radiance difference signal between the gas cloud and the background weakens—possibly to below the noise level—while the system reports no error. The operator simply sees “no leak this time.”<\/p>\n

This weakening is gradual, not switch-like. The filter passband is not an ideal rectangle; after center wavelength shift, as long as the passband edge still overlaps the absorption band, the signal will not drop to zero—it will only continue to weaken. This type of misjudgment is harder to troubleshoot than equipment failure because there is neither an error report nor a sudden change; sensitivity is lost bit by bit.<\/p>\n

Blocking depth is especially critical in such systems. Insufficient out-of-band suppression allows strong background radiation from non-target bands to leak in, directly raising the signal baseline and suppressing the tiny absorption difference of the gas cloud. Such systems face the background of an entire chemical plant site, with strong lights, heat sources, and reflective surfaces all within the field of view simultaneously. The cost of out-of-band leakage is higher than in imaging applications.<\/p>\n

4. Dual-Channel Design: What Does the Reference Band Solve?<\/p>\n

Many high-end models use a dual-filter wheel structure: one channel passes the target gas’s characteristic absorption band, and the other passes an adjacent reference band that the target gas does not absorb. The two channel images are differenced, preserving the gas cloud signal while canceling background non-uniformity.<\/p>\n

This design is the same type of approach as using a reference channel in gas detection to cancel light source attenuation. The difference is what the two must handle: in NDIR, the reference channel cancels light source intensity drift; here, the reference channel cancels spatial non-uniformity and temporal variation in background radiation. When sunlight is blocked by clouds or a distant hot device switches on or off, a single-channel image changes noticeably, while dual-channel differencing is much more stable.<\/p>\n

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The cost is a more complex optical structure. The filter wheel introduces moving parts, and there is a time difference during switching; in rapidly changing leak scenarios, the two channel images are not fully synchronized. Transmittance consistency between the two filters also becomes a new variable: if the attenuation characteristics of the two pieces are not synchronized, the differential result will slowly shift over time, manifesting as zero-point drift.<\/p>\n

This point is often overlooked during selection. The contrast advantage of dual-channel is explicit, but whether the batch consistency and temperature characteristics of the two filters match is an implicit metric that typically only becomes apparent during long-term use. Asking a supplier “by what criterion is the transmittance matching of the two filters controlled” reveals more about process capability than asking “how many ODs is the out-of-band suppression.”<\/p>\n

5. What the Standard’s Metrics Mean for Selection<\/p>\n

The channel count item directly determines how many gases the system can cover. A single channel with one filter corresponds to one characteristic absorption band of a certain gas; gases with dense rovibrational structure may cover multiple adjacent transitions within the same vibrational band in that range. Multiple channels can cover multiple gases or compare different absorption bands of one gas. More channels mean optical component count, alignment tolerances, and downstream processing circuits all increase simultaneously—cost does not rise linearly.<\/p>\n

The detection limit item best reveals differences. The detection limit given by gas imaging is commonly expressed in the industry as noise equivalent concentration length, in units of ppm·m, meaning the product of the minimum resolvable concentration and optical path at the current noise level. This value is simultaneously affected by receiver noise, optical system transmittance, and filter out-of-band suppression capability. It is the result of the entire chain, not determined by any single component alone.<\/p>\n

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The response delay item is related to frame rate but not equivalent. High frame rate only means fast acquisition; the processing chain from detection to alarm still includes identification, retrieval, and judgment steps. The first few seconds of a leak often carry the most information; if delay is prolonged, the diffusion range has already changed by the time the alarm arrives.<\/p>\n

The spatial pixel specification item is easily used for horizontal comparison, but its practical significance depends on your monitoring distance and range. Higher pixel count means more resolvable positions per unit field of view, but energy received per pixel decreases accordingly, which is not necessarily better in weak-signal scenarios. Pixel scale must be calculated together with lens focal length and monitoring distance; looking at a single number in isolation is meaningless.<\/p>\n

6. Where We Stand on This Path<\/p>\n

The core components of the spectral video technology route are the receiver, optical system, and algorithm. Filters account for a small proportion of the bill of materials, but they determine how much of the signal is contributed by the target gas. If this layer is not done well, no amount of downstream algorithm refinement can do more than search for signal in noise.<\/p>\n

MULTI IR specializes in coating design and volume coating of infrared filters. For mid-wave infrared gas imaging, our narrowband products can hold center wavelength tolerance within plus or minus 2 nanometers, control out-of-band suppression to OD4 or higher, and maintain average transmittance in the infrared band above 91%, suitable for both the 3–5 micrometer mid-wave and 8–14 micrometer long-wave windows.<\/p>\n

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There is a specific issue in dual-channel systems: transmittance matching between the two filters. This item is most easily overlooked during selection, yet it directly determines whether the differential result holds. Such paired components can be produced and supplied from the same coating batch, reducing attenuation characteristic differences between the two pieces at the source.<\/p>\n

With more channels, the problem shifts from pairing two pieces to comparability among multiple pieces. When three or four channels operate simultaneously, if the attenuation characteristics of any one channel are not synchronized with the others, the differential result will gradually lose meaning. This places batch consistency requirements an order of magnitude higher than single-channel systems. The systems MULTI IR has established in coating simulation, substrate control, and process data traceability correspond precisely to these needs.<\/p>\n

After a system-level standard is published, what propagates upstream is never simply “must meet the standard,” but a series of clauses specifying center wavelength tolerance, out-of-band suppression criteria, and how temperature drift coefficients should be agreed upon. How clearly these clauses are written will, years later, translate into differences in system manufacturers’ repair rates.<\/p>\n

Gas imaging has been on this path for more than twenty years, moving from laboratory demo images to a product category with unified performance criteria. What was crossed along the way was not only algorithms and devices but also an entire set of consensus on “what counts as qualified.” This is where the significance of standards lies: they give downstream procurement, acceptance, and regulation the same ruler.<\/p>\n

For upstream optical component makers, when the ruler changes, the requirements change with it. In the past, the comparison was whose curve looked better; in the future, the comparison will be whose curve still falls where originally promised after three years and after dozens of temperature cycling cycles. This layer of capability will not appear on the first page of any datasheet, but it determines who can stay on this chain for the long term.<\/p>\n

MULTI IR – National-level “Little Giant” Specialized and Sophisticated Enterprise. Over 10,000 types of infrared sensitive components in stock. Top 3 globally in comprehensive strength. Product portfolio covers infrared filters, optical coatings, infrared sensors, and other core categories. Lead drafter of the infrared filter industry standard.<\/p>\n

Website: www.mirhz.com<\/a> | Global Site: www.miroptech.com<\/a><\/p>\n

About Us<\/strong><\/p>\n

Founded in 2007, Hangzhou MULTI IR Technology Co., Ltd. is an optoelectronic technology enterprise integrating R&D, production, and sales. Its products are widely applied in aerospace, medical care, AR\/VR, display imaging, photography, and other fields, steadily holding the position of the world’s largest spot supplier of optical components.<\/p>\n

Media Contact<\/span>
Company Name:<\/strong> HANGZHOU MULTI IR TECHNOLOGY CO., LTD.<\/a>
Contact Person:<\/strong> Media Relations
Email:<\/strong> Send Email<\/a>
Country:<\/strong> China
Website:<\/strong> https:\/\/www.miroptech.com\/<\/a><\/p>\n

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Hangzhou City, Zhejiang Province, China – November 11, 2026 – Technical Standards Are Writing Quantitative Retrieval into Requirements: How Gas Imaging Is Evolving from a Tool into a Metrology Instrument Gas<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/www.olympiajournal.com\/news\/wp-json\/wp\/v2\/posts\/623430"}],"collection":[{"href":"https:\/\/www.olympiajournal.com\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.olympiajournal.com\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.olympiajournal.com\/news\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.olympiajournal.com\/news\/wp-json\/wp\/v2\/comments?post=623430"}],"version-history":[{"count":0,"href":"https:\/\/www.olympiajournal.com\/news\/wp-json\/wp\/v2\/posts\/623430\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.olympiajournal.com\/news\/wp-json\/wp\/v2\/media?parent=623430"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.olympiajournal.com\/news\/wp-json\/wp\/v2\/categories?post=623430"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.olympiajournal.com\/news\/wp-json\/wp\/v2\/tags?post=623430"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}