Through-glass measurement with infrared thermal imaging

Measurement in Ranges with High Emissivity Reduce Measurement Error

Emissivity values of materials greatly vary throughout the infrared spectrum. Concentrating the thermographic measurements on spectral ranges with an explicitly high or low emissivity can lead to detection of special effects. Spectral filters integrated in infrared camera systems allow the distinct transmission or blocking of radiation of selected IR ranges with the object’s high emissivity or high transmission. Thus, disturbing background radiation can be minimized and measurement errors reduced.

Users, who choose dedicated filter parameters, can e.g., measure and inspect the inside wall of a furnace whilst the burning gas is not detected due to the used filter – a typical measurement through gas. Another setting of the filter parameters can reduce the effect of the background radiation when measuring thin plastic foils to really measure the foil temperature itself.

thermal imaging of a lamp with a through-glass filter

Measurement of Ranges with High Transmission

Concentrating on spectral ranges at which the transmission of the material is especially high allow for doing thermographic measurements of objects behind the material. The filament of a lamp can be measured without being influenced by the manifold colder glass of the lamp. The same holds true measuring objects behind flames.

Associated Thermographic Automation Solutions

  • Automation InfraTec INDU-SCAN - In-process industrial temperature measurement
    Process Control - INDU-SCAN

    Process Control - INDU-SCAN

    Contactless measurement of temperature distributions and profiles with industrial thermographic cameras permits efficient monitoring and control of temperature-dependent processes and procedures within a system-integrated quality assurance programme in industry.

  • Quality Assurance for Coating Processes | InfraTec / Picture Credits: © / Greppe
    Quality Assur­ance for Coating Processes - LayIR-CHECK

    Quality Assur­ance for Coating Processes - LayIR-CHECK

    Infrared cameras allow the non-destructive and process-synchronous monitoring of coating processes to ensure that the coatings are free of defects as soon as they are applied.

  • PV-LIT test solution for solar cells
    Photovoltaic Test System - PV-LIT

    Photovoltaic Test System - PV-LIT

    Get advantages in costing and quality by non-contact thermographic testing of your solar cells and PV-modules.

Advantages of this Thermography Solutions in this Application

  • InfraTec glossary - Rotating filter- und aperture wheel
    Get further information about the separate filter & aperture wheel

    Separate Filter & Aperture Wheel – Spectral Thermography

    The combination of a separate filter and aperture wheel, allowing a total of 30 freely selectable combinations, is prerequisite for an universal application in measurement tasks with high object temperatures and in the field of spectral thermography. The neutral density filters used for signal attenuation or the combination of spectral filters and apertures reliably prevent interference effects.

  • Thermal image during ignition of an airbag Image Small
    Further information about subwindowing

    Window Mode (Subwindowing) – Capture of Rapid Sequences

    The thermal imaging camera can be operated in full, half, quarter and sub mode. With the camera control software, it is possible to use the extended subwindowing function. Using click-and-drag, freely definable sections can be set up quickly and conveniently. A defined sub-frame of the detector is picked out to achieve these extremely high refresh rates.

  • Further information about lenses

    High-performance Full Optics

    High quality precision lenses allow the adaptation of the image geometry to almost every measuring situation. Its performance parameters are calibrated with respect to functionality, quality and flexible application. Due to proper IR-transparent lens materials and high-precision antireflexion coating, the lenses are optimised for different spectral ranges.

  • Further information about HDR-function

    HDR – Simultaneous Mapping of Wide Temperature Ranges

    The High Dynamic Range (HDR) function of the Infrared ImageIR® camera series enables measurement scenarios with extremely different temperatures to be recorded continuously. When recording in HDR mode, multiple thermograms with different integration times and different filters are recorded quickly in succession and compiled into an overall image with a high dynamic range. The measuring range can span up to 1,500 K. Users obtain high-contrast images in a wide temperature range characterized by high measurement accuracy.

  • Thermografie-Kameraserie ImageIR® mit neuer 10 GigE-Schnittstelle
    Further information about the 10 GigE technology

    10 GigE Interface for a Strong Increase in Output

    The 10 Gigabit Ethernet interface of the high-end camera series ImageIR® opens this extremely fast transmission standard with a NIC specially developed by InfraTec. This works with optical or electrical transceiver modules that are easy to change and are called SFP+.

    Different 10 GigE fiber SFP+ transceivers allow transmission ranges of up to ten kilometers with the same low sensitivity to electromagnetic interference. A corresponding standard SFP ensures backward compatibility with the conventional GigE interface. This combination allows the ease of use of the cameras with the 10 Gigabit Ethernet interface in existing systems - though at a reduced transmission rate.

  • InfraTec thermography - Thermal resolution

    Thermal Resolution – Determination of Differences of Only a Few Millikelvin

    For detection of small temperature changes InfraTec's infrared cameras offer thermal resolutions up to < 15 mK in real-time operation. By using the Lock-in Thermography method it is possible to further increase this resolution significantly. For this purpose test objects are periodically excited and non-destructively examined for defects and irregularities.

Get in contact with InfraTec thermography division

Would You Like to Know More?

It is not unusual for tasks to be associated with special requirements. Discuss your specific application needs with our specialists, receive further technical information or learn more about our additional services.

United States

InfraTec infrared LLC
75024 Plano, TXUSA

Wide Range of Spectral Filters for Mounting Close to the Detector

InfraTec offers a wide range of special spectral filters for thermographic measurement of the most different materials and applications. Those filters can also be customized. Both the infared camera systems of the ImageIR ® series as well as the long-wave uncooled VarioCAM ® hr head cameras provide facilities for a mounting close to the detector within a filter wheel or a filter slider. The filter wheel of the ImageIR ® models is especially convenient as filters can be changed remotely controlled and motorized. Warm aperture effects caused by a filter position in front of the lens and resulting in possibly big measurement errors can be avoided by such positioning close to the detector being possible in infrared camera systems of InfraTec.

Spectral infrared thermal imaging to monitor the film production

Applications of Spectral Thermography

Besides the "on-glass" and "through-glass" measurement exists a number of other applications in different industrial sectors as well as in the field of research and development:

  • IR-reflectography
    IR-reflectography is used for the detection of lower painting layers due to its spectral behaviour (upper layer transmissive, lower drawings reflective).
  • Humidity detection
    With the help of humidity detection, for example for the analysis of building materials in case of claims, the spectral absorption factor of water band is defined.
  • Leakage
    Another interesting application is the detection of leakages on tanks using IR-detectable gases. A suitable and available gas is CO2, having a strong absorption band at 4,25 μm. A tempered background helps to recognize the leaving gas flow.
  • Temperature measurement of flames
    Temperature of flames can be estimated by measuring selectively within the absorption band of CO2 at 4.25 μm. Thermography at objects behind the flame is possible using the spectral range of (3.75 … 4) μm (for example furnace walls or pipes).
  • Film extrusion process
    Film surface temperature can be measured using a band pass filter at 3.4 μm (applicable for various plastics, e.g. polyethylene, polypropylene, polyamide, polyvinyl). For some plastics an absorption band at 8 μm (LWIR) can be used.

Associated Industries & Applications

  • thermal imaging for automotive applications
    Automotive Industry

    Automotive Industry

    Infrared camera systems help you to secure a high product quality in production and at your suppliers.

  • thermography for aerial photography
    Aerial Thermography

    Aerial Thermography

    Detect persons and objects in the field or monitor wide-area geologic properties or environmental damages.

  • thermal imaging in metallurgy


    Efficiently reduce the energy consumption of your metallurgic processes using infrared camera systems.

  • thermal imaging in chemical industry
    Chemical Industry

    Chemical Industry

    Systematically control reactive process heat and display with infrared camera systems of InfraTec.

  • thermal imaging in plastic industry
    Plastics Industry

    Plastics Industry

    Cost-efficiently control die-casting and extrusion processes by means of infrared camera systems.

  • thermal imaging in glass industry
    Glass Industry

    Glass Industry

    Measure correctly temperature distributions behind and on glass by using selected spectral filters.

  • thermal imaging for environmental studies
    Environmental Studies

    Environmental Studies

    Look for smallest temperature differences in landscapes, biotopes and labs using infrared camera models of highest measurement precision.

  • Active Thermography - Picture Credits: © Rainer /
    Active Thermography

    Active Thermography

    Make use of active thermography for non-destructive and contact-free material testing, for both automated inline and offline solutions.

  • high-speed thermography
    High-Speed Thermography

    High-Speed Thermography

    Get even faster and analyze temperatures at highest process speeds.

  • InfraTec Bondung and Sealing - Hot gas
    Bonding and Sealing

    Bonding and Sealing

    Users can utilise infrared cameras during bonding and sealing to monitor and control various technological parameters. This includes the geometry of the adhesive application, adhesive temperature and adherend temperature, curing temperature as well as the adhesive bond.

  • thermal imaging for material testing
    Material Testing

    Material Testing

    Save time and costs by non-destructively testing components with infrared camera systems by InfraTec.

  • thermal imaging in aviation
    Aerospace Industry

    Aerospace Industry

    Comply with highest security demands by applying state-of-the-art infrared camera systems.

  • InfraTec - Additive manufacturing for process control
    Additive Manufacturing

    Additive Manufacturing

    By in-line monitoring of thermal process parameters, infrared cameras from InfraTec support the optimisation of additive manufacturing processes.

  • Laser Industry

    Laser Industry

    High-end thermography in heat-generating laser applications in materials processing.

Publications by our Customers

Thermal performance of a solar high temperature thermochemical reactor powered by a solar simulator

Infrared camera: VarioCAM® HD head 900

Infrared Cameras for Spectral Thermography Applications