Each discipline in thermography has standards and guidelines that guide the application of the technology. Standards and guidelines in thermography are developed through research and field experience. Each discipline in thermography is expected to adhere to the standards and guidelines in their respective fields.
The following information is provided as reference for the use of thermal imaging in buildings. The information is based on a review of the current and past literature, standards and guidelines issued by other organizations concerning the application of thermal imaging. It is not the purpose of this organization to regulate building thermography, but rather to promote scientific validity and quality imaging. The information that follows has been compiled to provide useful information into the use of infrared thermography for building applications.
ORGANIZATIONS
Thermography Standards Developing Organizations
- ASTM International (ASTM)
- ASNT – The American Society for Non Destructive Testing (NDT)
- IEC – The International Electrotechnical Commission
- Infraspection Institute Standards
- ISO – The International Organization for Standardization
- LETA – The Law Enforcement Thermographers’ Association
- OIML – The International Organization of Legal Metrology (Organisation Internationale de Métrologie Légale)
- RESNET
INTERNATIONAL
ISO 6781:1983 Thermal insulation — Qualitative detection of thermal irregularities in building envelopes — Infrared method Specifies a qualitative method, by thermographic examination (infrared method), for detecting thermal irregularities in building envelopes. The method is used to identify wide variations in the thermal properties, including air tightness, of the components constituting the external envelopes of buildings. Does not apply to the determination of the degree of thermal insulation and air tightness of a structure.
ISO 10878:2013 Non-destructive testing — Infrared thermography — Vocabulary
Defines terms used in infrared thermography for non-destructive testing and forms a common basis for standard general use.
UNITED STATES
ANSI-ASHRAE 101-1981 Application of Infrared Sensing Devices to the Assessment of Building Heat Loss Characteristics.
(Withdrawn 6/1989 because ASTM standard is preferred)
ASHRAE 105-2007 (Supersedes 105-1984) Standard Methods of Measuring and Expressing Building Energy Performance This standard is intended to foster a commonality in reporting the energy performance of existing or proposed buildings to facilitate comparison, design and operation improvements, and development of building energy performance standards. It provides a consistent method of measuring, expressing, and comparing the energy performance of buildings. This revision of ANSI/ASHRAE Standard 105-1984 provides a method of energy performance comparison that can be used for any building, proposed or existing, and that allows different methods of energy analysis to be compared. Historically Standard 105 has provided a basis for reporting energy use, with only limited ability to express or compare building energy performance. This version of Standard 105 extends the reach considerably and is intended to provide a common basis for reporting building energy use, expressions of energy performance, and comparisons of energy performance.
ASNT-SNT-TC-1A recommendations for thermal/infrared testing, as established by the American Society for Non-Destructive Testing (ASNT). Personnel Qualification and Certification in Nondestructive Testing (2006) provides guidelines for employers wishing to establish in-house certification programs. SNT-TC-1A establishes the general framework for a qualification and certification program.
In addition, the document provides recommended educational, experience and training requirements for the different test methods.
ASTM C1046 Standard Practice for In-Situ Measurement of Heat Flux and Temperature on Building Envelope Components This practice covers a technique for using heat flux transducers (HFTs) and temperature transducers (TTs) in measurements of the in-situ dynamic or steady-state thermal behavior of opaque components of building envelopes.
ASTM C1060 Standard Practice for Thermographic Inspection of Insulation Installations in Envelope Cavities of Frame Buildings This describes the techniques to conduct qualitative thermal inspections of building walls, ceilings, roofs and floors that may contain insulation in the stud bays.
5.1 Although infrared imaging systems have the potential to determine many factors concerning the thermal performance of a wall, roof, floor, or ceiling, the emphasis in this practice is on determining whether insulation is missing or whether an insulation installation is malfunctioning. Anomalous thermal images from other apparent causes are not required to be recorded; however, if recorded as supplemental information, their interpretation is capable of requiring procedures and techniques not presented in this practice.
ASTM C 1153 Standard Practice for Location of Wet Insulation in Roofing Systems Using Infrared Imaging This describes the techniques used to determine the location of wet insulation in roofing systems.
ASTM C1155 Standard Practice for Determining Thermal Resistance of Building Envelope Components from the In-Situ Data This practice covers how to obtain and use data from in-situ measurement of temperatures and heat fluxes on building envelopes to compute thermal resistance. Thermal resistance is defined in Terminology C168 in terms of steady-state conditions only.
ASTM D4788 Standard Test Method for Detecting Delaminations in Bridge Decks Using Infrared Thermography This test method describes how infrared thermography is used for delamination determinations of portland cement concrete bridge decks.
ASTM E1213 Standard Test Method for Minimum Resolvable Temperature Difference for Thermal Imaging Systems This test method describes the process to determine the minimum resolvable temperature difference (MRTD) capability of the compound observer thermal imaging system as a function of spatial frequency.
ASTM E1256 Standard Test Methods for Radiation Thermometers (Single Waveband Type) The methods described in these tests can be utilized to evaluate the following six basic operational parameters of a radiation thermometer (single waveband type): Section Calibration Accuracy 7 Repeatability 8 Target Size 9 Response Time 10 Warm-Up Time 11 Long-Term Drift.
ASTM E1311 Standard Test Method for Minimum Detectable Temperature Difference for Thermal Imaging Systems This test method gives a measure of a thermal imaging system’s effectiveness for detecting a small spot within a large background. Thus, it relates to the detection of small material defects such as voids, pits, cracks, inclusions, and occlusions. MDTD values provide estimates of detection capability.
ASTM C1371 Standard Test Method for Determination of Emittance of Materials Near Room Temperature Using Portable Emissometers This test method covers a technique for determination of the emittance of typical materials using a portable differential thermopile emissometer. The purpose of the test method is to provide a comparative means of quantifying the emittance of opaque, highly thermally conductive materials near room temperature as a parameter in evaluating temperatures, heat flows, and derived thermal resistances of materials.
This test method does not supplant Test Method C835, which is an absolute method for determination of total hemispherical emittance, or Test Method E408, which includes two comparative methods for determination of total normal emittance. Because of the unique construction of the portable emissometer, it can be calibrated to measure the total hemispherical emittance. This is supported by comparison of emissometer measurements with those of Test Method C835.
ASTM E1311 Standard Test Method for Minimum Detectable Temperature Difference for Thermal Imaging Systems This test method covers the determination of the minimum detectable temperature difference (MDTD) capability of a compound observer-thermal imaging system as a function of the angle subtended by the target.
ASTM E1543 Standard Test Method for Noise Equivalent Temperature Difference of Thermal Imaging Systems This test method gives an objective measure of the temperature sensitivity of a thermal imaging system (relative to a standard reference filter) exclusive of a monitor, with emphasis on the detector(s) and preamplifier.
Note1—Test values obtained under idealized laboratory conditions may or may not correlate directly with service performance.
This test method affords a convenient means for periodically monitoring the performance of a given thermal imaging system.
NETD relates to minimum resolvable temperature difference as described in Test Method E1213. Thus, an increase in NETD may be manifest as a loss of detail in imagery. Intercomparisons based solely on NETD figures may be misleading.
Note2—NETD depends on various factors such as spectral bandwidth and background temperature.
ASTM E1862 Standard Test Methods for Measuring and Compensating for Reflected Temperature Using Infrared Imaging Radiometers This test method describes procedures for measuring and compensating for reflected temperature when measuring the surface temperature of a specimen with an infrared imaging radiometer.
ASTM E1897 -14(2018) Standard Test Methods for Measuring and Compensating for Transmittance of an Attenuating Medium Using Infrared Imaging Radiometers The transmittance of an attenuating medium can cause errors for an infrared thermographer using an infrared imaging radiometer to measure the temperature of a specimen through the medium. Three test methods are given for measuring and compensating for this error source. A test method is given for measuring the transmittance of an attenuating medium.
ASTM E1933 Standard Test Methods for Measuring and Compensating for Emissivity Using Infrared Imaging Radiometers This test method describe procedures for measuring and compensating for emissivity when measuring the surface temperatures of a specimen with an infrared imaging radiometer.
ASTM E2018 Standard Guide for Property Condition Assessments: Baseline Property Condition Assessment Process The purpose of this guide is to define good commercial and customary practice in the United States of America for conducting a baseline property condition assessment (PCA) of the improvements located on a parcel of commercial real estate by performing a walk-through survey and conducting research as outlined within this guide.
ASTM E2758-10 Standard Guide for Selection and Use of Wideband, Low Temperature Infrared Thermometers This guide covers electronic instruments intended for measurement of temperature by detecting intensity of thermal radiation exchanged between the subject of measurement and the sensor. The devices covered by this guide are referred to as IR thermometers.