What Is ASTM E1347 Tristimulus Colorimetry Color?
ASTM E1347-06(2020), Standard Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry, covers the instrumental measurement of color coordinates and color differences with a tristimulus colorimeter, also called a tristimulus filter colorimeter or color-difference meter. The method is active. It hasn’t been withdrawn. ASTM Committee E12 on Color and Appearance maintains it, in subcommittee E12.02, and the current version is the 2020 reapproval of the 2006 edition. Earlier editions, including the 2015 reapproval, are now historical.
Either reflected or transmitted light can be measured using a hemispherical optical system such as an integrating sphere or a bidirectional system such as 45:0 or 0:45 geometry. Which specimens? Generally, non-fluorescent, planar, object-color ones of all gloss levels. Retroreflective specimens and specimens with optical structure are a judgment call; users must decide whether the method suits them. For bidirectional geometry on retroreflective work, the standard points to Guide E179 and Practice E805.
A filter colorimeter has limited absolute accuracy. That’s why you standardize the instrument against a product standard when you need color coordinates. For color differences alone, the specimens should share similar spectral and geometric characteristics. Reflectance work can be standardized with a white reflectance standard; transmittance work uses an empty specimen position. There’s a limit, though. A tristimulus colorimeter cannot record a reflectance or transmittance curve, so it cannot reveal metamerism or paramerism. Spectrocolorimeters fall outside this standard and are addressed by Practice E1164, while Test Methods E1331 and E1349 cover reflectance factor and color by spectrophotometry with hemispherical and bidirectional geometry. Use those for spectral work.
Applications and Benefits of ASTM E1347 Tristimulus Colorimetry Color Testing
Scope
ASTM E1347 applies to the measurement of color differences using tristimulus values derived from standardized light sources and observer functions. It applies to opaque, translucent, and semi-transparent materials.
- Instrumental measurement of color coordinates and color differences using a tristimulus colorimeter is what the standard covers.
- You may also see the instrument called a tristimulus filter colorimeter or a color-difference meter.
- Reflected light or transmitted light can be measured.
- Accepted geometry? A hemispherical optical system, such as an integrating sphere.
- Bidirectional systems, such as annular, circumferential, or uniplanar 45:0 and 0:45 geometry, are also accepted.
- Generally suitable: non-fluorescent, planar, object-color specimens of all gloss levels.
- For retroreflective specimens or specimens with optical structures, suitability must be judged by the user.
- To get color coordinates, standardize with a product standard that closely matches the specimen’s spectral and geometric characteristics.
- Pairs of specimens with similar spectral and geometric characteristics are required for color-difference work, because the instrument cannot detect metamerism or paramerism.
- Out of scope: spectrocolorimeters, which Practice E1164 covers.
Applications
- Production-line color matching of paints, coatings, and painted panels against an approved product standard.
- Plastics, films, and molded parts coming in the door, when a quick color-difference reading is enough.
- Comparing one batch of pigments, inks, or printed and dyed goods with the next, as long as they share the same colorants.
- Flat textile, paper, and laminate samples, assessed for color difference.
- Color checks by transmittance on flat translucent or transparent specimens, where the geometry suits them.
- Routine quality control. A pass-or-fail decision is made against a customer-defined tolerance.
Benefits
- Fast, repeatable color-difference readings on flat specimens; no full spectral analysis needed.
- High-volume quality control suits it well, since the same product is measured against the same standard.
- You can pick hemispherical or bidirectional geometry to match the specimen and the way it is viewed.
- Numerical color data takes the place of subjective visual judgment.
- Routine comparisons cost less per measurement than a full spectrophotometric study.
- A documented, recognized basis for supplier and customer color agreements.
Our ASTM E1347 Testing Procedure
Sample Preparation
Prepare clean, uniform test and reference specimens.
1Instrument Calibration
Calibrate the colorimeter using certified reference standards.
2Color Measurement
Measure tristimulus values of both samples under defined lighting.
3Color Difference Calculation
Compute ΔE values to quantify color differences.
4ASTM E1347 Test Parameters and Requirements
| Parameter | Details |
|---|---|
| Measurement Principle | Tristimulus colorimetry |
| Light Source | Standard illuminants |
| Observer Angle | Standard 2° or 10° observer |
| Measurement Parameter | Color difference (ΔE) |
| Detector Type | Tristimulus photodetectors |
| Geometry | 45/0 or d/8 depending on instrument |
| Wavelength Range | Visible spectrum (approx. 400–700 nm) |
- Tristimulus filter colorimeter – Filtered light from the specimen goes in; color coordinates and color differences come out directly.
- Color-difference meter – A colorimeter configured to report differences between a specimen and a reference standard.
- Hemispherical geometry system – An integrating sphere collects reflected or transmitted light from the specimen.
- Bidirectional geometry system – Illumination and viewing happen at fixed angles such as 45:0 or 0:45.
- White reflectance standard – For standardizing the instrument on reflectance measurements.
- Product standard – A reference specimen with spectral and geometric characteristics close to the test specimens, used to standardize the instrument.
- Specimen holders and fixtures – Flat specimens stay positioned consistently over the measurement port.
Equipment and Instrumentation Used for ASTM E1347 Testing
What You Receive: Test Report, Data, and Certification
- Color coordinates for each specimen, measured against the product standard.
- How far each specimen sits from the reference, given as color-difference values.
- Which instrument, optical geometry, and standardization method were used.
- A specimen description, plus the number and position of readings taken.
- Where the customer provides tolerances, a comparison against them.
- A formal test report from Infinita Lab, with raw data available on request.
ASTM E1347 Tristimulus Colorimetry Color FAQs
ASTM E1347 is based on tristimulus colorimetry, which quantifies color using three values corresponding to human vision sensitivity. It measures color differences numerically, enabling objective comparison between a reference and a test sample under standardized illumination conditions.
Tristimulus colorimetry uses standardized observer functions and illuminants to replicate human visual perception mathematically. This reduces subjectivity, ensuring consistent and repeatable color measurements across different instruments, operators, and testing environments.
ΔE represents the numerical difference between two colors in a defined color space. It indicates whether the difference is perceptible to the human eye, helping manufacturers decide if a product meets color acceptance criteria or requires adjustment.
ΔE can be influenced by surface texture, lighting conditions, instrument calibration, and sample uniformity. Even small variations in measurement geometry or observer settings can affect the calculated color difference, requiring strict control of testing parameters.
Tristimulus data simplifies color representation into three values aligned with human vision, making it easier to compare and interpret color differences quickly while still maintaining accuracy.
ASTM E1347 measures color coordinates and color differences using a tristimulus colorimeter. The instrument measures reflected or transmitted light and converts the readings into color values to assess color consistency between specimens.
Why Choose Infinita Lab for Tristimulus Colorimetry Color Testing
When your Tristimulus Colorimetry Color results have to hold up - for compliance, a customer audit, or an engineering decision - ASTM E1347 accuracy and an unbiased third-party report matter more than price. Infinita Lab routes your ASTM E1347 tristimulus colorimetry color testing to ISO/IEC 17025-accredited U.S. partner labs with hands-on method experience, so you get defensible data, transparent reporting, and turnaround times built around your project deadline - not ours.
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