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D1003-21 解读
ASTM D1003-21 provides the standard procedures for evaluating haze and luminous transmittance of transparent plastics. Applicable primarily to planar sections of essentially transparent materials, this standard is essential for quality control in industries ranging from packaging to automotive glazing. It specifies two distinct test pathways: Procedure A using a hazemeter and Procedure B using a spectrophotometer. Critically, material having a haze value greater than 30% is considered diffusing and should be tested in accordance with Practice E2387 for goniometric optical scatter measurements. The values stated in SI units are to be regarded as standard.
📐 Scope and Key Terminology
This test method provides specific definitions to ensure repeatable quantification. Haze is defined as the scattering of light responsible for the reduction in contrast of objects viewed through the material. The specific angle for this standard is 0.044 rad (2.5°). Luminous transmittance is the ratio of the transmitted to incident luminous flux, weighted by the CIE spectral luminous efficiency function V(λ). Conditioning of test specimens prior to testing is mandatory per Practice D618. This standard replaces Method 3022 of Federal Test Method Standard 406 and is approved for use by agencies of the U.S. Department of Defense.
| 🟦 Parameter | 📏 Specification | 📐 Notes |
|---|---|---|
| Haze Definition Angle | 0.044 rad (2.5°) | Threshold for wide-angle forward scattering. |
| Diffusing Material Threshold | Haze > 30% | Refer to Practice E2387 for goniometric testing. |
| Primary Measured Values | Haze (%) & Luminous Transmittance (%) | Weighted by CIE standard observer V(λ). |
| Mandated Unit System | SI Units | Values stated in SI are regarded as standard. |
⚙️ Test Procedure Overview and Equipment
Two distinct instrumental procedures are detailed. Procedure A (Section 5) describes the setup and use of a standard hazemeter for the integrated measurement of haze and luminous transmittance. Procedure B (Section 8) details an alternative method utilizing a spectrophotometer. For materials that scatter a high percentage of light within a narrow forward angle (e.g., abraded transparent plastics), Test Method D1044 provides a method for greater discrimination. A critical note regarding international standards is that this test method is not equivalent to ISO 13468-1 or ISO/DIS 14782. Interlaboratory precision can be assessed using Practice E691.
🔍 Technical Tip — Abraded Specimens: For greater discrimination among materials that scatter a high percent of light within a narrow forward angle, such as is the case with abraded transparent plastics, adjust the hazemeter and perform measurements in accordance with Test Method D1044.
| ⚡ Procedure | 🎯 Equipment | 📌 Primary Application |
|---|---|---|
| Procedure A | Hazemeter (Section 5) | Routine quality control for standard clarity plastics. |
| Procedure B | Spectrophotometer (Section 8) | Detailed spectral analysis of transmitted light. |
| Alternate (High Haze) | Goniometer (Practice E2387) | Quantifying scatter in diffusing materials (>30% haze). |
⚠️ Standard Alert — ISO Equivalency: Note 2 of D1003-21 explicitly states this test method is not equivalent to ISO 13468-1 (Total Luminous Transmittance) or ISO/DIS 14782 (Haze of Transparent Materials). Practice E2935 should be used for conducting equivalence tests between testing processes.
📊 Significance and Use
Light that is scattered upon passing through a film or sheet of a material can produce a hazy or smoky field. This test method allows manufacturers to quantify these effects to ensure material performance meets specifications. The terminology used conforms to Standards D883 (Terminology Relating to Plastics) and E284 (Terminology of Appearance). The proper application of this standard is critical for maintaining consistent optical clarity in transparent materials.
❓ Frequently Asked Questions
🔍 What is the specific angle defining haze in D1003-21?
The standard specifies an angle of 0.044 rad (2.5°). Haze is calculated as the percentage of transmitted light that deviates from the incident beam by more than this angle.
💡 When should a spectrophotometer be used instead of a hazemeter?
Procedure B (Section 8) allows for the use of a spectrophotometer when detailed spectral data is required for analysis. For routine, rapid pass/fail testing or standard quality control of haze and transmittance, Procedure A with a dedicated hazemeter is typically preferred.
⚡ What is the scope limit for haze in this standard?
Materials with a haze value greater than 30% are considered diffusing. For these materials, D1003-21 directs the user to Practice E2387 for Goniometric Optical Scatter Measurements.
📌 Is D1003 equivalent to the ISO standards for haze and luminous transmittance?
No. Note 2 of the standard explicitly states that D1003 is not equivalent to ISO 13468-1 (total luminous transmittance) or ISO/DIS 14782 (haze).