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Understanding CSA EXP 248-15 (2018): The Experimental Standard for Solid-State Lighting Photometric Performance
Scope, Testing Requirements, and Compliance Guidance for CSA’s Experimental Standard on Photometric and Colorimetric Performance of SSL Products
CSA EXP 248-15 (2018) is an experimental standard developed by the Canadian Standards Association (CSA Group) to address the rising need for consistent, reproducible photometric and colorimetric testing of solid-state lighting (SSL) products. As an “EXP” document, it reflects a forward-looking, practical approach to evaluating performance parameters that are not fully covered by traditional North American or international standards. The 2018 reaffirmation maintains the original 2015 technical content while confirming its relevance to the evolving LED luminaire market.
Scope and Application
The standard defines uniform test methods and reporting requirements for measuring the photometric and colorimetric performance of SSL products—including LED lamps, integrated LED luminaires, and retrofit kits. It covers:
- Total luminous flux measurement (in lumens)
- Efficacy (lumens per watt)
- Correlated color temperature (CCT) and Duv (chromaticity distance from the blackbody locus)
- Color rendering metrics (CRI, R9, and optional TM-30 metrics)
- Lumen maintenance projection (based on TM-21 calculations)
The experimental standard applies to products rated for operation in indoor, outdoor, and damp or wet locations, provided they are powered by AC or DC sources up to 600 V. It specifically excludes HID, fluorescent, and incandescent sources.
Experimental Status: As an experimental standard, CSA EXP 248-15 (2018) has not undergone the full consensus process of a National Standard of Canada. It is intended for early adoption by manufacturers, testing labs, and specifiers to gain experience with advanced SSL performance metrics before they are incorporated into a formal standard.
Technical Requirements
CSA EXP 248-15 prescribes strict environmental and equipment conditions for photometric laboratories. It distinguishes between two test methods:
Method A – Integrating Sphere
Used for total luminous flux, chromaticity, and color rendering measurements. The sphere must meet the geometry requirements of IES LM‑79 (e.g., 4π or 2π configuration) and be coated with a high‑reflectance, spectrally neutral material. Self‑absorption correction is mandatory for any auxiliary lamp inside the sphere.
Method B – Goniophotometer
Required when spatial luminous intensity distribution is needed (e.g., for luminaire classification in IES files). The standard specifies minimum angular resolution, positioning accuracy, and dark‑room conditions.
The following table summarises the key photometric performance classes defined in the standard for six common SSL product categories.
| Category | Minimum Luminous Flux (lm) | Efficacy (lm/W) | CCT Range (K) | Minimum CRI | Lumen Maintenance @ 6k h (%) |
|---|---|---|---|---|---|
| A-Lamp | 800 | 110 | 2700–5000 | 80 | 96.0 |
| Decorative Bulb | 350 | 70 | 2200–3000 | 80 | 90.0 |
| Downlight (integrated) | 1000 | 100 | 2700–4000 | 90 | 95.0 |
| Linear Replacement (T8) | 1800 | 130 | 3000–5000 | 80 | 97.0 |
| Outdoor Wall Pack | 2000 | 100 | 3000–4000 | 70 | 92.0 |
| Retrofit Kit (Downlight) | 650 | 85 | 2700–4000 | 80 | 94.0 |
Table 1 – Minimum photometric and colorimetric performance criteria for representative SSL product categories (sample values for illustration; refer to the standard for the complete classification).
Color Maintenance and Chromaticity Tolerance
The standard introduces an annealing test for chromaticity stability: samples must be operated at rated current for 1000 h and then evaluated for Δu′v′ shift. The allowable tolerance is < 0.002 for products claiming tuned CCT and < 0.004 for standard colour versions. This requirement is stricter than typical ENERGY STAR® stipulations and reflects the experimental nature of the document.
Measurement Conditions: Ambient temperature must be 25 °C ± 1 °C with minimal airflow. The stabilization time for SSL products is at least 30 minutes (or until flux variation over a 15‑minute interval is less than 0.5 %). Do not use switch‑cycling during stabilization unless specifically required by the test plan.
Implementation Highlights
Because CSA EXP 248-15 is an experimental standard, it carries distinct implementation considerations.
- Voluntary adoption: The standard is not mandated by any Canadian jurisdiction. However, several demonstration projects (e.g., BC Hydro’s technology trials) have referenced EXP 248 as a baseline for prototype evaluation.
- Reporting flexibility: Manufacturers can choose to report only the metrics that apply to their product. For instance, a lumen‑maintenance projection is not required for products that carry a 5‑year or shorter warranty.
- Bridge to future standards: The experimental status allows CSA to adjust the requirements in future editions (expected to become a full CSA standard or be harmonized with UL 1598 / CAN/CSA‑C22.2 No. 250.14).
Proactive Compliance: Testing to EXP 248‑15 can differentiate a product in the marketplace. Early adopters have reported improved acceptance by large‑scale specifiers who value transparent, repeatable photometric data aligned with advanced metrics like TM‑30 and TM‑21.
Compliance and Certification Notes
CSA Group does not currently offer a formal certification mark based solely on EXP 248‑15. However, a manufacturer may:
- Perform self‑testing (in an ISO 17025‑accredited lab) and issue a “Claim of Compliance” document.
- Engage a third‑party lab to verify the results and produce a letter of attestation.
- Use the data as input for an ENERGY STAR® or DesignLights Consortium® submission, provided that the testing methods are harmonized with the relevant program requirements.
A key compliance note is that the standard permits the use of “accelerated testing” for lumen maintenance (see TM‑21 correlation). The test duration must be at least 3,000 h for the 6,000‑h projection, and at least 6,000 h for the 25,000‑h projection. If the sample experiences a catastrophic failure (flux drop > 30 %), the projection is invalid and the product should be re‑evaluated.
Important: The experimental standard does not supersede any safety standard (e.g., CAN/CSA‑C22.2 No. 250.0, UL 1598). All SSL products must still comply with applicable safety and environmental regulations before being sold in Canada.
Frequently Asked Questions
Q: What does the “EXP” designation mean, and how does it affect legal acceptance?
A: “EXP” stands for “Experimental Standard.” Such documents are developed under special procedures that include public review but not the full consensus process required for National Standards of Canada. Therefore, they do not have regulatory force. Nevertheless, they can be invoked in industry specifications, government procurement, or private certification programs.
A: “EXP” stands for “Experimental Standard.” Such documents are developed under special procedures that include public review but not the full consensus process required for National Standards of Canada. Therefore, they do not have regulatory force. Nevertheless, they can be invoked in industry specifications, government procurement, or private certification programs.
Q: Can I use CSA EXP 248‑15 (2018) as an alternative to IES LM‑79 for US market entry?
A: The standard is largely harmonized with IES LM‑79 in terms of measurement methods (integrating sphere, goniophotometer). For US market acceptance (e.g., ENERGY STAR), it is safer to use LM‑79 directly because it is explicitly referenced by US programs. However, EXP 248 may be accepted if the testing lab documents equivalence.
A: The standard is largely harmonized with IES LM‑79 in terms of measurement methods (integrating sphere, goniophotometer). For US market acceptance (e.g., ENERGY STAR), it is safer to use LM‑79 directly because it is explicitly referenced by US programs. However, EXP 248 may be accepted if the testing lab documents equivalence.
Q: Does the experimental standard cover light spectrum or flicker?
A: No. CSA EXP 248‑15 (2018) focuses solely on photometric and colorimetric steady‑state performance. Flicker, stroboscopic effects, and spectral power distribution beyond color metrics are not addressed. For those aspects, refer to IEC TR 63158 or IEEE 1789.
A: No. CSA EXP 248‑15 (2018) focuses solely on photometric and colorimetric steady‑state performance. Flicker, stroboscopic effects, and spectral power distribution beyond color metrics are not addressed. For those aspects, refer to IEC TR 63158 or IEEE 1789.
Q: Is there a plan to update this experimental standard or convert it into a full standard?
A: CSA Group has indicated that the content of EXP 248‑15 will be used as the basis for a new edition of CSA C860, which is the full standard for lighting product performance. The 2018 reaffirmation suggests that version is still current, but a formal revision is expected by 2027.
A: CSA Group has indicated that the content of EXP 248‑15 will be used as the basis for a new edition of CSA C860, which is the full standard for lighting product performance. The 2018 reaffirmation suggests that version is still current, but a formal revision is expected by 2027.
Document reference: CSA EXP 248‑15 (R2018). For the authoritative text, consult the CSA Group official publication.
This article provides general technical information and should not be considered legal or certification advice. Always check the current edition of the standard and consult with accredited testing bodies.
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