2024-12-20Industry Knowledge

ErP Directive (EU) 2019/2020 Light Source Functional Requirements: SVM and PstLM Explained

The ErP Directive (EU) 2019/2020 and Energy Label Directive (EU) 2019/2015 have been officially implemented, with new flicker testing requirements that many people are unsure how to test. The ErP Directive (EU) 2019/2020 has clear requirements for flicker testing, including two important indicators: SVM (Stroboscopic Effect Visibility Measure) and PstLM (Short-term Flicker Indicator). This article provides a detailed introduction to the basic concepts of ErP Directive flicker testing, ErP Directive (EU) 2019/2020 requirements, and how to test using flicker meters, helping readers understand and master ErP Directive SVM and PstLM flicker testing methods.

I. Basic Concepts of ErP Directive Flicker Testing

Flicker Index explanation diagram showing the area above the average level of light output divided by the total area of the light output waveform within one cycle of lighting product light output, IESNA standard flicker testing, flicker meter, Yiming Technology LFM-5000 flicker testing system, ErP flicker testing — **Figure 1:** Flicker Index Explanation - Area Above Average Level of Light Output Divided by Total Area of Light Output Waveform Within One Cycle, ErP Directive Flicker Testing Basic Parameter, IESNA Standard Flicker Testing, Yiming Technology LFM-5000 Flicker Meter can accurately measure Flicker Index

1. Flicker Index - ErP Directive Flicker Testing Basic Parameter

Standard Reference: Illuminating Engineering Society of North America (IESNA) 2000

Flicker Index is an important parameter in ErP Directive flicker testing, expressed as the area above the average level of light output divided by the total area of the light output waveform within one cycle of lighting product light output. Flicker Index is one of the basic indicators that need attention in ErP Directive (EU) 2019/2020 flicker testing, and can be accurately measured using professional flicker meters. The Flicker Index calculation formula is as follows:

Flicker Index calculation formula showing the area above the average level of light output divided by the total area of the light output waveform within one cycle, IESNA standard flicker testing, flicker meter, Yiming Technology LFM-5000 flicker testing system, ErP flicker testing — **Figure 2:** Flicker Index Calculation Formula - ErP Directive Flicker Testing Basic Parameter Calculation Method, IESNA Standard Flicker Testing, Yiming Technology LFM-5000 Flicker Meter can accurately measure Flicker Index, compliant with ErP Directive Flicker Testing Requirements

2. Percent Flicker and Modulation Depth - ErP Directive Flicker Testing Key Parameters

Standard Reference: CIE TN 006:2016 and IEEE Std 1789:2015 (Same Definition)

Percent Flicker and Modulation Depth are key parameters in ErP Directive flicker testing, referring to the ratio (multiplied by 100%) of the difference between the maximum and minimum light output levels to the sum of the maximum and minimum light output levels within one cycle of the light output waveform. Percent Flicker and Modulation Depth are important indicators that need to be measured in ErP Directive (EU) 2019/2020 flicker testing, and can be accurately obtained using professional flicker meters. The Percent Flicker and Modulation Depth calculation formula is as follows:

Percent Flicker and Modulation Depth calculation formula showing the ratio of the difference between maximum and minimum light output levels to their sum within one cycle of the light output waveform, CIE TN 006 2016 and IEEE Std 1789:2015 standards flicker testing, flicker meter, Yiming Technology LFM-5000 flicker testing system, ErP flicker testing — **Figure 3:** Percent Flicker and Modulation Depth Calculation Formula - ErP Directive Flicker Testing Key Parameter Calculation Method, CIE TN 006:2016 and IEEE Std 1789:2015 Standard Flicker Testing, Yiming Technology LFM-5000 Flicker Meter can accurately measure Percent Flicker and Modulation Depth, compliant with ErP Directive Flicker Testing Requirements

When percent flicker is below 3.2%, luminaires are in the no-flicker hazard range. When percent flicker is within 8% low-risk range, luminaire flicker is in the safe range. When conducting ErP Directive flicker testing using flicker meters, percent flicker is an important evaluation indicator.

Related Standard Requirements: Japanese Standard Requirement: Percent Flicker ≤5%; ErP Directive (EU) 2019/2020 requires PstLM≤1.0 and SVM≤0.4 (after September 1, 2024).

3. Pst Short-term Flicker Indicator - ErP Directive PstLM Testing Parameter

Definition: Pst short-term flicker indicator is an important parameter in ErP Directive flicker testing, referring to an indicator for evaluating flicker within a relatively short specified time interval at low frequencies (within 0.05-80Hz). Pst is a key indicator that needs to be measured in ErP Directive (EU) 2019/2020 flicker testing, and can be accurately measured using professional flicker meters.

Pst short-term flicker indicator explanation showing an indicator for evaluating flicker within a relatively short specified time interval at low frequencies within 0.05-80Hz range, IEC TR 61547-1:2020 standard flicker testing, PstLM measurement, flicker meter, Yiming Technology LFM-5000 flicker testing system, ErP flicker testing — **Figure 4:** Pst Short-term Flicker Indicator Explanation - ErP Directive PstLM Testing Parameter Definition, IEC TR 61547-1:2020 Standard Flicker Testing, Screenshot from IEC TR 61547-1:2020 Part 1 Section 3 Page 10 Clause 3.1.7, Yiming Technology LFM-5000 Flicker Meter can accurately measure Pst value, compliant with ErP Directive Flicker Testing Requirements

PstLM Definition: PstLM is a short-term flicker indicator measured with a light source flicker meter (Short-term Flicker Indicator measured with Light source flicker Meter). PstLM is a core indicator in ErP Directive (EU) 2019/2020 flicker testing, and can be accurately measured using professional flicker meters, compliant with IEC TR61547-1:2020 standard requirements.

PstLM short-term flicker indicator measured with light source flicker meter explanation showing the definition and measurement method of PstLM in IEC TR 61547-1:2020 standard, ErP flicker testing, flicker meter, Yiming Technology LFM-5000 flicker testing system, PstLM testing — **Figure 5:** PstLM Short-term Flicker Indicator Explanation - ErP Directive PstLM Testing Parameter Definition and Measurement Method, IEC TR 61547-1:2020 Standard Flicker Testing, Screenshot from IEC TR 61547-1:2020 Part 1 Section 3 Page 13 Section 3.3, Yiming Technology LFM-5000 Flicker Meter can accurately measure PstLM, compliant with ErP Directive (EU) 2019/2020 Flicker Testing Requirements

PstLM Detailed Explanation: The PstLM indicator proposed in IEC TR 61547-1:2020 is used to evaluate the visible flicker effects of lighting products caused by voltage fluctuations, covering frequencies from 0.05 to 80 Hz (low-frequency flicker). This indicator evaluates the severity of flicker during this period by simulating the subjective visual perception of illuminance fluctuations by the human eye and performing graded probability calculations of instantaneous flicker visual sensitivity. With PstLM = 1 as the limit, it indicates that under standard experimental conditions, 50% of experimenters (probability) just perceive flicker; when PstLM > 1, more than 50% of observers will perceive flicker. The ErP Directive (EU) 2019/2020 requires PstLM≤1.0, and PstLM is a key parameter that must be measured when conducting ErP Directive flicker testing using flicker meters.

4. SVM Stroboscopic Effect Visibility Measure - ErP Directive SVM Testing Parameter

Definition: SVM stroboscopic effect visibility measure is an important parameter in ErP Directive flicker testing, referring to an indicator calculated from light waveforms at high frequencies (between 80-2KHz) that indicates the threshold of stroboscopic effect visibility. SVM is a core indicator in ErP Directive (EU) 2019/2020 flicker testing, and can be accurately measured using professional flicker meters, compliant with CIE TN 006:2016 standard requirements.

SVM stroboscopic effect visibility measure explanation showing an indicator calculated from light waveforms at high frequencies between 80-2KHz that indicates the threshold of stroboscopic effect visibility, CIE TN 006:2016 standard flicker testing, SVM testing, flicker meter, Yiming Technology LFM-5000 flicker testing system, ErP flicker testing — **Figure 6:** SVM Stroboscopic Effect Visibility Measure Explanation - ErP Directive SVM Testing Parameter Definition and Measurement Method, CIE TN 006:2016 Standard Flicker Testing, Screenshot from CIE TN 006:2016 Part 4 Page 18 Table 1, Yiming Technology LFM-5000 Flicker Meter can accurately measure SVM, compliant with ErP Directive (EU) 2019/2020 Flicker Testing Requirements

SVM Detailed Explanation: The SVM indicator recommended in CIE TN 006:2016 is used for evaluating stroboscopic effects, covering frequencies from 80 to 2KHz (high-frequency flicker). The stroboscopic effect refers to the visual illusion where moving objects appear stationary or slow-moving when the light source flicker frequency is close to the moving object frequency, which may cause safety hazards in industrial environments. The visibility of stroboscopic effects is judged by SVM value: when SVM = 1, just visible (50% of observers can perceive); when SVM < 1, not visible (most observers cannot perceive); when SVM > 1, visible (most observers can clearly perceive). The ErP Directive (EU) 2019/2020 has strict requirements for SVM (SVM≤0.9 before September 1, 2024, or SVM≤0.4 after September 1, 2024 per (EU)2021/341 amendment), and SVM is a key parameter that must be measured when conducting ErP Directive flicker testing using flicker meters.

II. ErP Directive (EU) 2019/2020 Flicker Testing Requirements for SVM and PstLM

ErP Directive (EU) 2019/2020 flicker testing requirements for SVM and PstLM showing the limit requirements for SVM and PstLM in ErP Directive Table 4, PstLM≤1, SVM≤0.9 (before September 1, 2024), SVM≤0.4 (after September 1, 2024), flicker meter, Yiming Technology LFM-5000 flicker testing system, ErP flicker testing — **Figure 7:** ErP Directive (EU) 2019/2020 Flicker Testing Requirements for SVM and PstLM - ErP Directive Table 4 Limit Requirements for SVM and PstLM, PstLM≤1.0 (mandatory requirement), SVM≤0.9 (before September 1, 2024), Screenshot from (EU) 2019/2020 Page 19 Table 4, Yiming Technology LFM-5000 Flicker Meter compliant with ErP Directive Flicker Testing Requirements

ErP Directive (EU) 2021/341 Ecodesign Regulation Annex IV SVM amendment requirements showing the amendment requirement of SVM≤0.4 after September 1, 2024, ErP flicker testing update, flicker meter, Yiming Technology LFM-5000 flicker testing system, SVM testing — **Figure 8:** ErP Directive SVM Amendment Requirements - ErP Directive (EU) 2021/341 Ecodesign Regulation Annex IV SVM Amendment Requirements, SVM≤0.4 Amendment Requirement After September 1, 2024, Screenshot from (EU) 2021/341 Ecodesign Regulation Annex IV, Yiming Technology LFM-5000 Flicker Meter compliant with ErP Directive SVM Testing Requirements

From the above figures, we can see the ErP Directive (EU) 2019/2020 flicker testing requirements for SVM and PstLM: PstLM≤1.0 (mandatory requirement); SVM≤0.9 (before September 1, 2024, transitional requirement); SVM≤0.4 (after September 1, 2024, per (EU)2021/341 amendment). These ErP Directive flicker testing requirements need to be verified through professional flicker meters, compliant with CIE TN 006:2016 and IEC TR61547-1:2020 standard requirements.

III. How to Obtain SVM and PstLM Using Flicker Meters? - ErP Directive Flicker Testing Method

After testing photometric data with a light source flicker meter, SVM can be obtained through CIE TN 006:2016 standard measurement, and PstLM can be obtained through IEC TR61547-1:2020 standard measurement. Professional flicker meters are essential equipment for conducting ErP Directive (EU) 2019/2020 flicker testing. Yiming Technology LFM-5000 flicker meter can accurately measure ErP Directive flicker testing parameters such as SVM and PstLM, fully compliant with CIE TN 006:2016 and IEC TR61547-1:2020 standard requirements, as shown in the figures below:

PstLM short-term flicker indicator testing method showing obtaining PstLM through IEC TR61547-1:2020 measurement after testing photometric data with light source flicker meter, ErP flicker testing process, flicker meter, Yiming Technology LFM-5000 flicker testing system, PstLM testing — **Figure 9:** PstLM Testing Method - ErP Directive PstLM Testing Process, Obtaining PstLM Through IEC TR61547-1:2020 Standard Measurement After Testing Photometric Data with Light Source Flicker Meter, Yiming Technology LFM-5000 Flicker Meter can accurately measure PstLM, compliant with ErP Directive (EU) 2019/2020 Flicker Testing Requirements

Summary

The ErP Directive (EU) 2019/2020 and Energy Label Directive (EU) 2019/2015 have been officially implemented, with new flicker testing requirements including two important indicators: SVM and PstLM. This article provides a detailed introduction to the basic concepts of ErP Directive flicker testing, including the definitions and calculation methods of key parameters such as Flicker Index, Percent Flicker and Modulation Depth, Pst short-term flicker indicator, and SVM stroboscopic effect visibility measure. ErP Directive flicker testing is an important part of ErP Directive compliance and requires the use of professional flicker meters, compliant with CIE TN 006:2016 and IEC TR61547-1:2020 standard requirements.

The ErP Directive (EU) 2019/2020 has clear flicker testing requirements for SVM and PstLM: PstLM≤1.0 (mandatory requirement); SVM≤0.9 (before September 1, 2024, transitional requirement); SVM≤0.4 (after September 1, 2024, per (EU)2021/341 amendment). These ErP Directive flicker testing requirements ensure that lighting products do not cause flicker hazards to human health. After testing photometric data with a light source flicker meter, SVM can be obtained through CIE TN 006:2016 standard measurement, and PstLM can be obtained through IEC TR61547-1:2020 standard measurement, thereby evaluating whether products meet ErP Directive (EU) 2019/2020 requirements.

As a professional LED lighting testing equipment manufacturer, Yiming Technology deeply understands the importance of ErP Directive (EU) 2019/2020 flicker testing requirements and has developed the professional LFM-5000 flicker meter, which can accurately measure ErP Directive flicker testing parameters such as SVM, PstLM, Flicker Index, Percent Flicker, and Modulation Depth, helping enterprises successfully complete ErP Directive flicker testing. Yiming Technology LFM-5000 flicker meter fully complies with CIE TN 006:2016 and IEC TR61547-1:2020 standard requirements and can accurately evaluate the flicker performance of lighting products, providing reliable basis for product quality control. Yiming Technology is committed to providing professional ErP Directive flicker testing services and LFM-5000 flicker meters for customers, jointly promoting the standardized development of the lighting industry.