ISD-100HF-BTS256-LED

The BTS256-LED light meter

In its standalone mode, the compact BTS256-LED meter is designed for the convenient measurement of luminous flux, spectrum, color, and color rendering index of single LEDs. A key feature is the conical measurement port at the entry of the internal integrating sphere which enables the measurement of onboard LEDs. The bayonet connector used to attach the conical adapter makes it possible to combine the BTS256-LED with other accessory components. Gigahertz-Optik offers different accessories as part of the BTS256-LED Plus Concept which greatly extends the measurement capabilities of the BTS256-LED.

Enhancement of the BTS256-LED using the ISD-100HF-V01 or ISD-100HF-V02 integrating sphere

The 100 cm diameter ISD-100HF-V01 integrating sphere makes it possible to measure the luminous flux, spectrum, color, and color rendering index of extra-large LED lamps with 2 pi and 4pi radiation characteristics inside the sphere. One half of the sphere can be opened in order to fix LED lamps onto the sample holder at the center of the sphere. The height of the sample holder can be adjusted. The ISD-100HF-V02 is offered as an alternative and has an additional measurement port with a 254 mm diameter for the measurement of 2pi lamps. This remains closed whenever it is not in use. Both variants are equipped with an auxiliary lamp. The BTS256-LED can still be used to measure single, onboard LEDs. A bayonet adapter enables connection of the device onto the ISD-100HF integrating sphere.

Determination of flicker properties and TLA

In addition to the investigation of light-metric quantities such as luminous flux, spectrum, color, etc., other properties of light sources play a significant role. In order to be able to offer light sources on the European market, an investigation of temporal intensity modulations such as light flicker and stroboscopic effects is necessary according to the Ecodesign Directive. This application field is summarized under the term "Temporal Light Artefacts (TLA)".

Gigahertz-Optik offers the integrating sphere model ISD-100HF-V08 as a variant. In addition to the spectroradiometer BTS256-LED Tester, this model offers the option of connecting an additional photodiode-based detector. It enables the measurement of flicker and TLA in conjunction with the PFL-200 measuring device.

In detail, the following measured quantities become available:

• Percent Flicker (IEEE Std 1789-2015, IES: RP-16-10, CIE:TN-006, CIE:TN-012)
• Flicker Index (IEEE Std 1789-2015, IES: RP-16-10, CIE:TN-006, CIE:TN-012)
• FFT Frequency component analysis
• P_st Short term flicker severity (CIE:TN-006, CIE:TN-012, IEC TR 61547)
• Stroboscopic Visibility Measure, SVM (CIE:TN-006, CIE:TN-012, IEC TR 63158)
• M_p ASSIST Flicker perception metric
• Joint Appendix JA10

Calibration

One essential quality feature of photometric devices is their precise and traceable calibration. The ISD-100-HF with the BTS256-LED is calibrated by Gigahertz-Optik’s calibration laboratory that is accredited by DAkkS (D-K-15047-01-00) for the spectral responsivity and spectral irradiance according to ISO/IEC 17025. Calibration for the luminous flux is performed using a BN-LHSF-104, which is placed at the sphere center. Spheres with an additional measurement port require additional calibration with a BN-LHSF-2P-20 calibration lamp, which has 2pi radiation characteristics in the integrating sphere. Every device comes with its respective calibration certificate.