ISD-15-BTS2048-VL

The BTS2048-VL light meter

The high-quality BTS2048-VL CCD based spectroradiometer is internationally recognized as a high-end product. It is one of the most compact spectroradiometers on the market which enables direct system integration in many applications without the need for expensive, and potentially measurement degrading, light guides. Among its characteristic features is its diffusor window which permits direct mounting onto integrating spheres (e.g. the ISD-15) for measurement of luminous flux. More detailed information about the BTS2048-VL can be found in the respective data sheets. The unit is also available in the BTS2048-VL-TEC thermoelectric cooled version.

Use of the BTS2048-VL for front-end and back-end LED binning

The BTS2048-VL is ideally suited for use in industrial LED binning. In particular, it can be used to perform time-synchronized, pulsed measurements of LEDs as stipulated by CIE S025 or DIN 5032-9. This is necessary when one wants to account for thermal effects in measurements. Furthermore, due to its fast electronics, the measurement of temporal light artefacts (TLA) is possible. The instantaneous, electronic zero setting of all pixels (electronic shutter) of the CCD sensor in conjunction with its trigger interface, results in perfect synchronization between the BTS2048-VL’s measurement and the LED current supply. The device also has an exceptionally wide dynamic range with a minimum integration time of just 2 µs. This, is 1000 times shorter than conventional devices (typically milliseconds), hereby makes it possible to achieve an OD3 factor. Additionally, the internal OD1 and OD2 filters increase the dynamic range up to 9 orders of magnitude and the fast Ethernet interface provides rapid data transfer. For users to integrate the device into their system, the BTS2048-VL is supplied with the powerful S-SDK-BTS2048 software development kit.

Enhancement of the BTS2048-VL to a 2Pi luminous intensity spectroradiometer

The BTS2048-VL can be combined directly with integrating spheres in order to measure luminous intensity. With its compact design, light weight, and no need of a connecting light guide, the integrating sphere and spectroradiometer form a monolithic module that can be conveniently integrated in complete test systems for front-end and back-end LED binning. It is supplied as a fully calibrated module. The module can be recalibrated as a single entity. Eliminating the need for connecting light guides enables convenient recalibration with low uncertainty The BN-LHSF-2P-20 2pi calibration lamp can be used to perform the recalibration directly in the test system using the supplied user software.

The modular integrating sphere concept from Gigahertz-Optik GmbH allow for customization and hence the best possible adaptation of the integrating sphere to the specific application.

The ISD-15-V01 integrating sphere for industrial LED binning

The ISD-15-V01 has many properties that make it perfect for luminous flux measurements in combination with the BTS2048-VL spectroradiometer. It has a 150 mm (6 inch) diameter and offers a good compromise in terms of 2pi acceptance and light throughput for high sensitivity. The 35 mm diameter measurement port has a knife edge for unrestricted light entry. A transparent dome behind the measurement port is integrated to protect the coating of the sphere from contamination in industrial environments. The sphere features an auxiliary lamp to compensate for the self-absorption effects. Illumination with the auxiliary lamp is done through a diffusor window.

Calibration

One essential quality feature of photometric devices is their precise and traceable calibration. The ISD-15-V01 -BTS2048-VL 2pi luminous flux spectroradiometer is calibrated at Gigahertz-Optik’s DAkkS-accredited (D-K-15047-01-00) calibration laboratory for the spectral responsivity and spectral irradiance in line with ISO/IEC 17025. The calibration is performed with a BN-LHSF-2P-20 calibration lamp that has 2pi radiation characteristics in the integrating sphere. Every device comes with its respective calibration certificate.

Software for system integration

Gigahertz-Optik offers the S-SDK-BTS2048 software development kit for integration of the ISD-15-BTS2048-VL 2pi luminous flux spectroradiometer with the system software of the user’s LED test systems.