GB-GD-360-RB40-2-BTS2048-VL

Measurement of the luminous intensity distribution

Luminous intensity distribution is used to specify the directional radiation characteristics of lamps. It is determined through numerous separate measurements of the luminous intensity. Every measurement detects the light emitted into the half space around the lamp under a different viewing angle. The measurement data are represented in polar plots and 3D graphs and output in standard formats e.g., IES, EULUMDAT, Excel, etc. This data can also be used to calculate the luminous flux.

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 with cosine corrected field of view for the measurement of spectral irradiance and spectral illuminance. This also makes it possible to combine the BTS2048-VL with goniometers for the measurement of luminous intensity distributions.  Its impressively wide dynamic range makes it ideal for the measurement of spot lamps that have a distinctive edge profile. 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.

Enhancement of the BTS2048-VL with the GB-GD-360-RB40-2 goniometer

The BTS2048-VL spectroradiometer can be combined with the GB-GD-360-RB40-2 goniometer in order to measure luminous intensity distribution. Unlike most conventional spectroradiometers , the BiTec sensor of the BTS2048-VL makes it possible to perform measurements using just an internal photometric photodiode and hence measurements are much fasterIf the spectrum, color, and color rendering index are needed, the CCD based spectrometer may also be employed. This flexibility provided by the BiTec technology makes it ideal for goniometric measurements (article on the BTS technology). The GB-GD-360-RB40-2 goniometer facilitates the alignment of the test lamp for measurements with two degrees of freedom. The rotation movements are controlled remotely using stepper motor drives. The turntable has an M4 hole pattern for universal attachment of test lamps. Four mini-sockets allow for four-terminal electrical connections. The turntable enables fine tuning with 5 mm stroke and a coarse tuning with 100 mm stroke for alignment of test lamps in the goniometric axis. A removable stop is integrated to aid the alignment of the test lamp in the goniometric axis. The distance between the device and the test lamp can be varied between 100 mm and 2000 mm. Short distances are chosen for measurement of single LEDs with low intensity. Longer distances are more suitable for measurement of extended LED arrays and LED lamps. The rail on the guide carriage is stiffened by means of a stable base.

Software

The S-BTS2048 user software supports operation of the goniometer and display of measurement values. It can be used to create measurement sequences as well as configure different settings. The measurement data can be exported to standard formats such as IES, EULUMDAT, ASCII, and Excel. Besides the display of the luminous intensity distribution in 3D and polar graphs, the software can also be used to calculate the luminous flux as well as display the spectrum, color values, etc.

 Calibration

One essential quality feature of photometric devices is their precise and traceable calibration. The BTS2048-VL is calibrated at Gigahertz-Optik’s DAkkS-accredited (D-K-15047-01-00) calibration laboratory for spectral responsivity and spectral irradiance in line with ISO/IEC 17025. Calibrations are also performed for irradiance. Every device is delivered with its respective calibration certificate.