BTS2048-VL-TEC-WP BiTec sensor spectroradiometer for high-quality outdoor VIS measurements
The BTS2048-VL-TEC-WP is a high-quality spectralradiometer whose compact design and elaborate optical, electronic and mechanical interfaces make it ideal for high precision outdoor VIS measurements. Due to its spectrometer design and optional stray light reduction by the well know Zong or Nevas matrix methods it is able to measure solar radiation with a good straylight reduction performance. With the included S-BTS2048 application software precise measurements and data analysis can be intuitive performed. In addition for the UV spectral range with the complementary BTS2048-UV-S-WP a high resolution and even better device in terms of stray light reduction is available.
BiTec sensor for high-end light measurement
One of the outstanding features of this exceptional spectroradiometer is its BiTec sensor. This combines the special properties of a photodiode with those of a back-thinned CCD diode array. Through bilateral correction of measurement signals from both sensors, the BiTec sensor ensures precise radiometric and spectral-radiometric measurement values over a large dynamic range (see technical article BTS Technologie).
Spectrometer based on a high-quality back-thinned CCD detector
The spectrometer unit is based on a diode array with a utilizable spectral responsivity range between 190 nm and 430 nm. It has a 0.7 nm optical bandwidth and a pixel resolution of 0.13 nm/pixel. Due to the back-thinned technology, this CCD chip is substantially more sensitive as compared to conventional front-illuminated CCD chips. Furthermore the CCD is one stage cooled (1TEC) to reduce the dark current and increased thereby the SNR.
Precise spectral radiometry (high dynamic and low straylight)
To facilitate optimum use of the CCD sensor‘s dynamic range and to overcome the problems of most array spectoradiometers in the UV range, the option to characterize and apply the Zong or Nevas straylight reduction methods is possible. For a high dynamic range a remote controlled filter wheel (Open, Closed, OD1 and OD2) is located in the optical beam path, this additional to the high dynamic of the integration times (2 µs to 60 s).
WP means weather proofed
The housing of the BTS2048-VL-TEC-WP is designed for outdoor measurements. The cooled backthinned CCD and the spectrometer unit are temperature controlled in a second housing. In this housing humidity is removed by a exchangeable cartridge. To avoid dust, rain or snow on the entrance optics the quartz dome is blow-dried by warm air.
Diffuser window directly connected instead of light guide
As for the input optics, the BTS2048-VL-TEC-WP has an incorporated diffuser window with a cosine corrected field of view. The fact that a light guide has not been used improves sensitivity and calibration stability which is an large advantage for outdoor use. Especially in terms of size of the device. The f2 adjustment of the cosine corrected field of view to less than 3% makes it possible to use the BTS2048-VL-TEC-WP for direct measurement in absolute radiometric measurands
- Irradiance (W/m²)
- Spectral irradiance (W/(m² nm))
State of the art interface
The BTS2048-VL-TEC-WP is controlled via a USB 2.0 or Ethernet interface. With regards to the communication speed and cable length the Ethernet port is superior to the USB2.0 interface. Furthermore, the data preparation occurs in the BTS2048-VL-TEC-WP to optimize the data-transfer speed. For this purpose, an independent, high-performance microprocessor is incorporated. Data and power interface are of course weatherproof designed as well.
User software with flexible desktop structure
Among the BTS2048-VL-TEC-WP delivery contents is the S-BTS2048 user software. One of the characteristic features it has to offer is the flexible desktop that can be individually configured by the user. This entails a potpourri from which the user can choose graphical and numerical display windows:
- Freely definable numerical displays in decimal or scientific representation. Zoom function.
- Numerical display fields for radiometric, spectral and other measurands.
- Measurement protocol of the selected measurement parameters.
- Spectrum. Zoom function.
- Data logger. Zoom function.
Calibration of the BTS2048-VL-TEC-WP, including its accessories, is performed by Gigahertz-Optik calibration laboratory for optical measurands with reference to national and international calibration standards. Due to the small dimensions of the device it can be shipped easily for re-calibration purposes.
Entrance optic is blow-dried by warm air to prevent dirt, rain or snow
Side View of the BTS2048-VL-TEC-WP
S-BTS2048 User software interface
Graphical view of the spectrum
The WP version in a winter measurement campaign
High speed TE cooled CCD spectroradiometer with a wide dynamic range for CW and pulsed measurements of irradiance/illuminance, specturm in the VIS region for outdoor measurements.
Compact device. BiTec detector with back-thinned TE cooled CCD (2048 pixels, 2 nm optical resolution, electronic shutter) and Si-photodiode with V(lambda) filter. Optical bandwidth correction (CIE214). Filter wheel with shutter and attenuation filters. Input lens with a diffusor window that has a cosine field of view. Housing for outdoor use.
|Range of measurement||
Spectral: 0.5 lx to 1,000,000 lx 280 nm to 1050 nm.
Integral: 0.1 lx Noise signal up to 3E8 lx, photometric 360 nm to 830 nm
CCD spectroradiometer for scientific measurements, solar cells, outdoor measurements, development tasks.
Factory calibration. Traceable to international calibration standards
Spectral irradiance (W/(m² nm)), illuminance (lx), peak wavelength, calculated quantities of the spectral power distribution, etc.
Accuracy class B according to DIN 5032 and CIE No. 69
Diffusor, cosine corrected field of view (f2 ≤ 3 %)
4 positions (open, closed, OD1, OD2). Use for remote dark current measurement and dynamic range extension.
Parallel measurement with diode and array is possible, thereby linearity correction of the array through the diode and online correction of the spectral mismatch of the diode through a*(sz(λ)) respectively F*(sz(λ)).
Spectral irradiance responsivity (350 - 1050) nm
2 μs - 60 s *1
(280 -1050) nm
|Number of pixels||
One stage cooled highly sensitive back-thinned CCD chip
16bit (25 ns instruction cycle time)
± 0.2 nm
± 0.5 nm *2
|Uncertainty Δx und Δy||
± 0.0015 (Standard illuminant A)
|Repeatability Δx and Δy||
Standard illuminant A 30K; LED up to +/- 1.5 % depending of the LED spectrum
mathematical online band-pass correction is supported
completely linearized chip >99.6%
|Base line noise||
5 cts *4
|Responsivity range spectral irradiance||
(1E-6 - 1E5) W/(m²nm) *6*7
|CRI (color rendering index)||
Ra and R1 to R15
|typ. measurement time||
10 lx 2,5 s *10
Spectral responsivity with fine CIE photometric matching. Online correction of the photometric matching through spectral measurement data (spectral missmatch factor correction).
(0.1 - 6000) ms
seven (7) measurement ranges with transcendent offset correction
Max measureable illuminance value 3E8lx *7
Illuminance +/- 2,2 %
≤ 6 % (uncorrected)
≤ 3 % (f1' a*(sz(λ)) respectively F*(sz(λ)) corrected by spectral data, done automatically by BTS technology)
32bit for device control,16bit for CCD array control, 8bit for photodiode control
USB V2.0, Ethernet (LAN UDP protocol), RS232, RS485
Standard for 2048 float array values via ethernet 7ms, via USB 2.0 140 ms
2x (0 - 25) VDC, 1x optocoupler isolated 5 V / 5 mA
2x open collector, max. 25 V, max. 500 mA
Trigger input incorporated (different options, rising/falling edge, delayed, etc.)
User software S-BTS2048
With power supply: DC Input 5V (±10 %) at 700 mA
diameter: 160 mm
height: 222 mm
Tripod and M6 screw threads
Front adapter UMPA-1.0-HL for use with integrating sphere port-frame UMPF-1.0-HL
Storage: (-10 to 50) °C
Operation: (-25 to 50) °C *9
inside WP housing (electronics): ≤ ± 1 °C
CCD Chip: ≤ ± 0.25 °C
*1 It is recommended to perform a new dark signal measurement for every change in the integration time
|Produktname||Product Image||Description||Show product|
|S-BTS2048||Application software for BTS2048 variants.|
|S-SDK-BTS2048||Software Development Kit for BTS2048 variants.|
|BTS2048-UV-S-WP||Bi-technology sensor light meter for high quality solar UV measurements.
Features: Weatherproofed, high stray light reduction (comparable double monochromator), high spectral resolution, short measurement time, entrance optic with diffusor for irradiance and spectral irradiance, etc.