This Product is discontinued, please contact us if you are still interested. An alternative is e.g:

BTS2048-IR spectroradiometer with thermoelectrically cooled detector

The BTS2048-IR incorporates thermoelectric cooling of its InGaAs array detector and also a cooled InGaAs Diode for the BTS technology. The device meets all the requirements of a high-end diode array spectroradiometer and is favourably priced despite its cutting-edge design. Thermoelectric cooling of the array detector minimizes the dark noise signal.

Innovative detector technology

In order to make use of the advantages of an InGaAs chip that is less noisy compared to an extended InGaAs chip in the possible spectral ranges, a detector chip with both technologies is used. This matches the spectral ranges optimally and thus allows the best electro-optical properties. Other features such as an electronic shutter, OD filter and the proven BTS technology find their place as usual.

 Features on a glance

  • Spectral range from 950 nm to 2150 nm
  • BTS technology (integrated additional diode)
  • Electronic shutter and filter wheel with four positions (open, dark, OD1 and OD2)
  • Convincing optical properties 
  • Compact dimensions
  • Fast data transmission due to Ethernet and USB interface
  • I/O connector
  • Traceable calibration

User software and developer software

The standard S-BTS2048 user software has a customizable user interface and a large number of display and function modules that can be activated when configuring the BTS2048-IR with the respective accessory components from Gigahertz-Optik GmbH. The S-SDK-BTS2048 developer software is offered for the integration of the BTS2048-IR in custom software.


One essential quality feature of photometric devices is their precise and traceable calibration. The BTS2048-IR is calibrated by Gigahertz-Optik’s calibration laboratory that was accredited by DAkkS (D-K-15047-01-00) for the spectral responsivity and spectral irradiance according to ISO/IEC 17025. The calibration also included the corresponding accessory components. Every device is delivered with its respective calibration certificate.

The BTS2048-IR spectroradiometer with thermoelectrically cooled array detector

Cosine corrected diffuser and several trigger and I/O possibilities

S-BTS2048 User software interface
Short description

TE cooled spectroradiometer with a wide dynamic range for CW and short-term measurement of the irradiance, spectrum, and peak wavelength. Accessories for other parameters. 

Main features

Compact device. BiTec detector with TE cooled detector (512 pixels, 9 nm optical resolution, electronic shutter), and additional InGaAs diode. Optical bandwidth correction (CIE214). Filter wheel with shutter and OD-Filter. Input lens with diffusor window. Cosine field of view.

Measurement range

Spectral: 2E-4 W/(m²nm) to 1E4 W/(m²nm) @1600 nm. Responsivity from 950 nm to 2150 nm.

Integral: 2E1 W/m² to 6E7 W/m², responsivity from 1050 nm to 2100 nm.

typical applications

Diode array spectroradiometer for R&D applications and for the integration in testing systems.


Factory calibration. Traceable to international calibration standards

Measured Quantity

Spectral irradiance (W/(m² nm)), irradiance (W/m²), spectral radiant intensity (W/(sr nm)), radiant Intensity (W/sr), peak wavelength, center wavelength, centroid wavelength, etc.. Option integrating sphere: in addition spectral flux (W/nm). Option goniometer: in addition radiant intensity (W/sr)

Input optics

Diffusor, cosine corrected field of view

Filter wheel

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 an online correction of the spectral mismatch of the diode through a*(sz(λ)) respectively F*(sz(λ)).

Spectral Detector
Calibration uncertainty

Spectral irradiance

wavelength range / nm

calibration uncertainty (k=2) / %

(950 to 1039) nm


(1040 to 1549) nm


(1550 to 1949) nm (Sensor part 1)


(1550 to 1949) nm (Sensor part 2)


(1950 to 2049) nm


(2050 to 2150) nm


Spectral irradiance responsivity (950 - 2150) nm

Integration Time

10 µs - 20 s    *11

spectral range

(950 -2150) nm

Optical Bandwidth

9 nm

Pixel resolution

~2.3 nm/Pixel

Number of pixels



cooled highly sensitive InGaAs chip with second order filter



Peak wavelength

± 1 nm

Band-pass correction

mathematical online band-pass correction is supported


completely linearized chip >99% *10

Base line noise

7 cts   *1


5000   *2

dynamic range

8 Magnitudes

spectral irradiance responsivity range

spectral responsivity BTS2048 IR

Integral Detector

Spectral responsivity with radiometric matching. Online correction of the radiometric matching through spectral measurement data (spectral missmatch factor correction).

Measurement range

Nine (9) measurement ranges with offset correction

Measurement range

min. measurable irradiance (diode): 15 W/m²

max. measurable irradiance (diode): 6E7 W/m²

responsivity range: (1050 - 2100) nm


32bit for device control,16bit for detector array control, 8bit for photodiode control


USB V2.0, Ethernet (LAN UDP protocol), RS232, RS485

Data transfer

Standard for 512 float array values via ethernet 5 ms

Input Interfaces

2x (0 - 25) VDC, 1x optocoupler isolated 5 V / 5 mA

Output Interfaces

2x open collector, max. 25 V, max. 500 mA


Trigger input incorporated (different options, rising/falling edge, delayed, etc.)


User software S-BTS2048
Optional software development kit S-SDK-BTS2048 for user software set-ups based on .dll‘s in C, C++,C# or in LabView.

Power Supply

With power supply: DC Input 5V (±10 %) at 3000 mA

temperature range

Temperature stabilization chip: ≤ ± 0.25 °C


135 mm x 107 mm x 90 mm (Length x Width x Height)




Tripod and M6 screw threads

Front adapter UMPA-1.0-HL for use with integrating sphere port-frame UMPF-1.0-HL

temperature range

Storage: (-10 to 50) °C

Operation: (10 to 30) °C           *9


* 1 typical value measured without averaging with an integration time of 1ms (standard deviation). With averaging the base line noise reduces.

* 2 typical value measured without averaging with a measuring time of 1ms and full saturation of the detector. With averaging the SNR increases.

*9 The device takes about 25 minutes to stabilize in temperature. If measurements are taken in the warm-up phase or at non-constant temperatures, a new dark measurement is required for each measurement.

*10 The chip is basend on two different materials depending on the spectral range. Upper half (extendend InGaAs) may show a higher uncertainty at longer integration times.

*11 At longer integration times the possible saturation for the extendend InGaAs range may be limited by ambient temperature

Type Description File-Type Download
Datasheet BTS2048-IR PDF
Dimensions BTS2048-IR technical drawing PDF
Produktname Product Image Description Show product
ISD-100HF-BTS2048-VL System for the luminous flux and light color measurement of individual 2π and 4π light light sources including the measurement of temporal light artefacts (TLA) and flicker according to IES and CIE

Features: Integrating sphere with 100cm diameter, auxiliary lamp and a hemispherical shell for opening and closing, compact spectral light meter with Bi-Tec sensor for acurate measurement of the luminous flux, spectral radiant power, CCT, CRI, chromaticity coordinates, etc.
ISD-15-BTS2048-VL Compact integrating sphere spectroradiometer as monolithic module for LED test system Integration in CW and pulse measurement mode.

Features: Integrating sphere with 15 cm Diameter, auxiliary lamp, high-end CCD-sensor spectralradiometer with Bi-Tec detector for fast and acurate measurement of the luminous flux, spectral radiant power, CCT, CRI,
ISD-25-BTS2048-VL System for the luminous flux and light color measurement of individual 2π LED lamps up to 76.2 mm.

Features: Integrating sphere with 25cm diameter and auxiliary lamp, CCD-sensor spectralradiometer for acurate measurement of the luminous flux, spectral radiant power, CCT, CRI
Article-Nr Modell Description Request / Compare
15308288 BTS2048-IR

Measuring device, hard cover box, users guide, S-BTS2048 software, calibration certificate.

15298470 S-SDK-BTS2048

Software development kit, software CD with users guide.

15312474 BTS2048-Z03

Trigger cable. For use with LPS-20 power supply.

Product tags

Similar products