BTS2048-VL ultra-fast BiTec sensor light meter for high-quality photometric, radiometric, spectral-radiometric and colorimetric measurements.

The BTS2048-VL is a high-quality light meter whose compact design and elaborate optical, electronic and mechanical interfaces make it ideal for integration in complex industrial and scientific measurement tasks.

BiTec light sensor for high-end light measurement 

One of the outstanding features of this exceptional light meter is its BiTec light sensor. This combines the special properties of a silicon photodiode with those of a back-thinned CCD diode array. Through bilateral correction of measurement signals from both sensors, the BiTec sensor ensures extremely precise photometric and spectral-radiometric measurement values over a large dynamic range.

High-quality back-thinned CCD detector 

The diode array comprising of 2048 pixels has a utilizable spectral responsivity range between 280 nm and 1050 nm. It has a 2 nm optical bandwidth and a pixel resolution of 0.4 nm/pixel. Due to the back-thinned technology, this CCD chip is substantially more sensitive as compared to conventional front-illuminated CCD chips.

Flash spectral radiometer for LED binning 

Another of its features is that the back-thinned CCD detector is equipped with an electronic shutter. This makes the measurement within a light flash possible. Together with the diverse trigger functions, integration times of between 2 µs and 4000 ms, the powerful micro-processor and the very fast LAN interface (7 ms for a complete data file), the BTS2048-VL qualifies for LED binning applications as well as for measurement of light flashes.

Precise spectral radiometry 

To facilitate optimum use of the CCD sensor‘s dynamic range, there is a remote controlled filter wheel (Open, Closed, OD1 and OD2) located in the optical beam path. This enables amplification of the dynamic range of the CCD sensor and offset compensation to additionally ensure precise measurement of light sources having varying intensities.

Diffuser window instead light guide 

As for the input optics, the BTS2048-VL has an incorporated diffuser window with a cosine corrected field of view. The fact that a light guide has not been used to this effect makes room for improved photosensitivity and calibration stability for reduced measurement uncertainty. The f2 adjustment of the cosine corrected field of view to less than 3% makes it possible to use the BTS2048-VL for direct light measurement in absolute photometric, colorimetric and radiometric measurands as well.

  • Illuminance (lx)
  • Luminous intensity (cd)
  • Color temperature
  • Color Rendering Index
  • Color coordinates
  • Irradiance (W/m²)
  • Spectral irradiance (W/m² nm)
  • Radiant intensity (W/sr)
  • Spectral radiant intensity (W/sr nm)

Luminous flux measurement 

In connection with integrating spheres, the BTS2048-VL is the optimal light meter for measurement of the luminous flux, spectral radiant flux and luminous color. The prefixed diffuser window can be positioned in the sphere such that an uninterrupted hemispherical field of view is created. This thereby enables the sphere photometer to fulfill one of the essential requirements for the LM79 as well as meet other standards. Gigahertz-Optik manufactures a wide range of integrating spheres as well as the necessary accessories e.g. calibration standards.

Measurement of the luminous intensity distribution 

Goniometers are used to measure the luminous intensity distribution of lamps and other luminaires. For these type of applications, the BTS2048-VL offers ideal conditions to shorten the entire measurement time of the goniometric measurement:

  • Fast, photometric matched photodiode for short measurement times over a large dynamic range. Photodiode with active correction of the spectral mismatch through spectral measurement values
  • Fast, spectral measurements through the optimized optics and the high-quality diode array
  • Synchronized measurements through the diode array with electronic aperture and trigger functions
  • Ethernet and USB2.0 interfaces for fast data exchange (30ms for 2048 float values via ethernet)

Gigahertz-Optik manufactures goniometers in different designs.

Ultra fast interfaces 

The BTS2048-VL is controlled via a USB 2.0 or ethernet. With regards to the communication speed, ethernet port is superior to the USB 2.0 interface. Furthermore, the amount of data to be sent is thereby limited so that data preparation occurs in the BTS2048-VL. For this purpose, an independent, high-performance microprocessor is incorporated.

User software with flexible desktop structure 

Among the BTS2048-VL 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, photometric, colorimetric, Ra to R15 color rendering index, spectral and other measurands.
  • Measurement protocol of the selected measurement parameters.
  • CIE 1931 chromaticity diagram. Zoom function.
  • CIE 1976 chromaticity diagram. Zoom function.
  • Spectrum. Zoom function.
  • Data logger. Zoom function.
  • etc.

Traceable calibration 

Calibration of the BTS2048-VL, including its accessories, is performed by Gigahertz-Optik calibration laboratory for optical measurands with reference to national and international calibration standards. 

 

The BTS2048-VL can directly plugged on a integrating sphere

Electronic Shutter reduces the measurement time

Ethernet interface reduces the datatransfer time

S-BTS2048 User software interface

Graphical view of the spectrum

CIE 1976 Chromaticity diagram

CRI Bar Plot

General
Short description
Main features
Range of measurement
Typical applications
Calibration
Product
Application

Lightmeter for Illuminance, spectral Irradiance and light color

Measurands

Spectral irradiance (W/(m² nm)), illuminance (lx), dominant wavelength, peak wavelength, center wavelength, centroid wavelength, x, y, u´, v´, X,Y,Z, delta uv, color temperature, color rendering index (CRI) Ra, R1-R15, Option integrating sphere: in addition spectral flux (W/nm) and luminous flux (lm) Option goniometer: in addition radiant intensity and luminous intensity distribution

Light Sensor

Accuracy class B according to DIN 5032 and CIE No. 69
Accuracy class A for f1`, u, f3 and f4 according to DIN 5032 and CIE No. 69

Input optics

Diffusor, cosine corrected field of view (f2 ≤ 3 %)

Filter wheel

4 positions (open, closed, OD1, OD2). Use for remote dark current measurement and dynamic range extension.

BiTec

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 Detector
Integration time

2 μs - 4 s        *1

Spectral range

(280 -1050) nm

Optical bandwidth

2 nm

Pixel resolution

~0.4 nm/Pixel

Number of pixels

2048

Chip

Highly sensitive back-thinned CCD chip

ADC

16bit (25 ns instruction cycle time)

Peak wavelength

±0.2 nm

Dominant wavelength

±0.5 nm           *2

Uncertainty Δx und Δy

±0.0015 (Standard illuminant A)
±0.0020 (common LED)

Repeatability Δx and Δy

±0.0001

ΔCCT

Standard illuminant A 30K; LED up to +/- 1.5% depending of the LED spectrum

Band-pass correction

mathematical online band-pass correction is supported

Linearity

completely linearized chip >99.6%

Stray light

2E-4           *3

Base line noise

5 cts     *4

S/N

5000        *5

Dynamic range

>9 Magnitudes

Calibration

Spectral irradiance

(350 - 399) nm: OD0: +/- 7 % OD1: +/- 8 % OD2: +/- 9 %
(400 - 800) nm: OD0: +/- 4 % OD1: +/- 4 % OD2: +/- 4 %
(801 - 1000) nm: OD0: +/- 6 % OD1: +/- 6 % OD2: +/- 6 %
(1001 - 1050) nm: OD0: +/- 7 % OD1: +/- 8 % OD2: +/- 9 %

Spectral irradiance responsivity (350 - 1050) nm

Responsivity range spectral irradiance

(1E-5 - 1E5) W/(m²nm)           *6*7

CRI (color rendering index)

Ra and R1 to R15

typ. measurement time

10lx    2,5s      *10
100lx    250ms      *10
1000lx    25ms      *10

Integral Detector
Filter

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

Measurement time

(0.1 - 6000) ms

Measurement range

seven (7) measurement ranges with transcendent offset correction

Measurement range

Max measureable illuminance value 3E8lx *7
Noise equivalent illuminance value 1E-1lx

Calibration

Illuminance +/- 2,2 %

f1'

≤6%

≤3% (f1' a*(sz(λ)) respectively F*(sz(λ)) corrected)

Graphs
Spectral responsivity

spectral responsivity

f2 uncertainty

f2 uncertainty BTS2048

Miscellaneous
Processors

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

Interface

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

Data transfer

Standard for 2048 float array values via ethernet 7ms, via USB 2.0 140 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

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

Software

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 700 mA
With USB bus (500mA) *8

Dimensions

103 mm x 107 mm x 52 mm (Length x Width x Height)

Weight

500g

Mount

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

Info

*1 It is recommended to perform a new dark signal measurement for every change in the integration time
*2 typical value, the uncertainty of the dominant wavelength depends on the spectral distribution of the LED
*3 typical value, measured 100nm left of the peak of a cold white broadband LED
*4 *5 typical value measured without averaging for a 4ms measurement time and full scale control of the array. Averaging results in quadratic rise of the S/N
i.e. quadratic fall of the base noise e.g. averaging to a factor 100 improves the S/N by a factor 10
*6 Minimum 500/1 S/N. Maximum at full scale control.
*7 Irradiation only allowed for a short time so as to avoid thermal damage
*8 during USB connection, not all functions are available due to the limited current supply e.g. no Ethernet
*9 Device required for temperature stabilization in approx. 25min. In measurement is performed in the warm-up phase, or if measurements are performed
under varying temperatures, dark signal measurement is required for each measurement
*10 measurement of a white LED and 20000 counts (signal-dark) saturation

Option: 150mm Integrating Sphere (UMBB-150)
spectral radiant flux responsivity range (spectral measurement)

(5E-8 - 5E2) W/nm

Luminous flux measurement range (integral measurement)

(3E-5 - 1E5) lm

Sphere diameter

150 mm

typ. measurement time

measurement with 20000cts:

1lm 80ms
10lm 8ms
100lm 800μs

 

optimized measurement time with 5000cts and noise reduction:

10lm 2ms

Calibration

Luminous  flux: ± 4 %

Spectral radiant power:

(350 - 399) nm: OD0: +/- 8 % OD1: +/- 10 % OD2: +/- 10 %
(400 - 800) nm: OD0: +/- 4,5 % OD1: +/- 4,5 % OD2: +/- 4,5 %
(801 - 1000) nm: OD0: +/- 6,5 % OD1: +/- 6,5 % OD2: +/- 6,5 %
(1001 - 1050) nm: OD0: +/- 8 % OD1: +/- 10 % OD2: +/- 10 %

Spectral radiant power responsivity (350 - 1050) nm

Option: 210mm Integrating Sphere (UMBB-210)
spectral radiant flux responsivity range (spectral measurement)

(1E-7 - 1E3) W/nm

Luminous flux measurement range (integral measurement)

(7E-5 - 2E5) lm

Sphere diameter

210 mm

typ. measurement time

measurement with 20000cts:

1lm 160ms
10lm 16ms
100lm 1600μs

 

optimized measurement time with 5000cts and noise reduction:

10lm 4ms

Calibration

Luminous  flux: ± 4 %

Spectral radiant power:

(350 - 399) nm: OD0: +/- 8 % OD1: +/- 10 % OD2: +/- 10 %
(400 - 800) nm: OD0: +/- 4,5 % OD1: +/- 4,5 % OD2: +/- 4,5 %
(801 - 1000) nm: OD0: +/- 6,5 % OD1: +/- 6,5 % OD2: +/- 6,5 %
(1001 - 1050) nm: OD0: +/- 8 % OD1: +/- 10 % OD2: +/- 10 %

Spectral radiant power responsivity (350 - 1050) nm

Option: 1000mm Integrating Sphere (UMTB-1000-HFT)
spectral radiant flux responsivity range (spectral measurement)

(2E-6 - 2E4) W/nm

Luminous flux measurement range (integral measurement)

(1E-3 - 4E6) lm

Sphere diameter

1000 mm

typ. measurement time

measurement with 20000cts:

10lm 450ms
100lm 45ms
1000lm 4,5s

 

optimized measurement time with 5000cts and noise reduction:

10lm 112ms

Calibration

Luminous  flux: ± 4 %

Spectral radiant power:

(350 - 399) nm: OD0: +/- 8 % OD1: +/- 11 % OD2: +/- 11 %
(400 - 800) nm: OD0: +/- 4,5 % OD1: +/- 5 % OD2: +/- 5 %
(801 - 1000) nm: OD0: +/- 6,5 % OD1: +/- 7 % OD2: +/- 7 %
(1001 - 1050) nm: OD0: +/- 8 % OD1: +/- 11 % OD2: +/- 11 %

Spectral radiant power responsivity (350 - 1050) nm

Option: Goniometer (GB-GD-360-RB40)
spectral radiant intensity responsivity range (spectral measurement)

(1E-5 - 1E5) W/(sr nm)  ; by 1m measurement distance

Luminous intensity measurement range (integral measurement)

(1E-1 - 3E8) cd ; by 1m measurement distance

Calibration

Luminous intensity: ± 4 %

Spectral Radiant intensity:

(350 - 399) nm: OD0: +/- 7 % OD1: +/- 8 % OD2: +/- 9 %
(400 - 800) nm: OD0: +/- 4 % OD1: +/- 4 % OD2: +/- 4 %
(801 - 1000) nm: OD0: +/- 6 % OD1: +/- 6 % OD2: +/- 6 %
(1001 - 1050) nm: OD0: +/- 7 % OD1: +/- 8 % OD2: +/- 9 %

Spectral radiant intensity responsivity (350 - 1050) nm

Option: ILED-B (CP-ILED-B-IS-1.0-HL)
spectral radiant intensity (ILED-B) responsivity range (spectral measurement)

(5E-7 - 5E3) W/nm

measurement range ILED-B (integral measurement)

(3E-4 - 1E6) cd

Calibration

Luminous intensity ILED-B: ± 4 %

Spectral Radiant intensity ILED-B:

(350 - 399) nm: OD0: +/- 7 % OD1: +/- 8 % OD2: +/- 9 %
(400 - 800) nm: OD0: +/- 4 % OD1: +/- 4 % OD2: +/- 4 %
(801 - 1000) nm: OD0: +/- 6 % OD1: +/- 6 % OD2: +/- 6 %
(1001 - 1050) nm: OD0: +/- 7 % OD1: +/- 8 % OD2: +/- 9 %

Spectral radiant intensity responsivity (350 - 1050) nm

Type Description File-Type Download
Datasheet BTS2048-VL PDF
Drawing Dimensions BTS2048-VL PDF
Produktname Product Image Description Show product
GB-GD-360-RB40 Goniometer for the measurement of 2π sources.

Features: Measurement of the luminous and radiant intensity distribution as well as luminous flux and radiant power from compact spot lamps and light-emitting diodes. Measurement distance 100 mm to 2000 mm. Remote control. Optional Lightmeters, user software, etc.
UMTB-1000-HFT Sphere for the luminous flux measurement of 2π and 4π light fixtures inside a sphere.

Features: Turnable Integrating sphere with a 1000 mm diameter, extra measurement ports for 2π luminaires with diameters of up to 254mm and auxiliary lamp.
CP-ILED-B-IS-1.0-HL Measurement Adapter for ILED-B

Features: High uniformity, CIE 127, UMPA-1.0-HL mount.
ISD-100HF-V06-BTS2048-VL System for the luminous flux and light color measurement of individual 2π and 4π light light sources.

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.
S-BTS2048 Application software for BTS2048 variants
S-SDK-BTS2048 Software Development Kit for BTS2048 variants
Article-Nr Modell Description Notice
Product
15298281 BTS2048-VL

Measuring device, hard cover box, users guide, software CD, calibration certificate.

Calibration
15300499 K-BTS2048-VL-I

Recalibration of the BTS2048-VL with calibration certificate

Software
15298470 S-SDK-BTS2048

Software development kit, software CD with users guide.

15298474 S-BTS2048

User software for BTS2048 and variants.


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