Traditional lux meters are increasingly being replaced by spectral light meters such as the MSC15. However, the lighting industry also needs high accuracy spectral light meters that can handle more complex measurements. These include measurement of pulse width modulated light and the ability to measure both internal and external illumination, determination of thermal transient behavior of lamps, and so on. The primary criterion that such meters must always meet is the quality of their photometric features. Additional electronic features may improve usability and display quality, but they cannot compensate for substandard measurement results.
BTS256-E – compact, handheld meter for complex measurements
With the BTS256-E, Gigahertz-Optik GmbH offers a light meter that is perfectly suited for complex measurements in the lighting industry. Its technical concept guarantees high-quality measurement of illuminance, spectrum, color, and color rendering index (video). The heart of this compact device is its BiTec sensor which combines two different sensor technologies, i.e. a Si photodiode with a V-lambda filter and a spectroradiometer unit that is based on a CMOS diode array.
The Si photodiode offers extraordinary properties in terms of dynamic range, linearity, and speed of measurements. Combining the two allows mutual correction (BTS technology) in order to ensure even higher accuracy. Another unique feature is its ability to perform time-synchronized measurements of pulse-width modulated light and hence guarantee correct illuminance measurements in PWM lighting systems.
The spectrometer ensures high accuracy in luminous spectral measurements and has a 10 nm optical bandwidth in the spectral range between 380 nm and 750 nm. An optical bandwidth correction function according to CIE 214 is incorporated, further improving the quality of values (e.g. peak wavelength) that are calculated based on the spectral measurement data. Given its compact size, the unit exhibits outstanding scattered light performance which provides extraordinary precision even in complex measurements. Another key feature of this compact light meter is the remote-controlled shutter for automatic dark signal correction.
A significant consideration for precise illuminance measurements of lighting systems is the field of view of the measurement optics. Correct illuminance measurements are only possible with a precise cosine field of view function for the different angles of incidence.
The device is extremely easy to use thanks to the intuitive menu and the supplied software with which it can be controlled remotely. The device housing is watertight for outdoor light measurements.
Calibration of the BTS256-E
One essential quality feature of photometric devices is their precise and traceable calibration. The BTS256-E is calibrated by Gigahertz-Optik’s calibration laboratory that is 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.
Options for the BTS256-E light meter
- Software development kit for integration of the device in the user’s own software
BTS256-E for complex measurements in lighting technology
1) BTS256-E 2) Precision cosine diffuser 3) BiTec sensor with Si photodiode, CMOS diode array spectrometer and shutter 4) Microprocessor 5) Display 6) Control Buttons 7) USB 2.0 interface 8) Light incident
Precise cosine-corrected field of view function
Robust aluminum housing with tripod mount
Standard display for the illuminance and spectrum
Ratio of the scotopic and photopic illuminance with the EVE factor as per IES TM-24-13
The measurement parameters protocol is saved together with a measurement data file
Standard display with illuminance, x,y color coordinates, color temperature and emission spectrum of an energy saving lamp
S-BTS256 user software with modular setup desktop
The graphical display module can be zoomed
Spectroradiometer for the illuminance (photopic, scotopic, melanopic), spectrum, light color, and color rendering index.
Mobile measurement device, BiTec sensor with a V-Lambda photodiode and low stray light CMOS spectroradiometer with a 10 nm optical bandwidth and additional optical bandwidth correction (CIE214), remote-controlled Offset shutter, precise cosine-corrected field of view, data logger, automatic PWM synchronization.
|Range of measurement||
3 lx to 199,000 lx, 380 nm to 750 nm.
Precise spectral light meter for the lighting industry.
Factory calibration, traceable to international Standards.
class B DIN 5032 part 7 or AA according to JIS C 1609-1:2006
Bi-Technology sensor with a photometric broadband detector and a array spectrometer. Integrated aperture for automatic dark signal adjustment.
Diffuser window with 20mm diameter, cosine corrected field of view, f2 ≤ 3 %
(380 - 750) nm
(5.2 - 30000) ms
Automatic aperture for dark signal measurements with the same integration time as that of light measurements. Aperture delay = 100ms.
|Typ. Measurement Time||
199,999 lx ≤ 5ms (white light)
100 lx ≤ 1s (white light)
|Color measurement range spectral||
(1- 199,999) lx
Scotopic measurement range spectral (1 - 199,999) lx
|Δx, Δy reproducibility||
+/- 0.0001 (Standard illuminant type A)
+/- 0.0002 (LED)
|Δx, Δy uncertainty||
+/- 0.002 (Standard illuminant type A)
+/- 0.005 (typ. LED)
|CCT Measurement range||
(1700 - 17000) K
+/- 50K (standard illuminant type A)
+/- 4% (depending on the LED spectrum)
|CRI (color rendering index)||
Ra and R1 to R15
6E-4 (Blue LED)
6E-4 (Green LED)
6E-4 (Red LED)
1E-3 (White LED)
Spectral irradiance responsivity (380 - 750) nm
Spectral responsivity with fine CIE photometric matching. Online correction of the photometric matching through spectral measurement data (spectral missmatch factor correction)
≤3% (f1' a*(sz(λ)) respectively F*(sz(λ)) corrected by spectral data, done automatically by BTS technology)
|Max. measurable illuminance||
|Noise equivalent illuminance||
(0.1 - 6000) ms
|spectral irradiance responsivity|
16Bit, 25ns instruction cycle time
5VDC, 450mA per USB
USB 2.0 (Type B USB-Port)
Option WiFi: WiFi 2,4 GHz (external antenna, range > 100m)
Operation: -10°C bis +30°C
Storage: -10°C to +50°C
159mm x 85mm x 45mm (Length x Width x Height)
333mm x 280mm x 70mm
|Produktname||Product Image||Description||Show product|
|S-SDK-BTS256||Software Development Kit for BTS256 variants.|