Application of JETI Spectroradiometers specbos and spectraval

Light Measurement in Laboratory 

The following four basic quantities exist in light measurement:









Simplified definition


Used for characterization of


   Luminous flux







Halogen lamps, LEDs ("optical power" into all directions)


   Luminous intensity




(basic unit)




Point like sources as LED and lamps with reflector










Homogenious sources as monitors and video walls










Light intensity » in a certain plane

For an extended scheme see Application Note 20.


The spectroradiometer specbos includes different models which allow to measure all these four quantities based on the spectral resolving technique. This universal system covers all spot measurement applications in the lab and is therefore best suited for a general use.
Besides the photometric data and the spectrum also the radiometric and colorimetric data are obtained.
The basic unit specbos 1211 allows to measure in luminance and in illuminance mode and ordered with various accessories. specbos 1311 adds luminous flux and specbos 1411 luminous intensity.
The new spectroradiometers spectraval measure the spectral radiance and in addition to the radiometric and photometric values the colorimetric values x, y, color temperature, color purity, dominant wavelength and the color rendering indices are determinable.


specbos 1211 bt



specbos1311 300




specbos 1211-BT
spectraval 1501
specbos 1311
specbos 1411


Furthermore the luminous intensity of a source can be measured using the illuminance mode of specbos 1211 (see application: Radiant intensity calculation using irradiance measurement).