PHOTOMETRY PRINCIPLE – Type C goniometers

Lighting fixtures for professional use need to be characterized. The basic input for all lighting design is a 3D-file that quantifies the entire light emission in all directions (photometry), i.e. the total amount of light and possibly also the color properties (spectral distribution, CCT, CRI, etc.) of a light source.

For these measurements you need a mechanical arrangement that allows you to measure all the way around the light source: A goniometer. In practice, it is necessary to select a limited number of measurement angles (gamma, γ) distributed in a set of measurement planes (C-planes).

In photometry systems with Viso technology, light sources are mounted on the goniometer with the main light output direction pointed horizontally toward the sensor. For most light sources this means that the normally vertical axis will be turned horizontally. Nevertheless, measurements can be performed to comply with the CIE S 025 standard.

FAST SPECTROMETER SENSOR

The heart of every Viso measurement system is the fast spectrometer sensor. With a spectrometer instead of a photometer the system captures light spectra and not just light quantities. This unique feature enables the system to measure much more than lumen packages and light distributions: All color data (e.g. CRI, CCT, TM30 etc.) and even color over angle. Hence, a Viso goniospectrometer will make an integrating sphere redundant. Read more here.

Our spectrometer sensors are based on cutting-edge, transmission grating technology. Continuous (not stepped) goniometer movement makes it possible to complete a C-plane measurement in only 30 seconds. This makes the data acquisition time for a light measurement exceptionally fast.

VISO PHOTOMETRY is also Impressive software

The Light Inspector ® is easy and intuitive to use – yet gives you all the details you would expect and a lot more.

The dashboard gives you a live preview of the measurement. Underlying menus enable you to set your own measurement preferences. Measurement data can be exported in every detail or as customized pdf reports.

Your inputs to our software developers are important to us – improving the software and adding features to make your laboratory even smarter is key to Viso’s success.

Compact design 

Viso offers a full-fledged light measurement system that can be fitted in almost in any building. Our biggest system only needs a space of around H2.5 x W2.5 x L10 m to make the perfect laboratory.

Our smallest system fits into a suitcase and can be brought with you everywhere, even on air flights.

VISO PHOTOMETRY: Built-IN power analyzer

All Viso goniospectrometer systems include a built-in power analyzer. Hence, given that you have a steady mains supply there is no need for an external power supply. The system will analyze the power situation in every measurement. Automatic start-up procedures will guarantee proper light source warm-up and steady power feed during test. Output data includes power data, efficacy, and even power and displacement factors.  

automatic ambient light compensation

To measure light, i.e. to capture the luminous flux emitted from a light source into the room, it is essential to either provide conditions of darkness or to separate the background lighting from that of the measured light. While we recommend making photometric measurements in the absence of ambient light, Viso technology gives you the option of ambient light correction in the Viso Light Inspector software. The data acquisition has two steps: first the background light is measured on its own with the sample light source switched off. Then the measurement is repeated with the light source illuminated. Using Viso’s unique algorithm, the background radiation measurement is then subtracted from the overall illumination and the resulting measured light distribution for the sample light is presented.