Consumer Electronics Quality Tests and Certifications

measurements

Weaknesses in signal quality can render a device, or a whole signal chain, unable to achieve its full potential. As a specialized and experienced test laboratory, we therefore determine the quality of the audio and video connections with meticulous accuracy:
- objectively, with the help of measuring devices
- subjectively, thanks to the long and established experience of our specialists
- reproducibly, thanks to precisely specified limiting values and sophisticated, documented test procedures.

Particularly because of our intensive collaboration with the specialist press, we never lose sight of what is feasible, or of the market’s requirements.

audio measurements

For example, we test the following audio criteria:
- maximum output power at various impedances (for amplifiers, for example, quoted in watts)
- sensitivity (for loudspeakers, inputs and tuners)
- noise level (signal to noise ratio, SNR)
- sound fidelity (frequency response, level deviations within the frequency range)
- channel separation (crosstalk L/R)
- distortion (THD+N, total harmonic distortion)
- digital sound quality (jitter)
- impedance response (for example the minimum impedance of loudspeakers)
- speed fluctuations (wow and flutter)

Tests relating to sound quality – The test lab at AV T.O.P. Messtechnik offers many forms of audio measurement: for example, loudspeakers, amplifiers, headphones, set-top boxes and all kinds of players.

video measurements

For example, we test the following important aspects of video quality:
- picture resolution (video frequency response)
- grayscale linearity (gamma)
- color fidelity (vectorscope, CIE chromaticity diagram)
- false edge formation (overshoot of 2T pulse and moved contours)
- distortion (geometric distortion)
- signal level (white level, black level)
- stability (field jitter, line jitter)
- contrast ratio (measured according to ANSI, in-picture and On/Off)
- maximum brightness (Lumen or cd/m²)
- video processing (deinterlacing, scaling)
- tuner sensitivity (measured in dBµV)
- visual test (subjective, carried out by specialists)

Alongside standard SDTV measurements, we are also in the position to offer HDTV measurements:
- picture quality analysis of the HDMI output
- protocol checking (EDID) of the HDMI output
- self-declaration for HD standards “HD ready” and “HD ready 1080p”

Vector diagram – With the help of our measurement devices, the color coordinates of the electrical video outputs can be determined just as precisely as TVs and projectors can optically.

 

optical measurements

In terms of optics, for example, we test the following important quality criteria:
- color space
- color coordinates / color temperature
- gamma / grayscale linearity and gray tracking
- resolution
- brightness
- contrast (also ANSI)
- viewing angle (contrast, color shift, brightness)

For the measurement of colors, we use a Minolta CS-2000 spectrophotometer, among others. This outstanding device is able to measure precise color levels even at 0.003 cd/m².