IEC60268-16:2020 ED5 conformance test report V1.102

STIPA algorithm implementation and testing has been done by Dr-Jordan-Design
www.dr-jordan-design.de

Annex C: Verification of STI measuring devices

IEC-60286-16 revision 5 requires manufacturers to verify STIPA implementations according to Annex C.
The main goal of the test signal test bench is to verify that the STI algorithms have been properly implemented.
To test the MTF extraction algorithm, test signals have been generated based on sine-wave carriers (instead of noise carriers) with an intensity modulation depth from 0.0 to 1.0 in 0.1 steps.
Sine wave carriers have been used to reduce the uncertainty.
STI and TI values supposed to be similar, if all bands yield the same TI-value and level dependent features have been disabled.

Settings

Sample rate: 48000Hz
Mode: processing via DFT

Filter phase testing for STIPA direct Method- A.3.1.2 p49

This test generates STIPA signals with carriers at the edges of the generation bands (1/2 octave wide around each octave).
Auditory masking is off.
The phase response of the analysis filter should not yield a systematic error higher than 0, 01 STI for the(S)TI range[0, 1 - 0, 9](equal to the SNR range[-12 + 12]).

Mod. Index TI ref TI max deviation
0.00 0.00 0.000
0.06 0.10 0.001
0.11 0.20 0.001
0.20 0.30 0.001
0.33 0.40 0.000
0.50 0.50 0.000
0.67 0.60 0.000
0.80 0.70 0.001
0.89 0.80 0.001
0.94 0.90 0.002
1.00 1.00 0.000
Testresult: PASSED

Check Transmission Index (TI)

This test generates STIPA signals with sine carriers centered in each octave band.
Auditory masking is off.
The maximum TI error should not exceed 0.02

Mod. Index TI ref TI max deviation
0.00 0.00 0.000
0.06 0.10 0.001
0.11 0.20 0.002
0.20 0.30 0.002
0.33 0.40 0.002
0.50 0.50 0.002
0.67 0.60 0.004
0.80 0.70 0.005
0.89 0.80 0.009
0.94 0.90 0.018
1.00 1.00 0.000
Testresult: PASSED

Filter slope testing for STIPA direct Method- C.4.2 p61

Octave-band filter slope is check with a 100% modulated sine carrier in the band under test. In the lower and upper band a pure sine tone is used. This level is 41dB higher with respect to the band under test.
For each band we test the the upper and lower slope separately.
Auditory masking is off
The modulation indices in the observed band must be >0.5

band min mod. index lower slope min mod. index upper slope
125Hz 0.91 0.91
250Hz 0.91 0.91
500Hz 0.91 0.91
1000Hz 0.91 0.91
2000Hz 0.91 0.92
4000Hz 0.89 0.96
8000Hz 0.83 1.00
Testresult: PASSED

Weighting factors testing for STIPA direct Method- A.2.2 p47

Noise band carrier signals are replaced with pure sine carriers
Two neighboring bands are modulated
Auditory masking is off
Maximum allowed deviation for STI is 0.01

band combination STI ref max deviation
125Hz + 250Hz 0.13 0.009
250Hz + 500Hz 0.28 0.001
500Hz + 1000Hz 0.40 0.002
1000Hz + 2000Hz 0.53 0.001
2000Hz + 4000Hz 0.49 0.004
4000Hz + 8000Hz 0.30 0.002
Testresult: PASSED

Reference generator from wavfile

Modulation index is 1.0. Target STIPA is 1.0

test file (100s) 'C:\Users\jordan\Documents\Messungen\Temp\STIPA_ED5_ref_M=1.00.wav'

Results:
STIPA=1.00

Modulation indices:
Mod. index 1 Mod. index 2
0.97 0.99
1.02 0.99
1.00 1.00
0.99 1.00
1.00 0.99
1.00 1.00
1.00 1.00

Testresult: PASSED

Reference generator to memory

Modulation index is 1.0. Target STIPA is 1.0

Results:
STIPA=1.00

Modulation indices:
Mod. index 1 Mod. index 2
1.11 1.04
1.01 0.92
1.03 1.02
1.00 0.99
0.99 0.99
1.00 1.00
0.98 1.01

Testresult: PASSED

Modulation depth testing for STIPA direct Method- Annex C.3.2 p59ff

Noise band carrier signals are replaced with pure sine carriers
Modulation index is swept from 0 to 1. This modulation index is used for all bands and both modulation frequencies.
Auditory masking is off
Maximum allowed deviation for modulation index is 0.05
Maximum allowed deviation for STI is 0.01

M index max deviation STI ref max deviation
1.00 0.01 1.00 0.000
0.00 0.00 0.00 0.000
0.03 0.00 0.00 0.000
0.06 0.00 0.10 0.002
0.10 0.00 0.18 0.002
0.11 0.00 0.20 0.003
0.20 0.00 0.30 0.001
0.30 0.01 0.38 0.003
0.33 0.01 0.40 0.002
0.40 0.01 0.44 0.001
0.50 0.01 0.50 0.000
0.60 0.01 0.56 0.001
0.67 0.01 0.60 0.003
0.70 0.01 0.62 0.003
0.80 0.01 0.70 0.001
0.89 0.01 0.80 0.003
0.90 0.01 0.82 0.001
0.94 0.01 0.90 0.001
0.97 0.01 1.00 0.000
1.00 0.01 1.00 0.000
Testresult: PASSED


Total result of all IEC60268-16 ED5 tests

Testresult: PASSED