9
(eyes moving relative to the light source). For the first two, good metrics for the
effect on people has been established: the two indices P
st
LM
and SVM.
SVM -
‘Stroboscopic visibility measure’
Invisible flicker / stroboscopic effects typically occur in the frequency range from 80
Hz to 2,000 Hz and are measured by the SVM measurement method (the
abbreviation stands for "Stroboscopic Visibility Measure"). SVM quantifies the strobe
effect that may occur in connection with moving objects and a light modulation.
Above 2000 Hz there is usually no risk of strobe effects. SVM is based on several
parameters like: Intensity, flicker Index, frequency etc.
The SVM value can be read as:
▪
SVM < 1
Not Visible
▪
SVM = 1
Just Visible
▪
SVM > 1
Visible
P
st
LM
Visible flicker typically occurs when the frequency is from 0.3-80 Hz. In this area the
metric P
st
LM
is used (the abbreviation comes from "short term light modulation").
The details are described in IEC / TR 61547-1 and IEC 61000-4-15.
The P
st
LM
values in general can be read as:
▪
P
st
LM
<= 1
Good
▪
P
st
LM
= 1
50% detection level
▪
P
st
LM
> 1
Bad
Using the menus
Main menu
Press the multifunction button/dial once to enter the main menu:
Press once again to go back
Turn button right to scroll down/left to scroll up and to move the arrow to other
menu point, the press the button once to choose a particular menu point:
▪
Signal Presets
–
allows you to choose between 26 preset signals, see
section
Back
Signal Presets
Custom Signals
Signal Generator
LED
OFF
BNC Out
OFF
