U S E R M A N U A L D A Y C O R ® S U P E R B
7
LI – Long Integration
L
ong
I
ntegration supports inspection of very weak signals or inspection in areas with
abundant non-corona UV background signals. This function affects the read-out
frequency of frames. Below is an example taken from a distribution line in Costa Rica
(a 35 kV line) where a nearby welding machine generated non-corona UV background.
While in long integration, the CCD of the UV channel is read-out in a lower rate and
each read-out contains the accumulated UV events. Therefore, the UV signals that
repeat in the same place (corona for example) form a larger signal while the random
signals almost do not increase in size. By reducing the UV gain, the random UV signals
can be removed while the repetitive signal, although decreasing in size, will still be
visible on the screen. More in Chapter 3.
Counting
The counting function provides an indication of the corona strength. The camera
displays the number of UV spots generated by corona per minute.
(*)
Counting results depend on:
a.
Distance and angle of the camera from the corona source
b.
Relative ambient humidity. The higher the humidity, the more intense is the
corona activity and the higher is the count
c.
Camera settings. Each camera has its innate recommended gain range. This
value is documented in the manufacturer's instruction manual supplied with
each camera. Within this gain range the dependency of the counting on the
UV gain is minimal (plateau range). In other words, within this plateau range
the counting values will be similar in various gain values.
No Integration LI=0 UV Gain 180
Long integration L3, UV Gain 90
