SVS-Vistek HR Series, Manual

Page: 45 / 102

SVS-VISTEK
Feature description 45
6.2.15 PIV
By using PIV mode on CCD sensor cameras it is possible to capture 2
images within extremely short time.
Based on the “interline transfer” of CCD sensors, in the PIV mode the first
picture is transferred to the vertical shift register, while the second picture
is taken. The readout of picture 1 will take place during the second
exposure time.
So the time between 2 images can be shortened to transfer time only –
contact us (@ SVS-VISTEK.com) for camera and sensor specific minimum
transfer time/duration.
„Triggered with external exposure“ (via pulse width of the Exsync signal)
or alternatively „triggered with internal exposure“( set via internal
microcontroller). This is useful for ”particle image velocimetry” (PIV).
The first exposure starts approx. 5 µs after the camera has detected the
rising edge of Exsync.
Figure 16: PIV mode
The read-out time 1 and the exposure time 2 start both directly after the
image transfer of image 1. The exposure time 2 ends when the read-out
of image 1 has finished. After the read out of image 1 is done, image 2 is
transferred and read out. The readout time of each camera is sensor
dependent. Please contact the SVS-Vistek support team for details on
sensor readout timing.
During the read out of the 2nd image the camera cannot take images
until the next Exsync signal (rising edge) arrives and initiates the next
exposure cycle.
Without PIV-Mode enabled, all camera modes like “free running “or
“triggered with internal exposure control“ function as described.