Measuring Pipe Deformation with Ring Laser

This article explain what has to be considered while recoding video to use with the laserscan.
The end part describes how to position the calibration rings or the calibration points.
For maore details please read the Laserscan manual.

Instructions

Range of operation
• Investigation of pipe line systems, which have to satisfy
high demands on material stability.
– Hydropower plants (stability examination of high
pressure pipes)
• Warranty assessment of high performance drainage
systems for objects like…
– Tunnels and bridges
– Highways
– Airport Runways

Prior to the survey

• Pipe cleaning: removal of floating deposits
• Removal of encrustations to reduce light reflexions on
pipe wall or pipe ground
• Block water flow in order to get the pipe ground visible

Run the survey

Prior to the scan

• Center camera head
• Set Laser ring diameter to 75% of image height
• Set recording format to MPEG2 in order to increase
accuracy of measuring results
• Place the whole length of the calibration bar within the
camera view angle
• Cover the manhole in order to avoid light intrusion at the
beginning of recording a video clip

During the scan
• Switch off the light and text display: only the laser ring
must be visible
• Increase the light intensity of the laser ring at larger
diameters accordingly
• Decrease image luminosity in order to get disturbing red
sparks disappeared
• Scan with a constant low speed (max. 17 cm/sec) in
order to avoid jerky movements of the camera head.
• Keep the camera head centered during recording
• Record a sequence showing the entire calibration bar
(100 mm - 600 mm)