Noptel Rail Track/Bridge Laser Alignment and Displacement Measurement
Noptel Oy specialises in the design and manufacture of innovative optoelectronic products based on its own focused technology know-how. Products include the PSM-200 measuring device especially developed for measuring the alignment of rails, and the PSM-90 for the dynamic measurement of large constructions e.g. bridges.
Noptel’s position-sensitive measurement technology permits deflection measurement of constructions in operating distances of several hundred metres, giving a resolution of up to 0.01% of the measuring range.
The measuring range can vary from a few millimetres to several meters, and the measuring speed can be over 1,000 readings/second. The measurement can be done on one or two axes. In railway track measurement the systems can be used for measuring the longitudinal profile and alignment of rails.
Measurement devices that employ this technology can be light in weight, robust and are very suitable for outdoor use. The PSM-200 measuring device has been developed especially for measuring the alignment of the rail. It is based on a laser transmitter and an optoelectronic receiver. The operator directs a safe, visible laser beam at the receiver and locks it in a steady position. The receiver recognises the beam on the optical target and measures its position accurately up to 100 times a second.
The PSM-90 measuring device is meant mainly for dynamic measurements of large constructions like bridges. The measurement results can be transferred to a computer through a serial interface or they can be recorded to standard data logger unit. The detection technology allows reliable measurement under variable environmental conditions.
Railway bridge measurement
A potential application for laser-based position-sensitive measurement technology is measurement of the dynamics of large constructions like bridges, towers, buildings and masts and movement of other moving objects.
The results obtained in applications show that the system provides valuable information for evaluating the design criteria or expected behaviour of large constructions under changing loading conditions.
Due to the good transportability and reinstallability of the measuring system, the same equipment can be used in many different applications as well as in fixed installations. The measuring speed is high enough to analyse even the fastest movements of constructions and the resolution and accuracy high enough for the smallest deviations encountered with rigid constructions.
Railway track control
Laser alignment measurement technology has been applied to railway track maintenance. This system employs Noptel’s highly advanced laser-beam hit point detection technique, which measures the position of the railway track in two dimensions with a high degree of accuracy and helps the vehicle’s track reinforcement mechanism to adjusts the rail rapidly and precisely to the reference position.
The same system can be installed to a lightweight trolley to manually measure the longitudinal profile and alignment of the rail. This gives the operator accurate measurement information about the faults in joints, curves and lines.