Laser Instruments and Instrumentation
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Laser Radar Instrumentation depends on knowing the speed of light, approximately 0.3 meters per nanosecond. Using that constant it is calculated how far a returning light photon has travelled to and from an object: Distance= (Speed of Light x Time of Flight) / 2. It works as follows;
- Laser generates an optical pulse.
- Pulse is reflected off an object and returns to the system receiver.
- High-speed counter measures the time of flight from the start pulse to the return pulse.
- Time measurement is converted to a distance by using the formula above
Laser Technology is utilised in accurate Laser Instruments for Industrial Level and Measurement Applications.
Reflectivity of the Object
Measurements are not generally affected by the reflectivity of the Object . Highly reflective objects may saturate some laser detectors, while the return signal from low-reflectivity objects may occasionally be too weak to register as valid.
Day or Night
Laser radar is an "active illumination" technique that, unlike photography, does not depend on ambient illumination. It works during the day or at night.
Sunlight and Reflections/Angle of Measurement
A strong sunlight reflection off a highly reflective target may "saturate" a receiver, producing an invalid or less accurate reading. However, laser measurements are not usually affected by other reflections.
Dust and Vapour
Laser measurements can be weakened by interacting with dust and vapour particles, which scatter the laser beam and the signal returning from the target. However, using last-pulse measurements can reduce or eliminate this interference.
Target's Angle of Repose
Laser measurements can be made to targets at any angle.
Background Noise and Radiation
Laser Measurement is not affected by background noise. Instrumentation generally determines baseline radiation levels to ensure that it does not interfere with measurements.
Temperature and Temperature Variations
Laser measurements are based on the speed of light and are unaffected by temperature variations.
Vessel Pressure and Off-Gas Layers
Laser Measurement is unaffected by pressure or vacuum variations, or off-gas layers.
Thanks to OPTEK for the above information.
Laser Level Instrumentation and Measurement
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