Diffuse Reflection Issue of Laser Rangefinder for Heating Coils
To reduce measurement errors, most laser rangefinders require a reflective target placed at the measured end to minimize deviations caused by diffuse reflection. How do telescopic laser rangefinders used by snipers overcome this issue?The working principle of laser rangefinders is similar to that of sonar. Are the reflected optical signals highly susceptible to interference from ambient light of different wavelengths and intensities?Humidity sensor probes, stainless steel electric heating tubes, PT100 sensors, fluid solenoid valves, cast aluminum heaters, heating coils.
Pulse‑type laser rangefinders generally adopt avalanche photodiodes as detection components. These devices are only sensitive to light of a specific wavelength. When the wavelength matches, even extremely weak light can be detected; light with mismatched wavelengths, no matter how high the intensity, will not be recognized. Laser features excellent monochromaticity, with 905 nm being the most commonly used wavelength. Therefore, the received reflected laser signals are rarely disturbed by ambient light.
In general, there are two mainstream ranging principles for laser rangefinders: the pulse method and the phase method.
The phase method calculates distance by measuring the phase shift of the returned wave. It relies on cooperative targets, namely the reflective surfaces mentioned above, and operates with relatively low transmitting power.
Telescopic laser rangefinders for snipers mostly apply the pulse principle: a laser pulse is emitted to start timing, and timing stops once the reflected pulse is received, thereby calculating the distance. Without dedicated cooperative targets, diffuse reflection leads to severe optical energy loss, yet this usually does not hinder normal measurement, for the reasons stated above. Manufacturers usually increase the transmitting power to compensate for signal attenuation.
