What are favorable/unfavorable measuring conditions?
Favorable/average measuring conditions:
Materials with good reflecting characteristics, meaning they reflect the laser beam in a divergent (not mirrored!) manner.
Laser dot is brighter than the ambient light Operating within the allowable temperature range (-10° + 50° C)
Unfavorable measuring conditions:
Highly reflective surfaces
Highly absorbing surfaces, such as wet or dark surfaces
Operating at the limits of the allowable temperature range
Not waiting for temperature calibration
Very intensive ambient light
For optical and safety reasons, do not measure against colorless liquids (water) or glass
How accurate is Leica DISTO™ at 0.5m, 1m … to 200m?
The measurement deviation for Leica DISTO™ devices is not directly proportional to the measured distance. Therefore the accuracy of a Leica DISTO™ remains constant until a range specified in the manual. After this range the accuracy will change by a value proportional to the distance which is also specified in the operation manual. In many cases a maximum measurement deviation will not be exceeded.
E.g. the Leica DISTO™D3 is having an accuracy of 1mm up to 10m. After this the deviation will increase by 0,025mm/m (so at 30m the accuracy will be 1,5mm). After 30m the deviation will increase by 0,1mm/m (at 100m the measurement deviation might be 8,5mm).
Please note that measurement conditions may have an influence on the accuracy. Read more about this in the FAQ for "typical accuracy". The tolerance is not proportional to the measured distance, it is the same over the entire distance. However, over long distances, additional errors of +/-5 ppm (parts per million) (+/-0.5mm/100m) come into play.
How can I monitor my measuring equipment on my own?
Monitoring of measuring equipment for Leica DISTO™ –users who perform the required monitoring themselves, in accordance with their quality management systems: Measure an easily accessible distance of 2 to 10 m with a distance measuring instrument approved by your national bureau of standards. Make 10 measurements over the same distance. Determine the deviation of your measurements from the actual distance and calculate the standard deviation from the results. Record the value and set the time for the next series of measurements. Repeat these check measurements regularly, especially before and after important measuring tasks. Mark the Leica DISTO™ with an”inspected” sticker and protocol the entire monitoring process. Your Leica DISTO™ meets the specified accuracy, if the standard deviation is equal to or less than the value stated as the typical standard deviation. A Leica DISTO™ checked on the test distance works with the specified accuracy over the entire specified measuring and temperature ranges. For more information please download enclosed PDF