Anyone who has ever worked in practice with a laser distance meter knows that range and accuracy strongly depend on the reflection characteristics of the target and the lighting conditions. There is no use if the manufacturer claims large ranges for marketing purposes, however this performance ca exclusively be achieved under perfect laboratory conditions.
The practitioner wants to reach this precision in everyday life on the job site. There has been a discrepancy between advertising and reality, because each manufacturer could measure the way they like and under ideal conditions. These results could then be used for advertising purposes and comparisons. The ISO standard 16331-1 was developed to standardize comparisons in the future. It regulates how laser range finders are assessed and thus improves comparisons.
Leica Geosystems was involved in developing the standard. They were also the inventor of the hand-held laser distance meter. They specify their instruments for practice, so that they can fulfill the promise from the packaging at the construction site. As already mentioned this means that range and accuracy reach the specified values in the practical working environment and not only under optimal laboratory conditions.
Various factors have a great influence on the maximum range and the achievable accuracy. These include the strength of the ambient light, the surface structure and color of the measurement target as well as the temperature at which is measured. Without the ISO standard, these parameters were not further defined, so that each manufacturer could use their own definitions according to his will. For the customer it became therefore increasingly difficult to compare in the growing market of laser rangefinders. Here, everyone knows from practice, how important accuracy and reliability are as imprecise or misleading information can lead to serious and very expensive in doubt measurement errors.
The new ISO standard 16331-1 defines in detail how information on range and accuracy has to be indicated and which measurement procedures must take place. The normalization means that the information published by a manufacturer can be tested by independent institutions. Ensuring that data can be compared to other laser distance meters by different manufacturers.
- The buyer of a specified according to the ISO standard laser rangefinder can draw conclusions about the achievable accuracy and attainable range under similar measurement conditions. This is crucial if one wants to estimate the use of a laser distance measuring device for use on the construction site.The ISO standard 16331-1 considers the following measurement conditions, as they also occur in practice:
- favorable measurement conditions, as they occur very frequently in interior applications:
- Low ambient lighting of 3,000 lux
- Measurement on a white painted wall
- Measuring at room temperature
- unfavorable measuring conditions, such as occur frequently in outdoor applications:
- strong sunlight with 30,000 Lux
- Measurement on a white painted wall
- Measurement in the whole range of the operating temperature
- Also, other measurement conditions are specified, for example:
- Measurement to a defined target plate
- Measurement rather unfavorable measurement targets with weak or strong reflection such as wet concrete or metal surfaces
Who wants to take a deeper look into the ISO standard 16331-1, can read there about the following points: reflection of the measurement target, backlight, temperatures of the main components, atmospheric effects, resolution of the display, average error and measurement uncertainty, influence on the uncertainty, test procedures, conditions, location of the measurement points, calculate the deviations and the measurement uncertainty.
The following laser distance measurers meet the ISO 16331-1: