We should understand that although rangefinders report measurements to at least one decimal place, there is some amount of error inherent in these measurements. A number of factors contribute to this error, including the quality of the rangefinder, the distance to the target, stability of the rangefinder when taking the measurement, magnetic interference, characteristics of the target, poor weather, and daytime solar conditions. Some rangefinders have options to minimize error, such as a poor weather setting to minimize the impact of rain, snow, smoke, or airborne dust particles. The best approach to minimizing errors, however, is to be aware of the above factors, and to select a rangefinder that is appropriate for your application needs.
The three most important factors for introducing error are:
1, The quality of the rangefinder: The quality of the rangefinder is directly proportional to the cost of the rangefinder. More expensive rangefinders use better quality components and as a result provide more accurate measurements at greater distances. Less expensive rangefinders provide less accurate measurements, and are only suitable for measuring shorter distances.
2, The distance to the target: The measurement error increases as the distance from the observer to the target increases. For example, a compass error of 1 degree for a bearing measurement results in a horizontal error of 1.75 feet at a distance of 100 feet, and 8.73 feet at a distance of 500 feet.
3, When mapping the location of an object which is inaccessible, either because it is difficult to get to or it is not safe to get to the object. For example, a tree on an island, or a manhole in the middle of a busy road. When mapping the location of an object where it is not possible to get a GPS signal, or a GPS position of sufficient accuracy. For example, under a large tree or in a narrow street or ‘urban canyon’.
How to achieve maximum accuracy
It can sometimes be difficult to target small objects at large distances when holding the rangefinder in your hand without any stabilizing support. The pointing stability: To achieve maximum accuracy, it is recommended that you use a range pole, monopole, or tripod to stabilize the rangefinder—especially when measuring large distances.