The measuring range of a measuring instrument according to DIN 1319 -1 that portion of a measured variable , in which the variations in measurements or measuring instruments variations remain within predetermined limits. The specified error limits are only valid in the defined measuring range. If the measuring range on a scale display does not match the entire scale length, the measuring range limits must be clearly marked; see EN 60051 . Outside of the measuring range, nothing is guaranteed for accuracy. Every measuring device has a certain output or display area in which it can provide information about the measured variable. This often, but not necessarily, corresponds to the measuring range.
The distinction between measuring and display range is only possible with a scale display ; an example is shown in the adjacent picture. For measuring devices with a numeric display , the measuring range is always linked to the display range. The four-digit display occurs particularly frequently, in which only the digits 0 and 1 are implemented in the leading digit. For the existing display range 0000… 1999, 1 digit more is specified as the measuring range , e.g. B. smooth 20 V (instead of 19.99 V).
The final value of the measuring range is often the reference value for calculating the error limit from the class symbol if an accuracy class is used as a basis.
The zero point at which the measured variable assumes the value zero is often at the beginning of the measuring range; however, it can also be in the middle or - depending on the measuring method - outside the measuring range.
Typical examples for the measuring range of individual measuring devices:
- A measuring tape 3 meters long has a measuring range of 0 to 3 m with a resolution of 1 mm
- A caliper (with vernier ) has a measuring range of 0 to 14 cm with a resolution of 0.1 mm
- A voltage measuring device has a measuring range of - 10 to + 10 V with a resolution of 0.2 V.
- An electronic distance meter has a measuring range of 0.5 m to 1,200 m
In order to be able to use devices more universally, the measuring range can often be adapted through suitable measures. In the case of an electronic range finder, for example, a larger reflector can be used at the target point in order to enlarge the measuring range upwards. Or you can put a screen in front of it, which emits a weaker light signal in order to expand the measuring range downwards. With a moving coil voltmeter, the measuring range can be increased by adding a series resistor. With measuring devices for use in laboratories, measuring ranges can often be switched, see e.g. B. analog multimeters , digital multimeters .