Nullstille

Nullstille is the process of returning a measurement device, instrument, or system to a known zero or baseline state. In practice, nullstilling eliminates residual influence from prior measurements, ambient conditions, or component drift, so subsequent readings can be interpreted against a stable reference point. The term is widely used in Norwegian technical and scientific contexts and is closely related to the English terms zeroing or tare in measurement technology. Typical targets for nullstille include electronic multimeters, balances and scales, pressure and temperature sensors, and software data streams. In scale weighing, tare involves subtracting the weight of a container to obtain the net sample weight, effectively nulling the container's influence.

Methods vary: manual zeroing by adjusting an alignment knob, pressing a zero or tare button, or setting a reference value; automated or self-calibrating devices perform zeroing as part of startup or under specific conditions. In laboratory practice, nullstille may be part of calibration or baseline correction, ensuring that readings reflect only the quantity of interest rather than instrument bias. Distinctions exist between zeroing and full calibration; zeroing corrects zero bias at a moment, whereas calibration establishes a full relationship between instrument output and a known standard.

Limitations include drift due to temperature changes, aging components, or mechanical wear, which may require repeated zeroing or formal calibration against traceable standards. Nullstille is therefore a routine maintenance and quality-control step, not a substitute for proper calibration where accuracy across a range is required.