The  hysteresis is the feature of the instrument toprovide different reading values at the same measurand when it varies for increasing values and decreasing valuesHysteresis is therefore an essential feature for instruments that can measure both increasing and decreasing values, such as dial indicators, pressure gauges, force gauges and so on. If a measuring instrument is subject to hysteresis, but its use is only for increasing or decreasing values, the maximum error evaluation can exclude hysteresis and thus is not used to estimate the measurement uncertainty. (see chart below).