if a unit for something is being measured, then it requires a measurement tool for measuring that something
metric_unit_of_measure is not unit_of_measure. meter is measuring_instrument. metric_unit is unit_of_measurement. metric_unit is not unit_of_measurement. system_of_measurement is measure. reading is measurement. metric_unit_of_measure is unit_of_measure. measuring_unit is unit_of_measurement. measuring_unit is not unit_of_measurement. mental_measurement is not measurement.