More meaningful comparisons can be made by comparing water loss from the potometer with that from an atmometer ( an apparatus used to measure the rate of evaporation from a porous pot or other nonliving wet surface ) , which allows uncontrolled evaporation 更有意义的是，可以比较蒸腾计的失水与蒸发计（通过有孔小罐或者潮湿表面来测量蒸发速率的仪器）的失水间的区别。
