pV So there is an arbitrary set point that needs to be defined, right? Because what you actually measure in the lab are changes in enthalpy, just like what you measure when you look at energy change of some sort, you measure the change in energy, right.

焓也是一样，焓是U加,所以需要定义一个任意的设定值,对吧？因为实际上你在实验室里,测得的是焓的改变,就像你在研究某种能量变化时，所测量的那样，你测量的是能量的改变，对吧。

麻省理工公开课 - 热力学与动力学课程节选