今天翻译文章时看到的，用石油大典翻译是这样
fluid head—流体压头 fluid head loss—流体压头损失
能跟我解释下这是什么东东吗？从来没见过啊
相关段落如下：
passenger1：Today’s pressure sensors also have the ability to measure pressure changes that are several orders of magnitude less than in 1967 so provides the versatility to install the sensor on the discharge where there is a physical change in fluid head above the BOP as Harrison did, similarly on an open pipe to measure the change in head or on a closed pipe that remains full and measures the change in friction pressure.
passenger2：
The earliest mention of a pressure sensor for kick detection on the annulus discharge was a Foxboro fluid-head indicator
installed in the bell nipple that was capable of detecting 1 in. of water pressure (Otto R. Harrison 1967). The height of the mud
in the bell nipple would change according to the mud flow rate and therefore indicate a kick if pressure increased. A WATCO
mud-flow meter was also recommended. These can be likened to the pressure sensor and Coriolis flow meter which are in use
today. It is understandable that for an open return system the tendency would be to use a flow meter since a pressure sensor on
the bell nipple may not be effective in measuring fluid height depending on the angle, size and type of flow line in use. We are
now using a closed and pressurized annular discharge system but until today we remained focused on using a flow meter
instead of using the pressure sensor which is ideally suited for kick detection as well.
