Gently open the needle valve and observe how a shorter column of heavier (more dense) fluid in the Well balances a taller column of lighter fluid in the Gauge tube.

• 缓慢地打开针形阀,观察油井中水柱较短的较重(密度更大的)流体是如何与压力计管中水柱较高的较轻流体取得平衡的。