紅油壓差表是一種用于測量正負壓差的儀表，廣泛應用于藥廠、電子廠潔凈廠房和暖通空調過濾網等場所。其工作原理基于液體內部壓強公式P=ρgh，通過兩個不同壓力產生的液柱高度來顯示壓差。該儀表具有超低量程、廉價、結構牢固的特點，并且可以固定安裝在任何垂直表面上。

       Red oil pressure difference meter is a kind of instrument for measuring positive and negative pressure difference, widely used in pharmaceutical factory, electronic factory clean workshop and HVAC filter screen and other places. The principle is based on the internal pressure formula p = ρ g h, which shows the pressure difference by the height of the liquid column produced by two different pressures. The instrument has the characteristics of ultra-low range, low cost, strong structure, and can be fixed on any vertical surface.