Low pressures and vacuums are typically measured with which instrument?

Low pressures and vacuums are generally measured using a manometer because this device is specifically designed to measure pressure differences and can effectively show both positive and negative pressures (or vacuums) in a fluid system. Manometers utilize a column of liquid—commonly mercury or water—where the height difference in the liquid column directly indicates the pressure. This allows for easy readings of low pressures and can be calibrated to measure vacuum pressure as well.

By using a manometer, operators can accurately gauge how much pressure is below atmospheric levels, which is crucial in many applications, such as in vacuum systems or in processes that require controlled low pressure environments. The simplicity and effectiveness of this device in measuring low pressures make it the preferred choice in such scenarios.

Other instruments mentioned, like transducers or rotameters, serve different functions: transducers convert pressure into an electrical signal for measurement and display, while rotameters are primarily used for measuring flow rates, not directly for measuring pressure. Using kilopascals (kPa) is a unit of measurement rather than an instrument and does not pertain to the specific method of measuring pressure or vacuum.