In order to accurately measure very low...

🔍 Key Concepts

• Differences between elastic mechanical gauges (like Bourdon tubes and compound gauges) and liquid column devices • Which instruments are best suited for very small, low positive pressures close to atmospheric pressure • How sensitivity and accuracy change with the type of pressure-measuring device

💭 Think About

• Which of these instruments can show a very small change in pressure as a relatively large, easily measured change in the instrument reading? • Think about which instrument is commonly used in laboratories or calibration setups when extremely small pressures or pressure differences must be measured. • Which devices here are typically used on shipboard machinery for medium/high pressures, and which are used for precise low-pressure measurement?

✅ Before You Answer

• Identify which option uses a column of liquid whose height changes with pressure. • Eliminate instruments that are primarily designed for high or combined positive/negative pressures, not for very low pressures. • Ask yourself: Which instrument is known for high sensitivity and accuracy in measuring small pressure differences?

In order to accurately measure very low positive pressures, which of the instruments listed should be used?

Compound gage

Bourdon tube

Manometer

Deadweight gage