NATE Gas Heating Practice Exam

Which instrument is used to measure outlet gas pressure?

1. Velometer

2. Anemometer

3. Monometer

4. Draft gauge

The correct answer is: Monometer

The correct instrument used to measure outlet gas pressure is a manometer. A manometer is specifically designed to quantify pressure differences and is commonly used for measuring gas pressures in heating and ventilation systems. It operates based on the principle of balancing liquid columns and can provide accurate readings of both positive and negative pressures. Understanding the function of a manometer is essential in the context of ensuring proper gas pressure within heating systems, which is critical for efficient operation and safety. When checking the outlet gas pressure of a heating appliance, a manometer allows technicians to confirm that the pressure is within the manufacturer's specified range, which affects combustion efficiency and system performance. In contrast, a velometer is used to measure the velocity of gas or air flows, an anemometer measures wind speed or air movement, and a draft gauge typically measures the draft conditions in flue systems but does not directly measure gas pressure. Therefore, the specificity and accuracy of a manometer make it the right tool for measuring outlet gas pressure.