What should be used to test pressure in gas lines?

Using a manometer or pressure gauge is essential for testing pressure in gas lines because these instruments are specifically designed to measure pressure accurately. A manometer provides a visual reading of gas pressure and is effective for both low and high-pressure systems. It operates by comparing the pressure of the gas to atmospheric pressure, which allows for precise measurements.

Pressure gauges also offer a straightforward means of monitoring pressure within gas systems. They provide immediate feedback on pressure levels, ensuring that the system is operating within the safe and recommended pressure ranges. This is crucial for preventing leaks, ensuring safety, and maintaining the efficiency of gas appliances and lines.

The other options, while they serve their own purposes, would not be suitable for this specific application. Thermometers, for instance, measure temperature and do not provide any information about gas pressure. A digital pressure sensor could potentially be used, but it may not be as commonly utilized or have the same level of reliability and ease of use as traditional manometers or gauges in the field. Similarly, a water column gauge can measure pressure, but it is less common in practical applications for gas lines compared to the more universally accepted manometer or pressure gauge.