What is the main reason for using a sloped tube manometer over other types of pressure gauges?

A sloped tube manometer is favored primarily because it provides high accuracy for measuring low pressures. The design of a sloped tube allows for a greater length of liquid column, which enhances the resolution of the pressure measurement. This means that even small changes in pressure can be detected more accurately compared to other types of gauges.

In applications where precise readings are necessary, especially those involving low-pressure scenarios, a sloped tube manometer is an excellent choice. The slope increases the distance over which the height of the liquid can change in response to pressure variations, amplifying the effect of small pressure differences. This level of precision can be critical in many gas technician tasks, such as ensuring safe operating conditions in gas systems.

While other options may present benefits, such as cost-effectiveness or portability, they do not provide the specific high accuracy for low pressures that the sloped tube design excels in, making it the preferred tool for applications necessitating precise pressure measurements.