What does a sounding tube allow an operator to do?

A sounding tube allows an operator to insert a water level measuring device into it for the purpose of monitoring the water level in a well or tank. This device helps in accurately gauging the depth of water, which is crucial for keeping track of water supply levels, ensuring proper pumping operations, and maintaining system efficiency. The use of a sounding tube simplifies the process of measuring water levels without the need to physically enter the well or tank, making it a valuable tool in water management.

While some options may touch on related concepts, none offer the same practicality and functionality as the correct choice. For instance, measuring water level using air pressure can be part of a different method of water level monitoring that does not specifically involve a sounding tube. The watertight seal feature pertains to pump integrity but falls outside the main function of the sounding tube. Admitting air during system shutdown is related to venting but is not a primary function of the device in question. Thus, the primary role of a sounding tube remains its ability to facilitate the insertion of a measuring device.