What is the term for dropping a weighted string down the barrel of a fire hydrant to check for water?

The term "stringing" refers specifically to the practice of dropping a weighted string down the barrel of a fire hydrant to check for the presence of water and to measure the water level. This method allows technicians to assess whether the hydrant is functioning properly and if there is sufficient water available for firefighting purposes.

The other options represent different practices related to fire hydrants. "Testing" generally covers a broad range of evaluations performed on hydrants, which can include flow tests or pressure checks, but does not specifically refer to the string method. "Hydrant flushing" entails opening hydrants to clear sediment and ensure clean water flow but does not involve the use of a string. Meanwhile, "hydrant inspection" pertains to a comprehensive review of the hydrant's condition, functionality, and accessibility, which also does not include the specific action of using a weighted string. Therefore, "stringing" is the precise term that describes this method of checking for water in the hydrant.