Place an Accutek Tell-Tale gauge anywhere in the line you want to check for leaks or pressure loss. Set the adjustable needle to the same pressure as the gauge needle and wait. If, over time, the pressure gauge needle drops below the Tell-Tale needle, the system is losing pressure.
Specifications: 2.5" face, 1/4" NPT bottom mount, 0-160 PSI (0-1100 kPA)