For water leakage:
First of all, it depends on where the water leakage occurs, generally at the floor drain, pipe root, corner, doorway, etc. You can judge the water leakage trace from the downstairs, and only need to dig some tiles to make waterproof repair, and the maintenance time is also very short;
if none of the above is, it may be that the concealed pipe is leaking, you can do a pressing test to confirm that it is a pipe problem before you chisel the tiles;
If it's an old house with serious water leakage and prefabricated panels, and the water is pervasive, it's recommended to dig it all up and make it waterproof again;
grouting waterproof on the back water surface is really a temporary solution, not a permanent cure.
The equipment for detecting water leakage points you mentioned is the equipment for detecting water leakage points of water pipes, which is also called "stethoscope".
it is suggested to find a professional waterproof company to solve the problem, sign a maintenance contract, and explain all the water-using equipment in the kitchen to the master during maintenance, so as to avoid misjudgment.