Flow measuring instrument type ultrasonic seal has the advantage is there's no khwangkrasae of any device, so there is no flow, the pressure loss values from a measurement occurs, correct values. Measuring tool can be installed to articulate at the pipe wall without stop working. By the installation location should be away from the pump, or frequency sources that may cause interference. Measurement points should be selected and no corrosion of the pipe or the pipe surface rust around the island.