The new ultrasonic tightness testing technique was originally introduced as an excellent solution to avoid damping of the load due to leaks in the hold hatch covers. The equipment used during the test allows to find the exact location and size of the leak, and it is simple and quick to use. The transmitter, placed in a closed room, emits ultrasonic waves. Outside of the room, the waves that have leaked through any leaks are detected by the receiver. Leak size can be assessed by reading on a digital scale. Ultrasonic tightness testing can be successfully used during production or in operation for testing hatches, windows, doors, etc.