This device can transmit signal and control through the medium of compressed gas, and can adjust testing pressure, flow rate and time according to the automatic controlling requirement.

Instruments based on the lower limit of two switch-contact device, the pressure to set a signal or when the value of on-off control circuit for the operating system's automatic control or the use.

Different points of the same type, but the difference between the subsidiary device and the automatic control, the part of the structure of the high pressure foaming machine is the same as the same.