The instrument is a pressure measuring instrument of box transformer, it can directly reflect the internal pressure changes of box transformer caused by environmental temperature changes, observe the normal operation of the transformer.

The oil level meter is suitable for the oil level indication installed on the side wall of medium and small oil-immersed transformer oil storage tank and on-load switch oil storage tank. It is also suitable for the level measurement of other open or pressure vessels. It can replace the connected glass tube level meter with the characteristics of safety, intuitive, reliable and long service life.

The relief valve is mainly used to make the gas pressure in the container does not exceed the predetermined value, when the pressure is higher than the relief pressure (P), the valve will open automatically, let the gas escape, when the pressure is lower than the relief pressure (P), the valve will close automatically. In addition, the user can pull the ring at any time to open the valve to lower the pressure.