Abstract: A sensing apparatus of a Broudon pressure gauge is disclosed, which comprises a magnet which has a N pole and a S pole at one end between both ends of the shaft which its connected with the displacement gear and rotates; a sensing unit which is provided in the body at a portion corresponding to the magnet and is disposed on at least three portions in circular directions and includes an AMR sensor or hall sensor for sensing the rotation value of the magnet; and a display control unit which receives a sine signal value and a cosine signal value among phase signal values from the sensors of the sensing unit and corrects the phase values and outputs to the LCD.

Abstract: An oil checking device for compressor of air conditioning system includes an oil container connected to an high-pressure part of the air conditioning system to receive refrigerant and oil from the high-pressure part, the oil container being formed of a transparent material so that a user can observe the oil mixed with the refrigerant, a valve member for selectively opening a gas line and a liquid line respectively connected to upper-inner and lower-inner portions of the oil container to exhaust refrigerant gas and compressor oil from the oil container to a low-pressure part of the air conditioning system, a ball floater disposed in the oil container, and an oil amount/state display part formed on the oil container, the oil amount/state display part having a reference oil level that can be compared with the compressor oil level and a reference color that can be compared with a color of the compressor oil.