Compensation tiny micro pressure gauge used for measuring the corrosive gas pressure, negative pressure and pressure difference, can also be used to calibrate other pressure gauge, available to the laboratory and the measuring unit. Compensation micromanometer by trimming parts, level observation, mirror part and shell parts. Compensation by a micro pressure meter can be moved up and down in the container and a can be connected to fine-tune the stillness of the container, using movable container position change to compensate the measured pressure caused by static container level zero change of liquid column manometer. Used for measuring the corrosive gas tiny pressure, negative pressure and pressure difference, can also be used to calibrate other pressure gauge, available to the laboratory and the measuring unit. 1. Trimming parts - By fine-tuning plate engraved with 200 divisions on the long screw, screw drive, make up or down motion water box, box static pressure in the water by mouth with degrees in blocks, in degrees must block in the middle of the degrees of plate and the plates move to indicate the water displacement of the height of the tray. 2. Level observation section - In the observation tube with a level head, with observations by dynamic pressure pipe pressure change inside the liquid surface. 3. Mirror part - By a mirror fixed to the shell on the mirror, the mirror surface reflection was used to observe the level in the cylinder head contact with the liquid surface, the level of the head and the reflection of pointed following said that the 'basis of micro pressure meter reading adjustment '4. Shell part - By the shell and the cross arm support long screw, bubble and adjusting screw on the shell is equipped with level, to adjust the micromanometer screw and vertical dynamic pressure tube.