Abstract: A pressure gauge has a base which is provided with a slot, and a sliding block located in the slot such that the sliding block is pushed to displace by a piston rod which is in turn pushed by the air pressure to be measured. The sliding block is provided with a plurality of teeth for actuating a rotary shaft and a hand fastened at one end thereof with the rotary shaft. The hand is actuated to turn to point at an air pressure reading. The base is provided with a threaded hole, an adjusting screw engaged with the threaded hole, and a spring which is engaged at one end thereof with the sliding block and at other end thereof with the adjusting screw. The pressure gauge is calibrated by adjusting the position of the adjusting screw in the threaded hole.

Abstract: An ink droplet ejecting device includes first and second grooves formed on a piezoelectric ceramic plate. The positions of the first and second grooves are offset by a half pitch and are formed by cutting. A cover plate closes openings of the grooves at one side of the piezoelectric ceramic plate. The first grooves become gradually shallower toward one end surface of the piezoelectric ceramic plate to form flat surface portions so that the second grooves do not intercommunicate with a manifold of the cover plate. Further, first metal electrodes are formed on inner surfaces of the first grooves, and second and third metal electrodes are simultaneously formed on inner surfaces of the second grooves on the whole surface of the piezoelectric ceramic plate where the second grooves are formed.