Abstract: A measuring instrument comprises a column (10) on which is mounted a carriage (11) with a drive cursor (12) and a measuring cursor (20) sliding on the drive cursor (12) and carrying a measuring contact (24) and a measuring device (40). A measuring force device (25) is arranged between the two cursors and determines, thanks to a lever (26) a rest position and two measuring positions vertically upwardly or downwardly offset or corresponding to a predetermined measuring force on the member to be measured. A motor (15) displaces the drive cursor (12) and the position detector (36) permits measuring the relative position between the two cursors. A control unit (35) controls the speed and direction of rotation of the motor (15) as a function either of the signals (44) received from the position detector (36) or from two external contacts (42, 43).

Abstract: In a "half-turn" type two-disc tap, the two discs are superposed and in contact to adjust the flow rate of a liquid. Each disc has first and second openings situated on respective sides of a predetermined diameter of the disc. The first opening is situated in the central part of the disc and the second opening is situated at the periphery of the disc so that in the closed position of the tap is openings of each disc are separated from the openings of the other disc and in the maximum open position of the tap the first and second openings are respectively and conjointly superposed over an angle just less than 360.degree..