electronic neigungsmesser display the tendency about the length of the instrument

摘要

PCT No. PCT/US93/07434 Sec. 371 Date Feb. 13, 1995 Sec. 102(e) Date Feb. 13, 1995 PCT Filed Aug. 11, 1993 PCT Pub. No. WO94/04888 PCT Pub. Date Mar. 3, 1994An electronic level includes a visual scale (similar to a ruler scale) having a number of parallel line segments. The inclination of the device is shown by illuminating various of the scale line segments on either side of a central line. When the device is at a null (typically level or plumb) only the central scale line is illuminated, indicating the inclination away from the null. Each scale line segment indicates a fraction of an inch of inclination per e.g. two feet of horizontal distance (the two feet being the level length in one version) which conforms to the normal use of such levels by building tradesmen. The level is calibrated by taking two readings with the level rotated 180 DEG between readings. The readings are averaged and negative feedback is provided to the level sensor itself to null out any system mechanical or electrical offsets.