Manual crackmeters

Manual crackmeters are used for the measurement and of cracks on surfaces having vertical and/or horizontal movements, failures or adjustments of floors on masonry, pillars, etc. They consist of two overlapped moving plates: the upper plate is engraved with a grating while the lower plate is  calibrated in millimeters. The measurement of movement can be detected in fractions of millimeter, and it is marked by the displacement of the plate with grating from the underlying millimeter plate, starting from 0.