A method of determining whether a structure such as a bridge has been severely damaged by an earthquake or other disturbance such as a flood. The method is designed to be carried out by unsophisticated persons immediately after such disturbance so that unnecessary delays will not be caused by the closing of bridges and the like which are not severely damaged. The method involves affixing a target to one portion of the structural member such as a span and affixing a pointer on another structural member such as a column. Preferably the target and pointer are positioned in such a way that a safe or unsafe determination can be easily made by the viewer.

An apparatus for aligning adjacent surfaces for coplanarity and angle is described. The apparatus comprises a base plate, a plurality of support legs coupled to the base plate, a plurality of depth gauges coupled to the base plate, an angle coupled to the base plate, and leveling means coupled to an inclined surface. The inclined surface of the angle plate slopes towards the plurality of depth gauges. The inclined surface has a predetermined angle. A method for aligning first and second adjacent surfaces for coplanarity and relative angle is also described. The alignment apparatus is placed on a flat surface. The apparatus is calibrated so that all of the plurality of depth gauges read a first value. The apparatus is placed on the first and second adjacent process modules such that the support legs rest on the first adjacent process module and the plurality of depth gauges rest on the second adjacent process module. The first and second process modules are aligned such that the plurality of depth gauges read the first value. The first and second process modules are aligned until the leveling means indicates level.

A ball bar gauge for evaluating the performance of coordinate measuring machines is disclosed. The gauge consists of a rigid bar having a magnetic chuck at each end. Each magnetic chuck consists of a permanent magnet and six magnetic pole pieces surrounded by a non-magnetic housing. The bar is used with two precision tooling balls which are placed in the chucks at each end of the rod. In each chuck three of the pole pieces are slightly longer than the other three pole pieces to provide a stable three-point contact seat for the associated ball.

The specification discloses a device for detecting movement of two portions of a structure relative one another. The device comprises a first disc defining a radial scale and fixedly securable to the first portion of the structure and a second disc fixedly securable to the second portion of the structure. A telescoping linear scale extends between and is pivotally secured to the center of the radial scale and to the second disc. Consequently, the angular orientation of the telescoping scale with respect to the first disc is displayed on the radial scale; and the distance between the disc members is displayed on the linear scale, providing a measurement of movement between the structural portions. Also disclosed is a method of detecting structure movement comprising securing the device to the two portions of the structure and monitoring subsequent readings displayed on the radial and linear scales.

The invention relates to a device for displacement of blocks, with a view to comparison of their dimensions by means of a measuring apparatus, which device includes a support, referred to as the measuring table, which defines a supporting and sliding plane for the blocks, a piece, referred to as the template, situated above the measuring table and bearing stops disposed in order to maintain the blocks in a predetermined position and orientation relative to the measuring apparatus, by cooperating with the lateral faces of the blocks, while preserving their free support on the measuring table, and is carried by a guide device along at least one axis parallel to the pressing plane, this device being characterized in that the template is made up of two separate parts which can be displaced separately from one another.