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An instrument for measuring and recording roughness of the surface over which it travels.



in metalworking, an instrument for measuring surface irregularities and displaying the results in the form of a curve characterizing the waviness and roughness of the surface. The curve is subjected to graphic analysis.

A profilograph uses a sensing stylus that moves perpendicularly to the surface being measured; oscillations from the stylus are optically or electrically converted into signals that are recorded on photosensitive film or paper. The first profilographs appeared in the late 1930’s and were opticomechanical devices for recording a signal on motion-picture or still photographic film. In modern profilographs, the oscillation of the stylus is usually converted into voltage oscillations using induction, capacitance, and piezoelectric converters.

Profilographs consist of three units: (1) a bedplate, with a measurement stand and a drive mechanism, (2) an electronics module, and (3) a recording device. A diamond stylus with a radius of curvature of 2–12 microns is mounted on a sensor. The static pressure of the stylus on the surface being measured varies from 1 to 20 millinewtons(l millinewton = 0.1 gram-force); the pressure under dynamic conditions varies from 0.06 to 1.2 millinewtons for 1 micron of axial displacement of the stylus. The recording of the profile using instruments with electric conversion of the signal is most often done on metal-coated paper. For ease of interpretation, the curve is traced on an enlarged scale. The recording of the measured heights of the irregularities may be amplified by a factor of 400 to 200,000. Horizontal amplification up to a factor of 100,000 is achieved as a result of the rapid motion of the paper relative to the rate of displacement of the stylus.

The error in the vertical amplification for different types of instruments ranges from ±5 to ±10 percent, and in the horizontal amplification the error is no more than ± 10 percent. Profilographs are usually manufactured in units that include a profile meter and are equipped with attachments that permit profiles of parts with various shapes to be measured.


Vzaimozameniaemost’ i tekhnicheskie izmereniia v mashinostroenii. Moscow, 1972.


References in periodicals archive ?
A laser-based profilograph of the Mahr company was used.
Based on profilograph records of concrete pavements in California, Hveem (1951) concluded that slab curling was due to the combined effect of temperature and moisture, both of which change non-uniformly through the depth of the slab.
The government seeks to establish a distinction between inapplicability and the lack of a requirement, but any such distinction is too attenuated to be significant; in its claim to the Contracting Officer, ACE manifestly was challenging the need for profilograph testing.
The profilograph is roughly composed of a stylus, a data acquisition system, and a traveling mechanism.
The relative position of the replicated marks is detected by the profilograph and local shrinkage is calculated.
1 km section as measured with a California-type profilograph, a wheeled instrument for measuring smoothness by amplification of any variations from the plane.
Unfortunately, because of the technical limitations of the profilograph equipment and PI computation procedures, the adequacy of PI5-mm in characterizing roughness and having it relate to user response has come into question.
To overcome the limitations of a short straightedge and to better measure the roughness the motorist feels, devices with names like profilometer and profilograph were developed.
By maintaining the optimal asphalt mix temperature and consistency; using a steady, non-stop paving process; having a consistent methodology; making appropriate onsite equipment modifications; executing well-planned roller strategies; and using profilographs and profilometers for measuring results, a contractor can construct and deliver a better product.