Not only on production, but also in life quite often there is a need to learn the sizes of small details. To measure diameter of a drill or section of a wire, to determine the amount of internal dredging in preparation, it is the most convenient to use a caliper. This tool is quite simple in use though work with it and demands some skill.
Caliper device
The measuring ruler is extremely simple in application, but it is possible to measure by it objects only with very low degree of accuracy. If statements of the problem place greater demands on results of measurements, it is the best of all to use a special type of the control and measuring tool which carries the name of a caliper.
This device gives the possibility to determine the internal and external dimensions of objects and also the depth of small holes.
The traditional caliper consists of the extended bar supplied with motionless sponges. On a bar the frame having mobile elements and the lock screw moves. On a flat surface of a bar there are cut-offs reproducing a scale with the division price in one millimeter. Length of a standard scale, as a rule, equals 150 mm though it is possible to meet also more impressive models. On a mobile part of the tool it is possible to see a scale of auxiliary appointment which is called the nonius.
How to use a caliper
To take measurements with use of a usual caliper, it is necessary to prepare the tool. For this purpose it is required to part caliper sponges on sufficient distance, and then to densely press out them the measured object, for example, a drill or a metal rod. It is not necessary to make at the same time excessive effort not to damage the tool. Now it is necessary to look at the very first (left) tag which is available near the lower scale to find out on what division it was established. For example, if the tag was located between zero and unit, it means that the subject has the size less than a centimeter. The following step is in finding out with what of divisions of the top scale the tag coincides. If it is opposite to division 7, then the size of the measured object is 7 mm. By means of a caliper it is possible to measure as well the tenth shares of millimeter. If the lower tag was established between figures 7 and 8, it is necessary to watch which of tags in accuracy coincides with risky on the top scale, making with it the uniform line. The fifth tag coincided? It demonstrates to what to the received result is required to be added half-millimeter.
The number of additional labels on the lower scale can be set to 10 or 20, depending upon the accuracy class of the caliper.
To measure internal diameter by a caliper also not too difficult. For this purpose the tool has two slightly pointed sponges in the top part. They need to be inserted between the internal surfaces of dredging or a pipe, and then to move apart against the stop. All other measuring actions at the same time will be the same that are described above for external measurements.