Digital vernier caliper devices are hand tools used for precision calibrations of numerous technologies. Such technologies might include scientific instruments, machinists' measuring tools, and navigation tools like sextants. Many industries rely on equipment that must be accurately calibrated to sometimes minute tolerances. Based on a traditional manual caliper design, modern digital calipers take the guesswork out of alignments with a sliding scale and display them conveniently on a digital readout. Digital calipers usually resemble a slide rule, with a fixed jaw on the end and another sliding jaw with its own scale corresponding to the fixed ruler scale.
Traditional manual calipers were limited by the visual acuity of the operator. A special scale was developed by French mathematician Pierre Vernier in 1631; it was designed to improve accuracy of eye-sighted calibrations. Instead of holding a scale up to an object, this device is placed in or around the object while its two scales are compared using the slightly more user-friendly process of aligning lines between scales. The sliding scale is constructed as a constant fraction of the main scale in order to make calculations easier.
It's generally more accurate — and easier — for people to use this device to judge whether lines match up than using some other means of visual measurement. This permits more precise calibration, with intuitive recognition of alignment and misalignment. This process is known as vernier acuity.
On digital vernier caliper equipment, physical distances are translated into electronic information through capacitance. Commonly relying on battery power, digital vernier caliper units are intuitive to operate and consistent in performance. These devices are employed in numerous contexts, including manufacturing, engineering,and metrology, or scientific measurement.
Contemporary digital vernier caliper products enhance the capabilities of the caliper with additional digital functions. Often able to switch between imperial or metric units, calipers may feature durable equipment of high material quality that could provide accuracy to within the micrometer range. These are units put in hundredths of a millimeter or thousandths of an inch.
Typically handheld devices used to measure distances, digital vernier caliper tools may measure internal, external, or height dimensions. These might include depth or step measurements. To operate, the user typically turns on the caliper, closes the jaws and resets it with a zero button.
The jaws are then opened to the inside or outside of an object to be measured and locked into place. A digital readout will display the measurement in the desired units. Many such calipers possess a set of outside jaws, inside jaws, and a depth probe.