Digital Caliper – What is the least count of digital caliper? Calipers are mechanical instrument with two or more curved handles that enable the person holding them to slide their fingers along the scales to determine the measurement. The handles move with the resolution of the machine and so can be either curved to suit the needs of the user, straight or curved to match the machine’s resolution. In this way we can say that a Caliper is a multi-purpose device.
Most plastic-based digital calipers are used for very small measurements, like in cosmetic application where the accuracy is critical. However, for some uses plastic is simply too soft and so plastic is used in a couple of other inexpensive digital calipers. It is less resistant to damage and usually produces a slightly inaccurate result when measured at small measurements. For larger measurements it is practically impossible to get a perfect result, no matter how hard you try, so the measurement is considered to be an average. While generally depicted with the large main jaws used to read the outside dimension of an object, modern calipers have also added three additional ways to carry out the measurement.
A digital caliper can be used to make measurements of either conductors fluids or solids. A dial caliper is used for liquids and one can measure conductivity, Specific Gravity and Temperature. A motorized dial caliper is attached to a motorized arm that enables the user to work inside a tight enclosure or small space. This type of caliper is ideal for making measurements over large surfaces, such as a circuit board.
The external measurements are usually made with a pair of externally adjustable grips. These grips ensure accuracy by holding the piece of material in position while enabling the user to move it around easily. Some digital calipers provide two separate sets of jaws, which allows the user to read either the conductivity or specific gravity of the sample. This feature is ideal for taking surface measurements.
In order to obtain the most accurate result, digital calipers must be calibrated. Calibration ensures that the device measures zero degrees all the way through. Zero degrees indicate that the sample is at rest and the measurement is on an unchanging basis. Most devices provide a range of zero values along with an accumulator to determine the minimum and maximum values. The most common method of calibration is using a spring that holds constant value and thus adjusts as the sample changes.
Digital calipers have revolutionized the measurement of material properties, such as thermal conductivity, hardness, pliability and elastic modulus. These devices are ideal for applications requiring uniform results regardless of the orientation in which the sample is held. They can measure electrical resistance as well as mechanical stiffness. There are two general types of digital caliper: dial calipers and surface calipers. Dial calipers require manual calibration, whereas surface calipers have built-in self calibrating features.
Most digital calipers use a single unit system, which consists of a dial. A variable level is provided on the dial so that adjustments can be made either in terms of increments of degrees or in inches. The level can also be set on the unit itself. This feature makes digital calipers suitable for making measurements over short distances.
Digital calipers are available in different sizes and using different technologies. Most modern devices are equipped with automatic shut-off mechanism that automatically shuts off the power when the distance covered by the device becomes too small. The power consumed by the device used for making the measurement is considerably less than that required for older models. Newer models allow for automatic power shutdown when the measurement reaches a particular threshold.