Experiment Measurement - BG 1212 Download实验测量BG 1212下载.docVIP

ASSUMPTION UNIVERSITY Faculty of Engineering Physics Laboratory Name:_________________________________________ Code:_________________ Sec:______ 1. Experiment : Vernier calipers 2. Objective : To determine the dimensions of given small objects by using vernier calipers. 3. Apparatus : Vernier calipers, rectangular object, cylindrical object and electronic digital scale. 4. Theory : The Vernier Calipers is a precision instrument that can be used to measure internal and external dimensions of small objects extremely accurately. The vernier calipers enable us to obtain an accurate result up to the second decimal place in millimeter. (e.g. 0.05 mm and 0.02 mm) The main scale and vernier scale are marked on the instrument. The sum of above two scale measurements and zero error reading (or) zero error correction of the vernier caliper is the required dimension of the measurement of the object To use the vernier scale, Least count (LC) and zero error reading (or) zero error correction of the vernier caliper must be checked and recorded before measuring the object. Least Count of vernier calipers Least Count (LC) for an instrument is the minimum measurement that can be made accurately by a measuring device. A measuring instrument cannot measure anything whose dimensions are less than the magnitude of least count. The instrument will have more precise measurement if the magnitude of least count is smaller value. Last Count of vernier calipers is the minimum measurement by vernier calipers. The magnitude of least count of vernier calipers is depending on the nature of the scale (mm, cm, inch, etc.) and the number of division on vernier scale. The least count of vernier calipers can be calculated by the difference of one vernier scale division and main scale division(s), which is nearest to the one vernier division