Instructions for checking mechanical and electronic caliper devices for absolute measurement.
This instruction follows approximately the checking instructions of the German standard DIN 878 for dial devices and the checking instructions for caliper devices according to VDI/VDE/DGQ 2618, page 13. The devices are referred to as devices with absolute measurement and adjustable zero point.
Terms of length test techniques see DIN 2257 part 1 and part 2.
2.1 Range of application AwB
The range of application AwB of a device corresponds to the sum of regulating range and measuring range.
2.2 Measuring range Meb
The measuring range of a device represents the range of measuring values in which given error limits must not be exceeded.
2.3 Numerical interval Zw
The numerical interval of a numerical scale is the modification of the value of a measured variable that causes the modification of the indication by one interval. The numerical interval corresponds to the scale interval of a line scale and is indicated in the unity of the measured variable.
2.4 Scale interval Skw
The scale interval Skw is indicated on the scale, f.e. 0.01 mm. It corresponds to the measuring value between two scale graduation marks.
2.5 Deviation in the measuring range fM
The deviation m the measuring range (range of deviation) fM represents the distance of ordinates between the highest and the lowest position in the deviation diagram when the movable caliper arm closes. The tolerance field for fM is symmetrically positioned to the zero line and is indicated in fMzul.
2.6 Deviation in the partial measuring range ft
The deviation in the partial measuring range (range of deviation) ft represents the distance of ordinates between the highest and the lowest position in the deviation diagram, measured for a partial measuring range when the movable caliper arm closes. The tolerance field for ft is symmetrically positioned to the zero line and is indicated in fmzul. The deviation in the partial measuring range ft can only be determined by using electronic testing methods during the preparation of certificates of quality.
2.7 Repeatability fw
The repeatability fw is a characteristic value for deviations of the measured variable within the measuring range in the same motion direction of the movable caliper arm (usually n is 5).