1, Class A measuring instruments include: first-class flat crystal, zero-class knife edge ruler, level meter, square ruler, dial indicator, dial indicator, autocollimator, vertical optical instrument, etc.
2. Class B measuring instruments include calipers, micrometer, dial indicator, dial indicator, level gauge, square ruler, feeler gauge, level gauge, theodolite, welding inspection ruler, ultrasonic thickness gauge, and tape measure over 5M.
There are thermometer, pressure gauge, dynamometer, tachometer, balance, voltmeter, ammeter, megger, electric power meter, bridge, resistance box, ammeter, multimeter, standard resistance box, calibration signal generator, ultrasonic flaw detector, spectrophotometer, etc.
3. Class C includes steel straightedge, bending ruler and steel tape measure below 5M.
Extended data
According to the classification of measuring purposes, measuring instruments can also be divided into the following three categories: standard measuring instruments, standard measuring instruments and working measuring instruments.
1. Benchmark measuring instruments: the measurement benchmark is the measurement standard with the highest measurement characteristics in the contemporary era, which is designated or recognized without referring to other standards of the same magnitude.
2. Standard measuring instruments: A measuring standard refers to a physical measuring tool that defines a unit to be saved or copied or one or more quantities as a reference. Measuring instruments, reference materials or measuring systems.
3. Ordinary measuring instruments: Ordinary measuring instruments refer to measuring instruments that are used in general daily work and can obtain certain quantitative measurement results.
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