1Pair Transistor A1943 C5200 Power Amplifier 2SC5200 2SA1943 Transistor 2SC5200

Measuring instruments are the third party standards required for measuring in order to obtain some attribute values of the target. Measuring instruments generally have scales, volumes and other units.
Scholars and navigators know very well that if the position of celestial bodies can be accurately measured on the sea, then sailors can know their latitude with certainty. To do this, we need precise measuring instruments.
Ptolemy once described the astrolabe (also called the astrometer). The larger ones are used in observatories and the smaller ones are used on ships. The use of the astrolabe requires the cooperation of three people - one holds the thumb ring on the astrolabe, one aims, and the other reads the results on the dial. When the ship shakes violently, the results are naturally not very accurate. Whenever possible, sailors will go ashore to survey.
Ancient astronomers used a cross ruler to measure the latitude of stars. Later sailors also used it in navigation. The instrument consists of a ruler and a cross ruler, with the lower end of the cross ruler placed in a horizontal position. While observing the celestial body along the ruler, slide the cross ruler until it touches the object (sun or star) in your view, and then read the degree on the ruler. This instrument can be operated by only one person.
Both the astrolabe and the cross ruler require the observer to observe the sun directly. In sunny days, too strong light will make observation impossible. In order to solve this problem, England captain and navigator John Davis invented the back ruler. It is made of a ruler and a sliding crossbar. When observing, the observer first turns his back to the sun, and then slides the crossbar until it casts a shadow in the small disk in front of him. In this way, the observer can observe the horizon.
John Davis also invented the quadrant with the help of Edward Wright, a mathematician from Cambridge. There is an eyepiece on the crossbar of this instrument, through which the observer can observe the horizon and the reflected sun.
Pierre Burger, a hydro geographer in Kloicik, made further improvements to the object limiter. The improved quadrant enables the observer to see the sun setting on the horizon through the eyepiece.
John Hadley in England invented the octave, which was first tried in 1732. It consists of a reflecting and an alcohol level. This instrument is more accurate than any other instrument used at sea before.
Instrument index
The basic contents of the concept of measuring instrument include: precision, error, measuring standard equipment, length measurement, angle measurement, shape measurement, and traditional optical instruments. Application in precision measurement, etc.
There are two types of measuring instruments: contact test and optical test (most used) contact test: general measuring tools and 3D measuring tools (CMM is also called 3D) CMM is also called 3D, which can measure many complex spatial dimensions, such as molds and automobile products.