in-dash tachometer

• 2022-04-08

The tachometer is always set in-dash . According to the specific situation of the measured rotating object, select the appropriate connector, such as rubber joint, etc. Use the rotary range switch to select the appropriate range (turn the scale value to the same dial at the same level). If the unknown quantity is measured, the maximum range shall be selected for rough measurement, and then the range shall be determined. Make the test shaft of the tachometer contact with the tested shaft, keep a certain pressure and operate synchronously, and keep it on the same center line. After the pointer of the tachometer is stable, the speed of the measured rotating object can be measured. The speed is equal to the ratio of the upper range selected by the range switch to the full range of the reading disk multiplied by the reading of the reading disk. When measuring the linear speed, the runner test head shall be used. The measured reading is converted according to the following formula: linear speed (M / min) = (upper range selected by range switch / full range of reading disk) * Tachometer * Circumference of runner test head.

During the test, the pointer deflection of the tachometer has nothing to do with the rotation direction of the tested shaft. The center of the tested shaft of the tachometer and the tested shaft shall be on the same horizontal line, and the meter head shall bear the rotating shaft. During measurement, the hand should be stable and the force should be appropriate. Not only should the top be too loose, resulting in sliding loss of rotation and error, but also should the top be too tight and damaging the tachometer, subject to no relative sliding between the tachometer shaft and the measured shaft. When the tachometer is used to measure the rotational speed of the position, the maximum range shall be used for rough measurement first, and then the appropriate range shall be selected. It is not allowed to measure high speed with low gear to avoid loss of meter. The reading dial scale of mechanical centrifugal tachometer is uneven and usually has two columns of scales. If gears I, III and V are used for measurement, the scale value of the outer ring shall be multiplied by "10", "100" and "1000" respectively; If gear II and gear IV are used for measurement, the scale value of the inner ring shall be multiplied by "10" and "100" respectively. The tachometer shall be filled with lubricating oil (watch oil) before use, which can be injected from the oil filling hole of the housing and range switch. After the instrument is used, it shall be wiped clean and placed in a place where the sun cannot directly shine, away from the heat source, and pay attention to moisture and corrosion prevention.