The tool for measuring the force is called a dynamometer. The spring dynamometer is an important measurement tool for measuring the force in the laboratory, and it is also an important test point for middle-test questions. Here's a discussion with the students about the use of spring dynamometers and readings:
First, principle and structure
The greater the tension the spring receives, the longer the spring stretches. Within the limit of elasticity, the amount of spring elongation is directly proportional to the tensile force it receives. The spring dynamometer is designed on the basis of this principle. Spring dynamometers are composed of springs, hands, scale plates, hooks, rings and shells.
Second, use method
(1) When using spring dynamometer, it is necessary to first see the range and the force to be measured cannot exceed its range. Because the spring has a certain elastic limit, measurement beyond this limit is inaccurate, and it may damage the dynamometer. (2) Before the measurement, it is necessary to look at the index value of the spring dynamometer so that the reading can be measured. (3) Before measuring, check whether the pointer is on the zero scale line. If you do not refer to the zero scale line, adjust it so that the pointer points to the zero scale line. (4) Before use, gently pull the hook of the spring dynamometer back and forth to prevent the pointer from getting stuck, which will cause a large error in the measurement. (5) During the measurement, the force of the pull spring dynamometer hook should be parallel to the dynamometer housing to avoid distortion and friction, and the measurement error due to friction should be minimized. (6) Wait until the reading is stable before reading. The reading should be perpendicular to the scale surface.
The last thing to note is that when using a spring-loaded dynamometer, use a hook-and-pull method to pull the object upwards. Because it is designed according to this method, the error using other methods is relatively large. Third, reading
The reading of the spring dynamometer is relatively simple. It is necessary to figure out the range and division value of the spring dynamometer first, and then read out the measured force according to the position of the pointer (because the position of the end of the pointer must refer). . Fourth, the use of spring dynamometer prone to problems
(1) Measure the force beyond the measuring range with a dynamometer; (2) Measure without zero adjustment; (3) Pull the spring back and forth without using a hand, and measure with a dynamometer whose finger is stuck; (4) Tension measured with The dynamometer shell is not parallel; (5) the reading is not stable; (6) the sight line is not perpendicular to the surface of the scale plate; (7) hold the hook in the hand and hang the object on the ring to measure.
Disposable Paper Plate,Disposable Paper Tableware,Disposable Food Paper Plate,Disposable Soup Bowl
Shandong Shengquan New Materials Co., Ltd. , https://www.sqnewmaterials.com