(1) Before use, observe whether the dividing value, measuring range and zero line of the scale are worn.
(2) Correctly place the scale: the zero scale line is aimed at one end of the measured length, and the side with the scale line should be close to the measured object and parallel to the measured length, and cannot be skewed.
(3) When reading, the line of sight should be facing the scale line.
(4) The recorded data should have numbers and units, and it is meaningless to record without units; Estimate to read the next bit of the minimum scale.
(5) When measuring the values in the figure below, it should be noted that the starting point is not from zero, which is a common test question.
Measurement method of length
1. Common length measuring tools:
Unified scale
Specifically: ruler, tape measure, vernier caliper, micrometer (screw micrometer) and so on.
2. Methods of measuring length with scales: observation, estimation, selection, release, adjustment, measurement, reading, recording and calculation.
(1) observation: observation
(1) Where is its zero scale line and is it worn?
(2) What is its scope?
(3) what is its division value?
note:
① The dividing value is different from the unit marked on the scale.
② The division value is not necessarily the unit value. (It can be 0. 1 cm or 0.5 cm)
(3) said the dividing value, there should be a number, such as 1cm or 0.5cm.
Brief introduction and classification of length measuring tools
Brief introduction of length measuring tools:
Length measuring tool refers to a tool that compares the measured length with the known length and obtains the measurement result, which is called measuring tool for short. Length measuring tools include gauges, measuring tools and gauges.
Classification of measuring tools:
Ruler is a very common tool for measuring length. Almost every pupil has one, which is usually used to measure short distances or draw straight lines. ?
Triangle is one of the main tools for learning mathematics and measuring angles. Each set of triangles consists of two special right-angled triangles. It can be used for short-distance measurement and other functions such as drawing right angles.
Steel ruler: made of metal and other materials, ranging from 3 to 5 meters, has certain flexibility and is used for decoration. , but also for daily life.
Tape measure: Soft cloth, mainly used for construction site measurement.
The latter two measuring tools, commonly known as meter ruler, take "meter" as the main unit of measurement.
Invar baseline ruler: used for traditional precision ranging.
Vernier caliper is a high-precision measuring tool. It can directly measure the outer diameter, inner diameter, length, width, height and depth of the workpiece.
The reading of vernier caliper consists of ruler and vernier.
Spiral micrometer is a more accurate length measuring tool than vernier caliper. It can be used to measure the length as accurate as 0.0 1mm, and the measuring range is several centimeters.