Measuring the length of an object

Precautions when using a scale to measure length are as follows:

(1) Observe the scale's division value, range, and zero mark before use to make sure it is not worn out.

(2) the correct placement of the scale: zero line aligned with the end of the length to be measured, the side of the scale should be close to the object to be measured and parallel to the length to be measured, can not be skewed.

(3) When reading, the line of sight should be right on the scale.

(4) Record data with numbers and units, without units is meaningless; to estimate the reading to the next smallest scale.

(5) Measure the values in the chart below, and note that the starting point does not start at zero; this is a common class of test questions.

Measurement of length

1. commonly used length measurement tools:

Uniformly referred to as: scale

Specific: ruler, tape measure, vernier calipers, micrometer (spiral micrometer), etc.

2. use of the scale to measure the length of the method: view, estimate, choose, put, adjust, measure, read, record, calculate.

(1) observation: observation

① where is its zero scale line, whether it is worn?

② What is its range?

③ What is its graduated value?

Note:

①The divisional value is not the same thing as the unit marked on the scale.

② The index value is not necessarily exactly the value of a unit. (can make 0.1cm or 0.5cm)

3 expression of the index value should be with numbers: such as 1cm or 0.5cm

Length measurement tools and classification

Length measurement tools:

Length measurement tools is the length of the length of the measured length of the comparison with the known length of the measured results of the tool, referred to as the measuring tool The tool, referred to as the measuring tool. Length measuring tools include gages, gauges and measuring instruments.

Measuring tools:

The straightedge is a very common tool for measuring length, and almost every elementary school student has one, usually used to measure short distances or to draw straight lines.

Triangle boards are one of the main tools for learning math and measuring angles. Each pair of trigonometry boards consists of two special right triangles. It can be used to measure short distances and for other purposes such as drawing right angles.

Steel ruler: made of metal and other materials, ranging from 3-5 meters, a certain degree can be bent, used for decoration, etc., but also used in daily life.

Tape measure: soft cloth material, mainly used for construction site measurements.

The last two measuring tools, commonly known as meters, use "meter" as the main unit of measurement.

Invariable Linear Ruler: Used when making traditional precision distance measurements.

Vernier calipers are a highly accurate gauge. It can directly measure the outer diameter, inner diameter, length, width, height and depth of the workpiece.

Vernier caliper reading by the ruler body and vernier two parts.

The spiral micrometer is a more precise tool for measuring length than the vernier caliper, with which the length can be measured as accurately as 0.01mm, with a measuring range of several centimeters.