The wooden ruler of the Ministry of Industry is mainly used to check whether the planed boards, purlins and structures are vertical and whether the edges are at right angles.
In the Qing Dynasty, the construction ruler used in construction projects was stipulated as the standard ruler (1 construction ruler is equal to 0.32m).
1928, the construction ruler is parallel to the metric system, which is determined by the meter, but it failed. Since then, various measurement laws and regulations have been promulgated in succession, trying to unify the measurement system. Until the founding of People's Republic of China (PRC), people were still using all kinds of old-fashioned instruments.
Types of ancient rulers
1. Give them different names of rulers according to different purposes. For example, it is used in comparative musicology, called "ruler of rhythm", or ruler for short; Woodworking is called "Woodworking Ruler", also called Lu Banchi. The building is called "building ruler"; Garment makers use a "tailor's ruler", also known as a tailor's ruler, which is referred to as a cutting ruler.
2. Named after the standards for determining the length of rulers in past dynasties, such as millet ruler (ancient arrangement 100 millet, taking its length as the standard of one foot, called "millet ruler", including horizontal millet ruler, vertical millet ruler, oblique millet ruler, etc. ) and money ruler (including cargo spring ruler, Kaiyuan money ruler, banknote ruler, etc. ).
3. According to the different shapes of the scale, it can be divided into ruler, ruler and tape measure. When the weighing system was redefined in the late Qing Dynasty, it was divided into five types: building ruler, rectangular ruler, folding ruler, chain ruler and tape measure.