The determination of the slope of the stairs should take into account the comfort of walking, the efficiency of climbing and the state of space. The line connecting each point of the step leading edge of the step is called the slope line. The angle between the slope line and the horizontal plane is the slope of the stairs (the tangent of this angle is called the gradient of the stairs). The slope of the indoor staircase is generally 20 degrees - 45 degrees, and the best slope is about 30 degrees. Stairs with special features require different slopes. For example, the slope of the ladder is above 60 degrees, the special stairs are generally 45 degrees -60 degrees, the slopes of the indoor and outdoor steps are 14 degrees -27 degrees, and the slope of the slope is usually below 15 degrees. Generally speaking, in places where the flow of people is large, the safety standards are high, or the area is relatively abundant, the stairs should be gentle. The auxiliary stairs are only used by a few people or used infrequently. The slope can be steeper, but it is better not to exceed 38. degree. Portable spectrophotometer,45/0 spectrophotometer,Hardware spectrophotometer CHNSpec Technology (Zhejiang)Co.,Ltd , http://www.chnspec2013.com