传感器原理传感器原理 (7).ppt

Principle of Sensors传感器原理电阻应变式传感器Resistance Strain-Gage Sensors 3.1.3、应变片的结构与分类Structure and classification of strain gauges 应变片的结构与分类应变片的结构与分类应变片的结构与分类应变片的结构与分类Structure and classification of strain gauges Structure and classification of strain gauges 组成：敏感栅敏感栅敏感栅敏感栅1 1、基底基底基底基底2 2、盖片盖片盖片盖片3 3、引线引线引线引线4 4、粘结剂粘结剂粘结剂粘结剂5 5Composition:Sensitive Grid 1,Substrate 2,Cover 3,Lead 4,Sensitive Grid 1,Substrate 2,Cover 3,Lead 4,Binder 5 Binder 5 作用作用作用作用：实现应变电阻转换的敏感元件应变片测得的应变大小是应变片栅长和栅宽所在面积内的平均轴向应变量Function:Function:Sensitive element to realize strain-resistance conversion The strain measured by strain gauge is the average axial strain in the area where the grid length and width of strain gauge are located.Grid lengthGate width敏感栅敏感栅敏感栅敏感栅Sensitive grating Sensitive grating 对敏感栅的材料的要求对敏感栅的材料的要求对敏感栅的材料的要求对敏感栅的材料的要求：应变灵敏系数大，并在所测应变范围内保持为常数；电阻率高而稳定，以便于制造小栅长的应变片；电阻温度系数要小；抗氧化能力高，耐腐蚀性能强；在工作温度范围内能保持足够的抗拉强度；加工性能良好,易于拉制成丝或轧压成箔材；易于焊接，对引线材料的热电势小。

对应变片要求必须根据实际使用情况，合理选择Requirements for sensitive grid materials:Requirements for sensitive grid materials:The strain sensitivity coefficient is large and keeps constant within the measured strain range;The resistivity is high and stable,so as to make strain gauges with small grid length;The temperature coefficient of resistance should be small;High oxidation resistance and strong corrosion resistance;It can maintain enough tensile strength within the working temperature range;Good processing performance,easy to draw into wire or roll into foil;It is easy to weld and has small thermoelectric potential to lead materials.The strain gauge must be selected reasonably according to the actual use.基底和盖片基底和盖片基底和盖片基底和盖片Substrate and cover sheet Substrate and cover sheet 作用作用作用作用：基底保持敏感栅、引线的几何形状和相对位置，盖片保护敏感栅。

Function:Function:The substrate maintains the geometry and relative position of the sensitive grid and lead wires,and the cover sheet protects the sensitive grid.引线引线引线引线 LeadsLeads材料要求材料要求材料要求材料要求：电阻率低、电阻温度系数小、抗氧化性能好、易于焊接Material requirementsMaterial requirements:Low resistivity,small temperature coefficient of resistance,good oxidation resistance and easy welding.粘结剂粘结剂粘结剂粘结剂 BinderBinder作用：将敏感栅固定于基底上，并将盖片与基底粘贴在一起将应变片基底粘贴在构件表面某个方向和位置上Function:Fix the sensitive grid on the substrate,and paste the cover sheet with the substrate.Stick the strain gauge substrate in a certain direction and position on the surface of the component.应变片的类型应变片的类型应变片的类型应变片的类型Type of strain gaugeType of strain gaugeDivided by material Divided by material Body type-silk type,foil type Metal typeMetal type:film type Semiconductor typeSemiconductor type:body type,thin film type,diffusion type,epitaxial type and PN junction type Divided by structureDivided by structure:single piece,double piece and special shape Divided by the using environmentDivided by the using environment:high temperature,low temperature,high pressure,magnetic field and underwater 按材料分为按材料分为按材料分为按材料分为 体型 丝式、箔式 薄膜型 半导体式半导体式半导体式半导体式：体型、薄膜型、扩散型、外延型、PN结型 按结构分按结构分按结构分按结构分：单片、双片、特殊形状 按使用环境按使用环境按使用环境按使用环境：高温、低温、高压、磁场、水下金属式金属式金属式金属式：。