箔式应变片的优点：
?
1、尺寸精确，线条均匀，灵敏系数、电阻值离散小。 ?2、横向效应小，粘结面积大，粘贴牢固，散热性好。?3、光刻腐蚀可制成各种应变花及小标距应变片。?4、耐潮湿，绝缘性好，蠕变及机械滞后小。?
5、便于成批生产，质量好，成品率高。
6 应变测量系统框图
数字式静态应变仪 电阻应变仪 应变片 动态应变仪 数据采集器 记录设备 示波器 光线振子示波器 毫伏表 磁带记录仪 X-Y记录仪
7 二.电阻应变效应
K：应变片的灵敏系数。 8 灵敏系数
dRd?dL??(1?2?)R?L?RRK??xK0?(1?2?)?d???9 2.
Temperature Compensation
Ambient temperature changes affect the performance characteristics of the gauge in the following ways.
- strain sensitivity of the metal alloy changes.
??/????T- grid elongation/ contraction governed by
- component elongation/ contraction. (base metal) - Resistivity changes governed by
?R/R???T
The effect of gauge grid, base material elongation and resistivity changes may be combined to give.:
??R????Sg??????T???T?R??TThis may be minimized by letting ??? and using materials with a low value of ? 10