Fix them in accordance with the demands of the testing distance.Then according to the packing paper you use, refer to the Guide Grids（for reference of light source choice）to decide on the light source（take the green one as example）,and then decide the bright mark sensors on or the dark one to meet your machine`s need.Now you can adjust the sensitivity according to the following three steps（take,as example,that the outpue mark sensors on is a bright one,the packing paper is of light color and the background is dark color） 

  First,move the packing paper,cast the light on the background outside the sign.Turn the sensitivity control counter clockwise till to the end, then turn it clockwise till the indicator light just turns red,and remember the position of the sensitivity control is in the position of Point A as in picture 1.If the sensitivity control is tumed to the High position and the indicator light still does not turm red,then the High position is Point A.

  second,move the packing paper again,and when you cast the light on the center of the sign,the indicator light will turn red.Then turn the knob counter clockwise slowly till the indicator lamp just goes out,and remember the sensitivity control is in the position of Point B as shown in Picture 2

  After operating the above two steps correctly,you can then turn the sensitivity control to a position between Point A and Point B,that is,Position C as shown in Picture 3,and now the adjustment is finished. The longer the distance between Point A and B is,the higher the ratio of the chromatic aberration and the stabler the test will be. The distance must be at least one scale between Point A and point B,otherwise the test will not be stable.

操作步驟：

  固定好光電開關(guān),使檢距符合要求。根據(jù)您使用的需要確定開關(guān)的光源；再根據(jù)工作需要選擇亮動或暗動，并按照以下三步驟調(diào)節(jié)靈敏度。

（1）       移動包裝紙或我們稱之為底色、讓投光點落到標(biāo)記之外的背景區(qū)；將靈敏度旋鈕反旋到底，然后順時針慢慢轉(zhuǎn)至指示燈剛好亮，記住此時電位器位置如圖（一）的A點。若旋到高點的位置指示燈都不亮則高位置就為A點。

（2）       再移動包裝紙讓投光點照在需檢測的標(biāo)記上、指示燈應(yīng)是亮的，此時應(yīng)逆時針慢慢旋轉(zhuǎn)靈敏度旋鈕直至指示燈恰好熄滅記住此時的位置;如圖（二）的B點.