APL-100限位开关就是用以限定机械设备的运动极限位置的电气开关。限位开关有接触式的和非接触式的。接触式的比较直观，机械设备的运动部件上，安装上行程开关，与其相对运动的固定点上安装极限位置的挡块，或者是相反安装位置。当行程开关的机械触头碰上挡块时，切断了（或改变了）控制电路，机械就停止运行或改变运行。由于机械的惯性动这种行程开关有一定的“超行程”以保护开关不受损坏。非接触式的形式很多，常见的有干簧管、光电式、感应式等，这几种形式在电梯中都能够见到。
M2：2-SPDT
M3：3-SPDT
M4：4-SPDT
M5：2-DPDT
MG2：2SPDT镀金触点
ML2：2SPDT-40℃
MZ：直行程
PP：P+F(NAMUR)
   (Exia Ⅱ CT6）
PA：电感接近（2or3）
QA：磁感接近（2or3）
F：4-20mA阀位反馈
K：0-1K阻值输出
W：2.4Ghz无线通讯

APL-100限位开关APL-100行程开关APL-100回迅器APL-100阀位显示APL-100气动附件作为工业自动化控制系统中的重要执行机构，可远距离集中控制能满足计算机程控的需要；如今在石油化工、燃气设备、核工业、电力装备、环保水处理、暖通空调、钢 铁冶金、工业窑炉、罐装设备、酿酒设备、干燥设备、真空设备、表面处理、生物制药、食品机械、纺织印染、造纸等行业中得到广泛的使用，也是国防建设、科技 建设的首选产品。
The function of APL-100 limit switch is to realize sequence control, bing control and b status detection. Used to control the travel and limit protection of mechanical equipment. Structure: composed of operation head, contact system and housing.
APL-100 limit switch is an electrical switch used to limit the movement limit b of mechanical equipment. There are contact and non-contact limit switches. The contact type is more intuitive. The moving parts of the mechanical equipment are equipped with a travel switch, and the stop point of the relative movement is installed with a limit stop, or the opposite installation b. When the mechanical contact of the travel switch hits the stop, the control circuit is cut off (or changed), and the machine stops or changes its operation. Due to the mechanical inertia, this travel switch has a certain "over travel" to protect the switch from damage. There are many bs of non-contact type, the common ones are reed switch, photoelectric type, induction type, etc. These types can be seen in the elevator.
APL-100 limit switch APL-100 travel switch APL-100 echo device APL-100 valve b display APL-100 pneumatic accessories as an important actuator in industrial automation control system, can be centralized control from a long distance can meet the computer program control Need; now in petrochemical industry, gas equipment, nub industry, power equipment, environmental protection water treatment, HVAC, iron and steel bllurgy, industrial kilns, canning equipment, brewing equipment, drying equipment, vacuum equipment, surface treatment, biopharmaceutical It is widely used in food machinery, textile printing and dyeing, paper making and other industries, and is also the first choice for national defense construction and technology construction.