water level switch

Sorry, is it only me, not being sure how to use this? Please give us some brief overview so we can order with more confidence. Thanks a lot!

I'm fairly certain this is a magnetic reed switch. Connect one wire to the + of a 3V battery pack, the other wire to the anode (+) of an LED and finally the LED cathode (-) to the battery negative. When you slide the float it'll turn on and off. For use with an Arduino, the easiest way to use this is to setup any digital pin as INPUT_PULLUP and then connect the one switch wire ground and the other to the digital pin you picked. The following sample should work on an Uno (I didn't actually try it) to make the built-in LED on digital 13 light up and turn off according to the switch state: void setup() { pinMode(13, OUTPUT); pinMode(2, INPUT_PULLUP); } void loop() { digitalWrite(13, digitalRead(2)); }

How can i use it ?

I want to measure the level of a tank of 3.6 m in height, I need 16 points of measurement. How could i use this water level switch for this. thanks for response