Magnet sensors in Low fluid level monitoring
Automobiles these days need to provide a wide range of information on the various liquid levels ranging from wind screen viper fluid, brake oil, power steering oil, radiator coolant and other. Reed sensors are the only devices that are hermetically sealed and completely safe to use even inside fuel tanks and they are molded, which means they can withstand higher shock and vibration limits that automobiles require. Detecting the actual volume of a liquid required additional PCB, but detecting only the low level is much simpler. Reed Sensors also have the added advantage of withstanding higher temperatures without very little or no change in actuating distance when the right magnets are used for actuation. Tanks are fitted with a foamed magnet float attached to the inside stem of the cap and are usually mounted in the middle of a tank so movement of the liquid when the vehicle is in motion does not affect the measurement much. A reed sensor is then mounted outside the tank at the near empty level. The magnet and reed sensor can be combined into one float switch which is inserted directly into the tank. The signal is then used to trigger an LED on the driver information panel. Some automobile manufacturers also mount the reed sensor to sense a full tank instead of an empty tank, because it will be easier to detect a malfunction.
Applications are classified as Position Sensing, Pulse Counting, Electromagnetic or Relay, Temperature Sensing or Magnet Biasing types. This application is classified as follows and the link gives more information on best practices to help select the most suitable AT band and matching magnet.
The Reed Switches and Sensors used in such applications need to be robust, durable and efficient in meeting a high life expectancy. Our engineers work hard in life testing our products under various conditions, and our intention is to ensure end product durability and life. Although we wouldn’t want to restrict any of our products for use in only certain applications, the recommended products for use in this application are listed below.
MM-1018 Micro Miniature Reed Switch
|This is durable and reliable, Form A type 10.0 mm Micro Miniature reed switch...Continue reading|
MS-105 Miniature PCB Mountable Reed Sensor
|This micro miniature PCB mountable reed sensor is designed for switching 10W. The sensors...Continue reading|