Reed switches and Reed sensors in Pressure Gauges
A pressure gauge is an instrument used to display the pressure of a fluid. The most widely used type of pressure gauge is the Bourdon gauge which uses a flattened tube that tends to straighten or regain its circular form with change in pressure. The flattened tube is directly coupled with the a mechanical arm that directly drive the needle of the display.
Legacy Bourdon tube pressure gauges are fitted with a magnet on the Bourdon tube itself so that as pressure increases, the magnet moves along a circumference. A circular PCB with multiple reed switches mounted from radial center to circumference, wired to generate a potentiometric two wire feedback is triggered by the magnet as the pressure changes. Circuits for such PCBs follow the same principles of level sensors, which is reed switches combined with resistors, and more information can be found here. This sort of assembly is cost effective and accurate. An added advantage in such gauges is that multiple alarm points can be set and the digital outputs can be saved to a web server or to a smart phone.
Application Classification
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.
Position sensing Type
 | Position Sensing type application When an application requires the end position of a movement sensed, or the sensing of a part when it Continue reading Nov 7, 2020 |
Recommended Products
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.
R2 Standard size SMD Reed Sensor
 | R2-S Gull-wing SMD Formed Reed SensorR2-S Gull-wing SMD Formed Reed Sensor Pad LayoutR2-F Low Profile SMD Formed Reed SensorR2-F Low Continue reading Dec 2, 2020 |
MM-1018 Micro Miniature Reed Switch
 | This 10.0 mm long, Form A type Micro Miniature reed switch is designed for moderate power, low load applications. The fast operate Continue reading Jun 2, 2021 |
MS-105 Miniature PCB Mountable Reed Sensor
 | Drawing of MS-105 Reed SensorDrawing of MS-105 PCB Pad Layout starFeatures10W Contact Rating. 12.7 mm PCB Pitch. Normally Open Continue reading Oct 30, 2020 |
SM-1322 Sub Miniature Reed Switch
 | This Form A type SM-1322 Sub Miniature Reed Switch is built with a 2.25 mm diameter glass with a higher wall thickness for better glass to Continue reading Dec 2, 2020 |