Fluid Metering Using Reed Sensors

In many major cities, utility companies or gated communities manage the distribution of piped water and Liquefied Petroleum Gas (LPG) to households. Monitoring the usage of these fluids is facilitated by gas meters connected to the pipelines. Traditionally, personnel from the utility company visit homes at the end of each billing cycle to manually read the meters and prepare bills. Seeking to reduce costs associated with these visits, utility companies have explored methods to capture readings directly via the Internet.

This is where Magnet Sensors and Reed Sensors come into play. Converting an analog meter into a source of digital output readings suitable for transmission entails generating a square wave pulse for each revolution of the smallest digit on the meter. Achieving this involves embedding a small magnet on the gear wheel turning the last digit and positioning a reed sensor nearby, ensuring that each rotation of this smallest digit triggers an on and off signal. Precision in pulse counting necessitates careful selection of the appropriate AT band and magnet. Once the square wave is generated, it is correlated with actual consumption data and can be transmitted to the utility company electronically.

For such metering applications, specially engineered reed switches with high spring back forces are ideal for integration within the reed or magnet sensors. These switches ensure reliable performance even if the meter remains unused for extended periods, up to three months, and the reed sensor remains closed throughout. Upon resumption of meter activity, the contacts easily reestablish functionality, ensuring continuous operation.

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.

Pulse Counting Type

When an application requires the volume of a fluid, or a distance, or the RPM of a machine tool measured, such an application can be Continue reading -> Jun 18, 2025

Recommended Products

The Reed Switches and Sensors used in such fluid metering 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.

Standard PCB Mountable Reed Sensor, MS-108

Drawing of MS-108 Reed SensorDrawing of MS-108 Reed Sensor Pad Layout starFeatures10W Contact Rating. 20.3 mm PCB Pitch. Normally Continue reading -> Jul 14, 2025

Sub Miniature Reed Switch, SM-1322

Reed Switch with Full Length LeadsCropped LeadsSMD Formed LeadsHorizontal MountingVertical Mounting starFeaturesRelease AT Continue reading -> Jul 14, 2025

Line Voltage switching Reed Switch, LV-1925

Full Length LeadsCropped LeadsSMD Formed LeadsVertical MountingHorizontal Mounting starFeaturesContact Rating Configurable. Ruthenium Continue reading -> Jul 14, 2025