Magnet Sensors in Fluid Metering

In most large cities, utility companies or closed communities run piped Water and Liquefied Petroleum Gas, LPG, to all homes. The usage of such fluids is monitored by the meters that are connected to the line. This requires a person from the company to come over during the end of each billing period, to take readings and prepare the bills. To save costs on these visitations, utility companies started looking at ways and mean to capture readings directly, via the Internet.

This is where Magnet Sensors and Reed Sensors help. To make an existing analog meter generate digital output readings that can be transmitted, a square wave pulse should be generated for every turn of the smallest digit. The way to get this done is to embed a tiny magnet within the last digit and place a reed sensor just near it so that an on and an off is generated for every turn of this smallest digit on the meter. This sort of pulse counting application requires careful selection of AT band and magnet. Once the square is generated, it is correlated to actual consumption and can be transmitted to the utility company.

For such applications, specially designed reed switches with high spring back forces are suitable for use inside the reed sensor or magnet sensor. Even if the meter is unused for periods of up to three months and the reed sensor stays closed for all this time, the contact can easily open up and continue to work once the meter dial starts turning.

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

Pulse counting type application When an application requires the volume of a fluid, or a distance, or the RPM of a machine tool 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.

MS-108 Standard Size PCB Mountable Reed Sensor

Drawing of MS-108 Reed SensorDrawing of MS-108 Reed Sensor Pad Layout starFeatures10W Contact Rating. 20.3 mm PCB Pitch. Normally 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 -> Nov 8, 2022

LV-1925 Reed Switch for Line Voltage switching

The LV-1925 is a Line Voltage Reed Switch is designed for endurance at switching line voltage loads of 230V. Two versions are capable of Continue reading -> Dec 2, 2020