Measuring Water Flow Using a Reed Sensor

Introduction

There are a multitude of applications that require the measurement of the volume of water. Water filters must measure the amount of water passing through them in order to know when to change the filter. In many cases these newer filters may be directly connected to the tap water in the home. Also many of these newer refrigerators, also used in the home, are directly connected to a filtered water line. Designers have chosen Standex Electronics’s reed sensors as an inexpensive way to accurately measure the volume of water passing through these filters.

Full Application Write Up

Measuring Water Flow Volume to Detect Filter Replacement - Flow Level Sensor

Features

Magnet and reed sensor are isolated and have no physical contact by typically having the magnet mounted to a mini paddle wheel, and the reed sensor is mounted strategically such that the magnetic field of the permanent magnet will be sensed with each rotation of the paddle wheel.
The reed switch used in the reed sensor is hermetically sealed and is therefore not sensitive to wet, watery environment
The permanent magnet is not affected by its environment
Tens of millions of reliable operations
Surface mounting and through hole mounting
Cylindrical hole and screw fastening mounting
Contacts dynamically tested

Series	Dimensions	mm	inches
MK15	W	2.5	0.098
	H	2.5	0.098
	L	19.50	0.768
MK16	W	2.3	0.091
	H	2.3	0.091
	L	15.60	0.614
MK17	W	2.1	0.083
	H	2.1	0.083
	L	9.61	0.378
MK22	W	2.7	0.106
	H	2.3	0.091
	L	15.60	0.614
MK23-35	W	2.2	0.087
	H	1.95	0.077
	L	15.75	0.620
MK23-66	W	2.2	0.087
	H	2.7	0.106
	L	19.60	0.772
MK23-87	W	2.0	0.079
	H	2.1	0.083
	L	15.60	0.614
MK23-80	W	2.0	0.079
	H	2.1	0.083
	L	13.0	0.512
MK24	W	2.2	0.086
	H	1.8	0.070
	L	5.5	0.216