Basic Knowledge

Hall Effect Water Flow Sensor

2020-02-04 10:24:03 isentrol

Hall Effect Water Flow Sensor

Features:

Low cost solution

Pulse output for flow totalizing

Compact size

Different structure/style optional

Convenient to install and use

Compliant with ROHS

Food safe grade available(Stainless steel or plastic material)

Hall effect flow sensor provides low cost solution for water flow measurement. Hall effect water flow sensors include 3 main parts: sensor body, hall effect part and paddle wheel sensor. There are 3 kinds of material for the flow sensors. They are stainless steel,  brass and plastic plastic(e.g.POM). Stainless steel is expensive, so it is not main selling item. Thus, we will mainly introduce brass and plastic.

Hall effect water flow sensors can sense water flow by built-in wheel sensor. By the operation the flow sensors can calculate how much liquid flows through it.The hall effect parts inside flow sensor is sealed from the liquid and can make the sensor under dry and safe status. When flow sensors start to count flow rate, the magnetic hall effect sensor outputs an electrical pulse with every period.

The low cost water flow sensor is mainly used for small pipe size and usually below DN50mm. It supports hall effect pulse output and can output pulse to PLC, oscilloscope, or other pulse counter device. The pulse from hall effect sensor is simple square wave,thus it is very easy to use. With the pulse output, user can log and convert it to flow rate at liters per minute. The flow rate and pulse has certain formula relationship.

We can also supply secondary flow totalizer to gather pulses from the hall effect water flow sensor. By the flow totalizer, flow rate is accumulated.

Application:

Water Dispenser,Coffee Machine

Water Heater (Solar, Electric, Gas)

Steam Equipment

Prepaid Water Supply

Cooling System

Mechanical Equipment,Instrumentation

Water Processing Equipment

pharmaceutical equipment


Food Safe Flow Meter


Food safe flow meters have been widely used for pharmaceutical, food, beverage and other industries. Food safe flow meters mainly have stainless steel turbine flow meter, stainless steel magnetic flow meter, clamp on ultrasonic flow meters and hygiene class hall effect flow sensors. When used for food grade application,the pipe size of hall effect flow meters are usually not over 30mm. Meanwhile, comparing with other types,hall effect water flow sensors are one of the cheapest solution. Because stainless steel hall effect flow sensor is expensive, it is firstly recommended to consider food class plastic hall effect flow sensor. The following are the main specification of plastic hall effect flow sensor.

Specification:

Accuracy: +/-5%

Pipe size: 1/4", 1/2", 3/4"

Power supply:4.5-18Vdc. 24Vdc or low power consumption can be made as requirement.

Output voltage: rated 5Vdc(<=10mA)

Temperature range: <=60 Deg.C. For higher temperature, require special order.

Pressure:<=0.8MPa

Storing humidity: 25%-95%RH

Notes:
1.POM material is manufactured as FDA standard.
2.Each size has its Min/Max flow rate. Flow should fall into range, otherwise the flow sensor can't work well. For exact flow range, please feel free to contact us.
3.The water flow sensor is more suitable for small size pipe and have no requirement of high accuracy.
4.Comparing with liquid turbine flowmeter, its performance is less weaker, but price of turbine meter is higher.

 

Accuracy Explanation of Hall Effect Flow Sensor
As an economic solution, hall effect flow sensors are used to keep the accuracy of 5% or better. The accuracy has a close relationship with flow stability. More stable the flow, the accuracy is better. Generally speaking, the pipe is smaller, the accuracy is higher. The accuracy of small pipe can reach to 99%.

Can Accuracy be Adjusted? How To?
Flow meter/flow sensor requires calibration to improve its accuracy. For hall effect sensor, its pulse equivalency is not fixed. That means each pulse may express different flow rate(liter). Our value is just for reference. Users can do the calibration during actual operation. While calibrate, please certain time pulse quantity and flow rate as standard data. Test for several times (3-5 times) and get the average value.

Pipe Size and Flow Rate

Hall effect flow sensor is designed for economic liquid flow measurement,so its flow rate range is not very wide and max pipe is not big. Usually, its max pipe size is below DN80mm. So when you select hall effect flow sensor, you should check whether its flow rate is suitable. If pipe size is over 80mm, it is also better to consider other type flow meters,e.g. paddle wheel, turbine, ultrasonic,magnetic,etc.


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