What is a flow detection sensor?

A flow detection sensor which is also called a flow meter is an electronic device that measures the flow rate of liquids and gasses. Flow detection sensors can detect leaks, blockage, pipe bursts, and changes in liquid concentration which is occurred due to pollution.

Uses of flow detection sensors

• Flow sensors are utilized in practically all fields of cycles and plant designing where fluids or gases are utilized. For coolant and ointment supply of plant and apparatus, ventilation of establishments and structures and the handling of items, etc. In the event of no appropriate stream, significant harm and personal time might result. Mistaken stream estimations or inability to take estimations might cause extreme unfavourable outcomes. In present-day establishments, electronic stream screens are utilized for this reason.
• Flow sensors are utilized to gauge the stream pace of blood or oxygen through a vessel. Implantable stream sensors are generally consolidated into an adaptable sleeve that is fitted around the vessel whose stream rate is to be estimated.

Working principle of the flow sensor

The flow sensor comprises a plastic valve from which water can pass. A water rotor alongside a lobby impact sensor is available to sense and measure the water stream at the point when water courses through the valve it turns the rotor. By this, the change can be seen in the speed of the engine. This change is determined as a result of a pulse signal by the lobby impact sensor. Hence, the pace of the stream of water can be estimated. The working rule behind the working of this sensor is the Hall effect. As indicated by this standard, in this sensor, a voltage contrast is prompted in the guide because of the turn of the rotor. This incited voltage distinction is crossed over to the electric flow.

At the point when the moving fan is turned because of the progression of water, it pivots the rotor which incites the voltage. This incited voltage is estimated by the corridor impact sensor and shown on the LCD show. Stream sensors can be utilized with hot waters, cold waters, warm waters, clean water, and filthy water too. These sensors are accessible in various measurements, with various stream rate ranges. These sensors can effectively interact with microcontrollers like Arduino. For this, an Arduino microcontroller board for handling, a Hall effect water stream sensor, a 16×2 LCD show, and Breadboard interfacing wires are required. The sensor is put at the water source delta or the kickoff of the line. The sensor contains three wires. Red wire to associate with supply voltage. Dark wire to associate with the ground and a yellow wire to gather yield from the Hall effect sensor. For supply voltage 5V to 18V of DC is required.

Types of flow detection sensors

There are many types of flow detection sensors that are described in detail below:

Positive displacement flow sensor

Positive Displacement flow meters are the mainstream estimating innovation to straightforwardly gauge the volume of liquid that passes however the stream meter. It accomplishes this by catching pockets of liquid between turning parts housed inside a high accuracy chamber. This can measure up to over and over filling a receptacle with liquid and pouring the substance downstream while counting the occasions the container is filled. Rotor rotational speed is straightforwardly corresponding to stream rate since the progression of liquid is causing the pivot. In electronic stream meters, the turning parts contain magnets that initiate different sensor choices situated external to the liquid chamber. Mechanical positive relocation stream sensors depend on the pivot to drive either an attractive coupling or an immediate stuff train associated with the mechanical counter. PD stream meters do not need a power supply for their activity and nor do they need straight upstream and the downstream line runs for their establishment. Positive removal stream meters are accessible in sizes from 12 inch and can work with turndowns as high as 100:1, even though scopes of 15:1 or lower are significantly more typical. The slippage between the stream meter parts is diminished and metering precision is along these lines expanded as the consistency of the interaction liquid increments.

Mass flow sensor

A mass flow sensor is a sensor used to decide the mass stream pace of air entering a fuel-infused gas-powered motor. The air mass data is important for the motor control unit to adjust and convey the right fuel mass to the motor. Air changes its thickness with temperature and strain. In-car applications, air thickness fluctuates with the surrounding temperature, height, and the utilization of constrained acceptance, which implies that mass stream sensors are more fitting than volumetric stream sensors for deciding the amount of admission air in every chamber. There are two normal sorts of mass wind current sensors being used on car motors. These are the vane meter and the hot wire. Neither one of the plans utilizes innovation that actions air mass straightforwardly. In any case, with extra sensors and data sources, a motor's ECU can decide the mass stream pace of admission air.

Velocity flow sensors

Velocity flow sensors work on Faraday's law of electromagnetic enlistment that expresses that a voltage is incited when a guide travels through an attractive field. The fluid fills in as the guide and the attractive field is made by invigorated loops outside the stream tube. Electromagnetic stream meters must be utilized for electrically conductive liquids, like water. They can't gauge de-ionized water or most hydrocarbon-based fluids. The resulting voltage created by the electromagnetic enlistment is straightforwardly relative to the stream rate. Terminals mounted in the line divider identify the voltage which is estimated by an auxiliary component. Electromagnetic stream meters have no moving parts. They are chosen for their capacities to gauge troublesome and destructive fluids and slurries with extremely low tension drop parts and are great for wastewater applications or any grimy fluid which is electrically conductive. Most meters offered have exactnesses between 0.3 to 1% of perusing.

Common Mistakes

• Impacted by over-burdening and fast changes at high differential tension, risk of over speeding.
• Solids harm metering edge, in any case, slight defilement permitted.
• Damaging, along these lines higher space prerequisites upstream of the estimating point.
• Divert narrowing bringing about damming of the head water and hazard of store develop in case of speed decline.

Context and Applications

In each of the expert exams for undergraduate and graduate publications, this topic is mainly used for

• Bachelor of Electrical Engineering
• Bachelor of Electronics Engineering
• Masters of Electrical Engineering

Related Concepts

• Ultrasonic flowmeter
• Vortex flowmeter
• Magnetic flow meter
• Positive displacement meter

Practice Problems

Q1. The touch screen of mobile uses _______.

1. AFR sensor
2. pellistor
3. tactile sensors
4. None

Correct option: (c)

Explanation: The contact screen of cell phones utilizes material or capacitive touch sensors.

Q2. Which kind of sensor is utilized to quantify the distance between the vehicle and different articles in their current circumstance?

1. Ultrasonic sensor
2. Tactile sensor
3. Motion sensor
4. None

Correct option: (a)

Explanation: Self-driving vehicles are stacked with ultrasonic sensors that action the distance among vehicles and different items.

Q3. The  _____________ velocity is constant at every point at a specific time.

1. steady flow
2. rational flow
3. non-steady flow
4. None

Correct option: (a)

Explanation: In a steady flow fluid, the velocity of all points will be constant at a specific time.

Q4. What is it known as if all fluid particles have a path parallel to the wall?
       (a) Streamline flow
       (b) Laminar flow
       (c) Viscous flow
       (d) All of the mentioned

Correct option: (d)

Explanation: If all particles of fluid have a parallel path with the wall, it is called laminar flow, also known as viscous flow and streamline flow.

Q5. Which of the following represent the Reynolds number for laminar flow?
       (a) Less than 2,000
       (b) Greater than 4,000
       (c) Infinite
       (d) None of the mentioned

Correct option: (a)

Explanation: Reynolds number is an indication of the flow of fluid. For a Reynolds number less than 2,000, fluid is in laminar flow. For greater than 4,000, fluid is in a turbulent flow.