DIY liquid level sensor

Liquid level sensor

Hello dear readers. There are many different types of water level sensors. I want to offer you another homemade sensor design.

The task was as follows: there is plastic barrel, which must be closed with a lid, i.e. It was not possible to fence the probe sensors. The barrel had to pump drinking water in automatic mode as it is consumed. There must be visual control of the water level as a percentage, i.e. there should be ten sensors. And most importantly, permission to perforate the barrel was obtained.

So. To make sensors, we need unnecessary diodes (photo 1). I have a lot of KD202 diodes, so I will make a sensor from them. To begin, carefully, without disturbing the glass insulation, we cut off part of the upper terminal of the diode (anode for KD202). This output is tubular (photo 2). Then, using a drill with a diameter of one and a half millimeters, we drill the body of our diode, starting from the tubular terminal, all the way through. Drill carefully, strictly observing alignment. I drilled at once, in one pass, but you can drill in two times, from different sides (photo 3). Now the most important thing is to shake out all the shavings from the body of the completely damaged diode - there are a lot of them (photo 4), the photo shows that it will take a long time to knock, until the last speck of dust - otherwise the short one is guaranteed. If you have a compressor, then of course everything will be very simple and fast. Next, we take the wire, put it on a fluoroplastic tube with an outer diameter of 1.5 mm and insert it all into the hole drilled in the diode body. We solder one end of the wire, from the side of the tube, and on the other, from the end of the thread, we secure the resulting terminal with a drop of Supermoment glue or the like, forming a loop for further soldering of the wire (photo 6). It is better to make the internal conductor of the sensor, which will be located inside the container, longer than shown in my photo and increase the length of the tube. The problem is that after the water level drops, a drop of water may remain on the sensor body, which can cause the system to malfunction.
The sensors are connected to the automation board using twisted pairs of drives, or, even better, with a shielded wire. To indicate the level, a circuit with an LED bar is assembled. To install the sensor, a hole is drilled in the container body, how many of them will be up to you. You can only have two - on (lower) and off - upper. The sensor must be installed with auto-sealant to avoid leaks. I think he told me everything. If I catch my eye, I’ll post the diagram right away. Good luck to everyone. Goodbye. K.V.Yu.

Using your favorite timer 555, you can make a sensor for water, washer, antifreeze, etc. It is worth noting that such a sensor will be useful both in your car and in living conditions. The scheme is quite simple and easy to repeat. The microcircuit received widespread precisely because of its simplicity.

The following circuit will be used for the water sensor.

The operation of the device is extremely simple. When the electrodes are immersed in liquid, C1, the capacitor, is bypassed. When the electrodes are in the air, the shunt disappears and the microcircuit begins to work.

Rectangular pulses emanate from the microcircuit. With the help of such impulses it is possible to control using a larger load. For example, you can send a signal to a light bulb through a transistor. This technology allows you to include an alarm or indicator in the circuit. Using the latter, you can determine the presence of water in the tank. Such a sensor can be installed both in the tank and in the radiator. The sensor power supply is 12 volts. This means that there will be no problems with nutrition.

As a rule, sensors are made of fiberglass. But most often they use ordinary copper (wires). For the sensor, two identical pieces of wire with a cross-section of 1 millimeter are suitable. It is important to note that you need to remove any varnish that may be on the metal surface from the wires. This is done using fire or sandpaper. So, the length of the wire should be up to 3.5 centimeters.

To keep the wires in the plug, they are reinforced with silicone. Then the wires are attached to the microcircuit itself. The wires in the cover can be connected to the microcircuit with thinner conductors.

The microcircuit can be mounted - without an installation board. When everything is ready, the resulting device is closed with another similar lid. The connection between the covers must be sealed with glue or other means.

Thus, without incurring unnecessary costs, you can independently make a sensor that will help not only in the car, but also in everyday life. So, you can save yourself from frequently getting into the shower in order to check the water level in the tank. Homemade sensor water level will solve the problem. It is only important to carry out all work carefully and carefully so that the device works properly.

To regulate and control the liquid level or solid(sand or gravel) in production, in everyday life used special device. It is called a water level sensor (or other substance of interest). There are several varieties similar devices, significantly different from each other in their operating principle. How the sensor works, the advantages and disadvantages of its varieties, what subtleties you should pay attention to when choosing a device, and how to make a simplified model with a relay with your own hands, read in this article.

The water level sensor is used for the following purposes:

Possible methods for determining tank load

There are several methods for measuring liquid level:

1. Contactless- often devices of this type are used to control the level of viscous, toxic, liquid or solid, granular substances. These are capacitive (discrete) devices, ultrasonic models;
2. Contact- the device is located directly in the tank, on its wall, at a certain level. When the water reaches this indicator, the sensor is triggered. These are float, hydrostatic models.

Based on the principle of operation, they distinguish the following types sensors:

• Float type;
• Hydrostatic;
• Capacitive;
• Radar;
• Ultrasonic.

Briefly about each type of device

Float models are discrete and magnetostrictive. The first option is cheap, reliable, and the second is expensive, complex design, but guarantees an accurate level reading. However, a common disadvantage of float devices is the need for immersion in liquid.

Float sensor for determining the liquid level in the tank

1. Hydrostatic devices - in them all attention is paid to the hydrostatic pressure of the liquid column in the tank. The sensitive element of the device senses pressure above itself and displays it according to a diagram to determine the height of the water column.

The main advantages of such units are compactness, continuity of operation and affordability. But they cannot be used in aggressive conditions, because they cannot do without contact with liquid.

Hydrostatic liquid level sensor

1. Capacitive devices - plates are provided to control the water level in the tank. By changing the capacity indicators, you can judge the amount of liquid. Lack of moving structures and elements, simple circuit devices guarantee durability and reliable operation of the device. But one cannot fail to note the disadvantages - this is the necessity of immersion in liquid, and demanding temperature conditions.
2. Radar devices - determine the degree of increase in water by comparing the frequency shift, the delay between the radiation and the achievement of the reflected signal. Thus, the sensor acts as both an emitter and a reflection collector.

Such models are considered the best, accurate, reliable devices. They have a number of advantages:

The only disadvantage of the model is its high cost.

Radar tank liquid level sensor

1. Ultrasonic sensors - the principle of operation and the design of the device are similar to radar devices, only ultrasound is used. The generator creates ultrasonic radiation, which, upon reaching the surface of the liquid, is reflected and reaches the sensor receiver after some time. After some mathematical calculations, knowing the time delay and speed of the ultrasound, the distance to the water surface is determined.

The advantages of a radar sensor are also inherent in the ultrasonic version. The only thing is that the indicators are less accurate and the operation scheme is simpler.

Subtleties of choosing such devices

When purchasing a unit, pay attention to the functionality of the device and some of its indicators. Extremely important issues when purchasing a device, this is:

Options for sensors for determining the level of water or solids

DIY liquid level sensor

You can make a basic sensor to determine and control the water level in a well or tank with your own hands. To perform the simplified version you need:

A do-it-yourself device can be used to regulate water in a tank, well or pump.

In industry and everyday life, there is a constant need to monitor the levels of liquids in containers. Measuring devices are classified as contact and non-contact. For both options, the water level sensor is located at a certain height of the tank, and it is triggered, signaling or giving a command to change the mode of its supply.

Contact devices operate on the basis of floats that switch circuits when the liquid reaches specified levels.

Non-contact methods are divided into magnetic, capacitive, ultrasonic, optical and others. The devices have no moving parts. They are immersed in controlled liquid or granular media or fixed to the walls of tanks.

Float sensors

Reliable and cheap devices for monitoring liquid levels using floats are the most common. Structurally, they may differ. Let's look at their types.

Vertical arrangement

A float water level sensor with a vertical rod is often used. There is a round magnet placed inside it. The rod is a hollow plastic tube with reed switches located inside.

A float with an attached magnet is always located on the surface of the liquid. Approaching the reed switch, the magnetic field triggers its contacts, which is a signal that the container is filled to a certain volume. By connecting contact pairs in series through resistors, you can constantly monitor the water level based on the total resistance of the circuit. The standard signal varies from 4 to 20 mA. The water level sensor is most often placed at the top of the tank in an area up to 3 m long.

Electrical circuits with reed switches may differ even if the mechanical part is similar in appearance. Sensors are located at one, two or more levels, giving a signal about how full the tank is. They can also be linear, transmitting a signal continuously.

Horizontal arrangement

If it is not possible to install the sensor from above, it is attached horizontally to the wall of the tank. A magnet with a float is installed on a lever with a hinge, and a reed switch is placed in the housing. When the liquid rises to the upper position, the magnet approaches the contacts and the sensor is triggered, signaling that the limit position has been reached.

In case of increased contamination or freezing of the liquid, a more reliable float water level sensor on a flexible cable is used. It consists of a small sealed container located at depth with a metal ball with a reed contact or toggle switch inside. When the water level coincides with the position of the sensor, the container turns over and the contact is activated.

One of the most accurate and reliable float sensors is magnetostrictive. They contain a float with a magnet that slides along a metal rod. The principle of operation is to change the duration of passage of an ultrasonic pulse through the rod. The absence of electrical contacts significantly increases the clarity of operation when the interface reaches a given position.

Capacitive sensors

The non-contact device responds to the difference between the dielectric constant of different materials. The water level sensor in the tank is installed outside the side wall of the tank. In this place there should be an insert made of glass or fluoroplastic so that the interface between the media can be distinguished through it. The distance at which the sensitive element detects changes in the controlled environment is 25 mm.

The hermetic design of the capacitive sensor makes it possible to place it in a controlled environment, for example, in a pipeline or in the lid of a tank. However, it may be under pressure. In this way, the presence of liquid in the closed reactor is maintained during the technological process.

Electrode sensors

A water level sensor with electrodes placed in a liquid responds to changes in electrical conductivity between them. To do this, they are secured with clamps and placed at the extreme upper and lower levels. Another conductor is installed in pair with the longer one, but usually a metal tank body is used instead.

The water level sensor circuit is connected to the pump motor control system. When the tank is full, all electrodes are immersed in liquid and a control current flows between them, which is a signal to turn off the water pump motor. Water also does not flow unless it touches the exposed upper conductor. The signal to turn on the pump is a decrease in the level below the long electrode.

The problem with all sensors is the oxidation of contacts in water. To reduce its influence, use stainless steel or graphite rods.

DIY water level sensor

The simplicity of the device makes it possible to make it yourself. This requires a float, a lever and a valve. The entire structure is located at the top of the tank. A float with a lever is connected to a rod that moves the piston.

When the water reaches the upper limit level, the float moves a lever that acts on the piston and closes the flow through the lower pipe.

As the water flows, the float lowers, after which the piston again opens the hole through which the tank can be refilled.

At making the right choice and manufacturing a water level sensor, assembled with your own hands, works reliably in the household.

Conclusion

The water level sensor is indispensable in the private sector. With it, no time is wasted when monitoring the filling of the tank in the garden, the level in the well, borehole or septic tank. A simple device will start or turn off the water pump in time without the help of the owner. Just don’t forget about its prevention.

" It happens that you need to find out how much water is left in some opaque container. For example, a tank, barrel or any other, buried in the ground or raised to a height so that its contents are not visible. Then a water level sensor will come to the rescue. The circuit is so simple that even someone who has just picked up a soldering iron can repeat it. It consists of only 10 resistors, 3 transistors and 3 LEDs.

Let's start building the sensor circuit. First, we cut the board 30 mm by 45 mm. Then we will draw the paths, as in the photo. It is advisable to paint with paint or nail polish. But I only had a marker on hand (I would like to note that only a permanent marker will do). If you draw with a marker, then a marker purchased from a CD or computer store will hold up best. Once you've drawn, start etching.

I poisoned with hydrogen peroxide, since neither ferric chloride nor copper sulfate No. I poured 50 ml of 3% hydrogen peroxide, then put 1 spoon of salt and 2 spoons citric acid. Mixed until everything was dissolved. With occasional gentle rocking, I etched the board in about 50 minutes.

Let's start soldering the circuit. For this we need: 3 resistors with a resistance of 10 kOhm, 3 resistors with a resistance of 1 kOhm, 2 green and 1 red LEDs, 4 resistors of 300 Ohms. Having carefully soldered everything in, solder the wires and connect the battery. We cut the wires every 2 centimeters.

Ready! Now we lower the wires into the glass and gradually pour water. For clarity, I slightly tinted the water. As you can see, everything works great.

When the glass contains 1/3 of water, only the red LED lights up. When 2/3, the green light also lights up. And when the glass is filled to the top line, all the LEDs light up. in my case, I assembled a circuit with only 3 LEDs, but you can do more - at least 10. Then the water level will be visible more accurately. I would also like to add that the case was used under a corrector. I assembled the diagram: bkmz268

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