DIY digital fuel indicator. Electronic fuel level indicator - how to check it? Fuel level sensor with analog output signal

I decided to make a digital indicator of the amount of fuel for a truck (bus), using a standard (rather mediocre) fuel level sensor...

Read the entire creation process and what came out of it in the article below.

Initial conditions:

• Truck (bus) with on-board voltage 24v
• Fuel tank for diesel fuel on 220l
• Fuel level sensor DUMP39
• Fuel level indicator EI8057M-3

Need to:

Make a digital fuel level indicator using a standard level sensor.

First, you will have to carefully study what a standard fuel level sensor, called a fuel level sensor, is. Let's dismantle it and examine it carefully.

As you would expect, there is a float, a rod, a variable resistor... wait, more about the variable resistor. As they say, it is better to see once than to hear a hundred times:

The design is both logical and clumsy. It is logical that the slider slides not directly over the variable resistance (which is quite delicate), but along the metal taps from it, but for such an increase in reliability you have to pay for discreteness. The clumsy thing about this design is that, as can be seen in the photo, in the middle position of the float we have a fairly large “dead zone”, due to the very wide central outlet from the resistance. Why this was done, we can only guess, but what we have, we will have to work with.

So, we rummage through the Internet and look for information. Here's what I dug up:

Float movement range - 412mm

Nominal resistance - 800 Ohm (according to another source, the nominal resistance is 761.0 – 193.5 Ohm)

Operating range from -40°С to +60°С

MTBF - 400 thousand. km to 95% wasting resources

Weight 160 gram, analogue - MAZ.

In general, not a lot.

We take the tester and measure it, and in the end we get the following picture:
Connection diagram:

Measured sensor parameters:

Total resistance - 767 Ohm

Additional resistance - 187 Ohm(it provides the minimum sensor resistance).

Left (from the photo) part of the resistance - 203 Ohm (13 taps to the slider), right side Ohm 376(17 taps to the slider).

Two metal sectors above the contact group - the left sector is not used, the right one goes to the fuel reserve lamp.

In general it's like this detailed description I present it only for those who are curious, but we need the voltage value that we have at the output contact when at different levels fuel. With the extreme left position of the contact at the output, we got 1.57v, at the extreme right position 3.28v, half a tank - 2.44v. At the beginning of the sector of switching on the lamp of the remaining reserve 2.95v.

More for the curious. General scheme connecting the fuel level sensor looks something like this:
Reels L1A, L1B, L2- this is a deflection system of the fuel level indicator (essentially a milliammeter). The resistor is thermal compensation.

In fact, this is a diagram of a classic electromagnetic automotive device, specifically EI8057M-3- this is something else: there is an electronic circuit inside, the arrow is driven by a stepper motor, and all this is controlled using a microcontroller PIC.

In principle, this is enough to calibrate a digital indicator, if not for a couple of troubles:

1. Specified fuel tank capacity in 220l not true, in fact the tank holds more fuel.

2. In the extreme right position of the movable contact of the sensor, when there is supposedly no more fuel in the tank, in fact the float should already be below the tank level, which is, of course, nonsense (determined by the geometry of the tank and the fuel level sensor.

3. Having measured the geometry of the tank with a tape measure, we are convinced that it is a rectangular parallelepiped with slightly rounded long edges, dimensions 40x112x60 cm. Multiplying the sides accordingly, we get an internal volume of 268 liters, which, you see, is very different from the declared 220 l, and it is very doubtful that the internal partitions, mesh, fuel intake, etc. occupy almost 50 l.

4. As already written above, the resistance of the sensor over the length of its resistance is nonlinear.

What we do:

Fill the tank full and control the voltage at the FLS output. It turns out that after reaching the mark 1.57v The tank still contains a good twenty liters of fuel.

Remove the float and put the sensor in place. Naturally, the draft, devoid of a float, goes to the very bottom of the tank, look at the voltage - it is 3.02v! This is important because in fact, in this position there is no longer any fuel in the tank, and the moving contact has not yet reached the extreme position in 3.28v, while the standard device EI8057M-3 shows what's left in the tank 1/8 volume. (Putting the float in the central position, at standard EI8057M-3 we observe instead of the required ones 1/2 tank as much 5/8 level, with a full tank the standard device goes off scale).

We look at the graph of our fuel level sensor,

Let's take three points - the resistance of the sensor, the first point is its lowest resistance (moving contact on the left) formed by additional resistance in 187 Ohm(in the photo there is a vertical black rectangle), the second point at the middle position of the contact when connected in series 187 Ohm And 203 Ohm, i.e. 390 Ohm, the total resistance will accordingly be 390 + 376 = 766 Ohms.

(horizontally - resistance in Ohms, vertically - conventional units of length)

There is nothing pleasant in this picture; the sensor seems to be linear but has a significant kink.

With such a picture, we will either get accuracy in the middle, or at the ends of the broken line, or something in between by approximating:


Having received the formula with the correction and coefficient, you can, in principle, make something similar to a digital fuel level indicator, coefficient R 2 trend lines in 0,97 Of course it’s not bad, you can, in principle, use anything greater than 0.95.

But you can get your own conversion factor for each line, which will be more accurate:
We immediately measure the ADC value at the points we need so that 5% The tolerance for the divider resistors at the ADC input did not spoil anything for us and we get it in the range of an empty tank (ADC822) before 1\2 tank (ADC700):

(horizontally the received ADC readings, vertically the volume of fuel in liters)

Ranges from 1\2 tank (ADC700) to full (ADC456):

From the above we have the following:

1. As the amount of fuel increases, the resistance of the sensor decreases and the voltage drop across it decreases.

2. The sensor voltage delta is 1.45v, that at 10 bit ADC will be 56% which is more than enough to scale the ADC result to scale 0....220l and will allow you to simply digitize the result without using OU to adjust to the desired voltage range.

The scheme is incredibly simple:


Microcontroller Mega8, LED indicator on 3 discharge with a common cathode, input divider of two resistors R1, R2. Zener diode (in bourgeois zener "zener" diode :)) to protect the input MK just in case. I didn’t draw the power circuits, they are classic 0.1uF ceramics and some kind of electrolyte 100...1000uF as well as quenching resistors between the MK and the indicator, any in the range will do 80...100Ohm depending on the MK supply voltage and the brightness of the indicator. The voltage on board the car with the engine running was 27.5v.

My board layout:

On the right side of the board I placed a power converter that provides 5v at onboard voltage 10...30v the converter is assembled on MS3406 3 according to the typical diagram from the datasheet. throttle murata 1812. The zener diode indicated in the diagram is 3.3v I screwed up when wiring and soldered on top.

Why did I apply Mega8 when there is a much more convenient one Tiny26 and so on. ? because Mega 8 available 1kB RAM, why so much? The microcontroller not only measures the voltage at the input and displays the recalculated value on the indicator, it constantly records the measured values ​​in one of 256 memory cells, filling them in a vicious circle and after recording each cell, it calculates the average value over all currently available 256 cells.

The indicator is located outside the board on the car's dashboard and is connected to it 11 wire loop. The board fits into a tiny case (the second one is the one with 4 wire terminals) excess plastic The side cutters were removed from the body.

The board is single-sided, without jumpers:

First, I unsoldered the PWM switch and checked the work, it works. varnished. you can continue building:

P.S. The project was created with the enormous support of Roman Viktorovich, for which many thanks to him, also thanks to the man Johnson from Ukraine for mathematical help and some ideas.

Used with the original level sensor (in the tank), and instead of the standard pointer (on the dashboard).
This device (based on 16f676) displays the readings of the fuel sensor in the tank (40 l) on a two-digit seven-segment (with a common anad). Power supply from the car’s on-board network is 12 V. We connect the sensor in the tank to the “in” input.

Modern world innovative technologies is full of many different devices through which human life is made easier. This progress has not spared the automotive world either. Thus, in the twenty-first century, all the efforts of manufacturers were thrown into creating the most comfortable conditions for the movement of motorists. Initially, all aspirations were aimed at achieving maximum comfort due to a smooth ride, a cozy interior, quiet operation of the car, etc. But in subsequent years, manufacturers began to pay attention to the most insignificant, at first glance, details, which not even all motorists know or have an idea about. One of these elements is the fuel level sensor, which, depending on the design of the vehicle, as well as on the preferences of the motorist, can be different types: analog, ultrasonic, electronic and others.

Cars that have a carburetor engine type prefer to use analog fuel level sensors, while injectors tend to use ultrasonic and electronic sensors. Accordingly, digital and ultrasonic sensors are newer models, which have overwhelmingly replaced older analog ones.

All automobile “titans” know that a huge part of all expenses that are directly related to the maintenance and provision of a vehicle is due to the fact that the car consumes fuel, which is purchased by the car enthusiast. Therefore, you should always monitor the level of this fluid in your car. This can be done using various tools and devices. However, the most popular and widespread is

Before the “automotive revolution,” manufacturers installed mechanical sensors directly on the fuel tank, as a result of which the driver needed to check the fuel level before each trip in order to predetermine a potential fuel shortage. Inexpensive cars and models were equipped with these primitive systems until the 30s of the twentieth century.

IN modern world same kind of fuel level sensors, as well as various warning lamps low level fuel, automakers install on almost all vehicles. The vast majority of fuel level sensors have the shape of a metal rod. The design is that the device is installed in a specially drilled or standard hole in the fuel tank. Using this device, the motorist can control the level, excess and fuel consumption of his vehicle.

1. How the electronic fuel level indicator works.

Of course, it becomes clear that electronic fuel level indicators are fundamentally different from analogue ones. This categoricalness lies in the fact that digital signs have an auxiliary electronic board. It is this board that is capable of analyzing all the readings that are received from the sensor, as a result of which they are transmitted to standard equipment or to a monitoring system that is already installed inside the vehicle via a digital protocol. In this design, the price will depend on the functionality of this type of board. The difference between the boards themselves lies in the accuracy of the sensor data. In general, the accuracy of readings from electronic structures is an order of magnitude higher than the analog accuracy of sensors, and the payback period of digital sensors is much lower.

Due to the fact that the weather conditions in our region are quite alarming, since the air temperature is constantly changing, it cannot be ruled out that various types of physical phenomena may occur that affect the readings of the electronic fuel level indicator. It's no secret that when cooled or heated, a material or substance changes size.

In addition, under the same conditions, a transition from one state of aggregation to another is quite possible. As an example, we can take the early spring period, when at night the temperature drops as much as - 10 degrees Celsius, and during the day rises to + 10, due to heating from sunlight. Of course, with such sharp changes the air temperature will change and the temperature of the fuel in the tank will change, which will have a direct impact on So, the density itself will directly affect the readings of the sensors, which will give a large error when measuring the fuel level.

Electronic fuel level gauges, when determining the fuel temperature inside the fuel tank, will correct the fuel level measurement using special correction factors. In the end, the motorist will receive accurate data about how much fuel is in the measured container. In addition, some electronic fuel level sensors use a special function of averaging the fuel level signal in the tank. This function reduces curvature and fluctuations in fuel level values, which are caused by significant differences in fuel in the tank.

The electronic fuel level sensor board can initiate additional pre-processing of the incoming signal, which will filter fuel spikes in the fuel tank itself. Another distinctive feature of electronic fuel level indicators is independent power decoupling, which completely eliminates problems associated with a malfunction of the vehicle’s battery or generator.

All automotive experience in using electronic fuel level indicators on vehicles shows that, in categorical difference from analogue sensors and indicators, the readings of electronic indicators will not change in the presence of metal objects or magnetic fields near the sensor. In addition, changes in the performance of the device cannot be caused by dirt. That is why we can conclude that all electronic fuel level indicators, which have been correctly installed, are the most effective modern method of monitoring the fuel level in tanks.

2. Checking the electronic fuel level indicator.

Problems that arise with the electronic fuel level indicator can be of a wide variety of nature. The most common malfunctions are those in which the device displays incorrect and unreliable data. For example, if the fuel tank is completely full, the indicator will indicate that the tank is empty. There can be many reasons for this malfunction, which cannot be said about solving the problems that arise. It may happen that electronic system froze, the electronic board succumbed to negative influences, etc. In this design, all malfunctions arise for several reasons:

- the electronic board has become unusable;

The device in the fuel tank itself “covered”;

The sensor itself burned out.

To check the normal operation of this device, you need to arrange a test drive. First, you should completely empty the fuel tank, then fill it completely and start driving. If the indicator does not indicate that the tank is full, then the system is malfunctioning. Consequently, it will be necessary to carry out a total diagnosis, since even a minimal malfunction will lead to the collapse of the entire system.

3. Replacing the electronic fuel level indicator.

In order to begin directly replacing the electronic fuel level indicator, you need to determine its location. Often, this device is installed directly on the fuel tank of the car. It is important to note that in most cases, this type of breakdown will require computer diagnostics. If it does not help, then the device should be completely replaced. It is advisable to lift the car and disconnect all the contacts that lead to this device.

Removing the device will not be difficult, but installing a new one will not be difficult. The fact is that before removal you should mark all the contacts that will be included in the new device. In addition, the contacts themselves should also be checked, since the malfunction may be caused by them. Next, you should attach the new device to its rightful place, simultaneously installing all new and old contacts in the desired position. Now all that remains is to check the operation of the device. In addition to filling and emptying the tank, you can simply use an ammeter and voltmeter to measure the current and voltage in the incoming and outgoing contacts. If, nevertheless, the motorist was unable to fix such a breakdown, then he should contact service center, since the entire electronic system of the car could be negatively affected.

Do-it-yourself gas meter diagram for a car

Today I present to your attention truly homemade device. Yet again on a PIC16f676 microcontroller and this time with a dual, dynamic seven-segment indicator. The creators called this device " Backometer" - And it appears digital gasoline level indicator in liters.
The accuracy of the device inspires confidence since it is calibrated directly on a specific car, since the fuel level sensors are the same only by brand.The original source was this website

Device diagram:

Drilling holes for parts

After a couple of hours the device is ready

Microcontroller firmware, crown, and here is the first launch of "Bakometer"

Now you need to make the face of the face. For this you need a couple of screws, just like for installing motherboards into the case and screws for them. The black screws were taken from ASUS motherboards. I collected them once and really liked them, so I installed the regular ones and left these ones as they came in handy.

After assembly, the instrument was calibrated on the bench using a 500 ohm variable resistor. This is enough for clarity, since The resistance of an empty classic tank is about 340 Ohm.
After calibration, the tank meter shows the level of gasoline in the tank according to the firmware. The firmware can be done 0-99 liters.

When the level in the tank drops below 5 liters, the indicator begins to flash, displaying the readings in the tank up to 00 liters. This is clearly visible in the video. And the jump is 35-40 in the video because I calibrated it by eye and the distance on the variable from 35 to 40 liters turned out to be very small. In real conditions this will not happen.
Well, the video itself is an example of work

updated in 23:56 22.10 21:32 29.10.2015

Equipment overview

Operational control of fuel use is one of the most pressing tasks facing enterprises and organizations operating vehicles using internal combustion engines. The use of fuel meters allows a more economical approach to the consumption of fuel materials in relation to the result of engine operation, driving time and distance to the next refueling.

Due to the fact that the fuel tanks of modern cars have a rather complex configuration and different linear dimensions, the use of conventional fuel level measuring instruments is not able to reflect the actual amount of fuel used.

Today, the functioning of an online vehicle monitoring system consists of collecting information using trackers and various sensors. The user terminal (tracker) allows you to determine your location, speed and direction of movement using signals from satellites of the GLONASS/GPS systems. Various sensors are usually connected to the terminal via analog or digital inputs.

The initial data received from the sensors is usually either stored in a local device and then uploaded to a common database upon arrival at the park, or transmitted to the server online, usually via GPRS.

The operating principle of most fuel meters is to monitor the fuel level. Some sensors are more simple, such as float sensors. And some are complex modern technologies, such as ultrasonic.

In addition, fuel level sensors differ not only in design and method of measuring fuel, but also in the type of output signal. It can be digital, analog or frequency. This important characteristic will be discussed in this article.

Fuel level sensor with analog output signal

Due to the most reasonable cost and minimal percentage of error, analog fuel consumption sensors are the most common in the system online monitoring Vehicle. In addition, the production of the equipment itself does not require significant costs and is subsequently easy to operate.

The operating principle of an analog, as well as a standard, sensor is based on the processing of primary data using a microprocessor that produces data in digital format. If we are talking about an analog FLS, then the processor first converts the data received in digital form into analog. However, then, for transmission to the recorder, he again needs to digitize them.

To encode the received information, analog sensors use the value physical quantity, such as current strength and voltage. In reality it might look like this. If volts are used for encoding, then the readings will vary from zero to ten volts. In other words, if the tank is full, the measurement value will be equal to 10 V, and the complete absence of fuel will be expressed as a zero measurement value. Intermediate indicators from zero to ten volts reflect the degree of fullness of the tank, but not as accurately as in the case of a digital FLS.

So, for example, if the equipment outputs a value of “7 V”, this means that the fuel tank fill level is 70 percent. As you can see, no special skills are required from the dispatcher or driver to read the indicators. And yet, such simplicity of analog equipment, according to experts, does not cover its shortcomings due to a significant percentage of the final or real error. What is it about?

Analog fuel level sensor error

The final, or as it is also called, relative error, is the sum of the errors produced by each of the meters and converters included in the fuel level sensor. In conventional analog sensors, at least two meters are installed. One of them is responsible for measuring and transmitting data on the fuel level in millimeters. A second device converts this data into an analog signal for transmission to the receiver.

In other words, the value of the real deviation of the entire measuring route will include the value of the measurement error of level, voltage and conversion, expressed in percentage or liters. As a result, the total error can reach more than 3% of that declared by the manufacturer. After all, sometimes the manufacturer indicates only the bit capacity of the analog converter, without mentioning the accuracy parameters. In the eyes of the consumer, this means that the overall measurement error can be within 0.1%, which will indicate the high accuracy of the measuring equipment.

However, the correctness of the indicators also depends on other characteristics - additional or partial errors (calibration error, measurement error, intermediate calculations, conversion sampling error, error due to aging of elements, nonlinearity error, hysteresis, etc.). As a result, the real deviation from the declared values ​​may be many times greater than the declared 0.1%. How important is this in fuel level measurements? Let's look at it with an example.

Errors of the fuel level sensor “in action”

If we imagine that the sensor recorded a value of 60 liters in the tank, and the real fuel level is 65 liters, then the difference in values ​​is an indicator of the absolute error. Some may argue that such inaccuracy will not affect the performance of the vehicle. Maybe if we are talking about a car with a tank volume of 600 liters. But for a car with a tank of 40 liters or less, a difference of five liters can be significant.

Another situation: when the manufacturer specifies the bit depth of the analog-to-digital converter without mentioning the accuracy parameters. This, for example, may look like this: “ADC - 10 bits with an output value of 0 to 1023 gradations.” For the consumer, this means that about 0.1% will be added to the amount of the main error indicator. But if we add to these indicators a nonlinearity error of 2%, the error of the meter due to the spread of parameters of radio elements, then the final error will go far beyond 0.1%.

It should also be taken into account that ideally the main error is calculated for containers that have an ideal parallelepiped shape, and the measurement is made at two points. However, as we know, ideal forms do not exist, so the error will increase in direct proportion to the discrepancy between the tank and the ideal parameters.

In addition, fuel performance can be influenced by various external factors: wind, pressure, temperature. For example, normally the operating temperature should not exceed +25 degrees Celsius. If the external temperature rises or falls by at least 10 degrees, then the error will increase. Or let’s say that the vehicle is moving at a temperature of minus 25. In this case, the difference between the normal operating temperature of the sensor and the real one will be 50°C. Thus, only the additional error will be 0.5%. If the overall error of the FLS was 0.5%, then it will increase to 0.75%.

Therefore, when purchasing equipment, you need to pay attention to all the errors encrypted by the manufacturer in the wording of the data. Instead of accuracy parameters of 0.1%, sensors with a measuring system error of ±1% look more accurate. Moreover, you should not equip equipment for measuring fuel level with devices with different error limits.

Inconsistency between the ranges of the indicator and fuel level sensor

The next problem with analog FLS is the difference between the input and output ranges in the measuring system, which significantly distorts the final measurement results. For example, let’s imagine that the equipment error declared by the manufacturer does not exceed 0.5 percent. A navigator with an analog input measures voltage from 0 to 30 V. If a sensor with an input signal from 0 to 5 V is connected to it, the error can reach 3%. That is, the accuracy of all measurements will automatically decrease by 6 times!

But if the output signal is from 0 to 4 V, and the total equipment error is about 1%, then the measurement results may be even more distorted. Of course, for vehicles with a large fuel tank this is not significant, but for small cars such a sensor will be at least useless.

Low noise immunity of the fuel level sensor

The measurement accuracy of an analog sensor can also be affected by poor noise immunity. Despite the fact that electromagnetic compatibility experts have developed devices that are resistant to electromagnetic interference arising from operating inside the car mobile phones or radio receivers, the likelihood of error when operating analog fuel meters remains very significant.

The situation is complicated by the fact that the market is filled with analog devices for monitoring the operation of vehicle mechanisms that are not resistant to electromagnetic interference. Of course, for consumers, analog equipment remains attractive solely because of the pricing policy. But during the first check, the user will be faced with the problem of inaccurate measurements, which have a much more noticeable effect than additional errors, and the joy from the low price will be replaced by disappointment from low quality.

How to choose an analog fuel sensor

Analogue type sensors are usually chosen due to their low cost. They are best used in facilities where fluid level fluctuations are kept to a minimum (eg stationary facilities) or where there is access to stable power supplies.

In addition, if the on-board unit does not support the protocol that the sensor uses, or a digital signal, then of course a sensor with an analog output signal will be a solution for monitoring fuel levels. However, the following factors must be taken into account:

• An indication by the manufacturer of the level of the main error (or the sum of errors) displayed in the corresponding marking.
• Conversion error.
• Additional error.
• Output and input ranges.

If you are not limited by the above reasons, and your goal is advanced and high-quality technologies, then you should pay attention to the digital and frequency type of fuel sensors. What are their advantages?

Fuel level sensor with frequency output signal

The operating principle of sensors with frequency modulation of a signal is based on pulse encoding on a communication line. Although the error of such equipment has become noticeably lower, frequency FLS have slower data transmission compared to analog devices. To speed up the exchange of information, an increase in frequency is used, but this entails the need to improve the source parameters.

The occurrence of errors in the operation of frequency fuel level sensors is associated with the need to convert the initial value into a frequency value. In addition, the frequency method of signal transmission does not have the digital signal encoding required at the output. Therefore, devices with a frequency output signal have not received wide recognition both among car owners and in the field of transport logistics.

Although this type of sensor was an intermediate option in the development of standards for transport monitoring systems, it still remains universal due to the absence of serious errors in data transmission.

Fuel level sensor with digital output signal

Digital type sensors are capable of analyzing readings and transmitting information via a digital protocol to a standard receiver that monitors vehicles. In terms of accuracy of information data, digital FLS significantly exceed analogue and frequency fuel meters.

The built-in microprocessor is responsible for the purity of the data, capable of not only reading, but aligning and linearizing the initial measurement values. Thus, the degree of total error is either reduced to zero or is as small as possible, which made it possible to bring the transport monitoring system to a fundamentally new level.

Recent developments have made it possible to create digital sensors in which the indicator input and sensor output are coordinated with each other: both at the interface level and at the protocol level. Thanks to this, the user can instantly receive information in digital form without encoding or conversion.

All data received through digital sensors is different high degree accuracy and noise immunity. Unlike other FLS, digital sensors are not affected not only by the use of mobile devices and radio equipment, but also by external factors such as weather conditions, magnetic fields, dirt, metal objects, etc.

However, when purchasing a digital fuel level sensor, you must remember that errors are still possible. However, it is associated with the primary meter included in the fuel control system, but at the processing stage this minor error is smoothed out.

Some digital FLS have an artificial delay in issuing a change in the fuel level signal. This parameter allows you to equalize the curvature of the parameters that arise due to significant fluctuations in the fuel inside the tank. In addition, many sensors with a digital output signal have independent supply voltage isolation for the on-board network. Thus, digital sensors operate independently from a generator or battery.

Ultrasonic fuel level sensors

An ultrasonic fuel level sensor is an ultrasound emitter, the signal from which is sent to an electronic unit with subsequent digital conversion and transmission to the GLONASS/GPS monitoring system. The emitting device is placed in the fuel tank and during operation, ultrasound, passing through the bottom of the tank and entering the liquid medium, reflects the level of changes in the medium and returns to the emitter. The return time is the determining factor in determining the fuel level.

The ultrasound method is considered the most accurate compared to other methods of monitoring fuel in the tank. In addition, when installing an ultrasonic sensor, the integrity of the tank itself is not compromised, so installing an ultrasonic FLS is justified in cases where it is impossible or extremely undesirable to make additional holes in the tank.

The main disadvantages of FLS with an ultrasonic output signal are: capriciousness, high cost and additional equipment (ultrasound programmer). It is better to entrust the installation of ultrasound FLS to specialists, since without special knowledge and in case of improper installation, reuse of the emitter is impossible.

Question of choosing a fuel level sensor

The scope of application of fuel level sensors extends not only to the field of road transport. In addition to the use of FLS on moving objects, they have become widespread in the field of monitoring stationary tanks for storing fuels and lubricants. However, in any case, using fuel sensors, it has become possible to measure and monitor the following parameters:

• Fuel consumption
• Filling/draining time
• Amount of fuel drained/refilled
• Drain/fill point.

In addition, the use of fuel level sensors will help identify vehicles in need of repair or replacement, discipline drivers, and optimize the refueling of equipment. Analysis of fuel consumption will allow you to determine where it is best and cheapest to refuel along the vehicle’s route. Regardless of whether you are the owner of a large transport enterprise or the owner of a small car, the use of FLS works to save you money. All that remains is to make a choice which sensor you need.

Especially for our readers, we researched the FLS market and conducted them comparative analysis. We have studied specifications devices and found out the average price level for fuel sensors.

The following digital fuel sensors took part in the review:

• Escort TD-500
• SAT-FUEL
• EPSILON EN
• Caliber
• SCOUT PetrolX
• ASK-Sensor
• DUT-E
• Omnicomm LLS-AF 20310

By studying the technical aspects of each device, we learned the capabilities and distinctive features each FLS.

The Micro Line company produces a fuel sensor, the advantages of which are:

• Possibility to select modifications of the FLS depending on the subscriber terminals used.
• Possibility of connecting several FLS simultaneously via one circuit (Digital (K-line interface)
• Remote diagnostics of Digital FLS (from the Monitoring Program)
• Remote update of DUT software
• High measurement accuracy +/- 1% of tank volume due to high sensor resolution, linearity and temperature stability
• Impact-resistant, non-flammable, non-conductive plastic housing
• Dust and waterproof automotive connector
• Easy installation - the FLS does not require calibration after cutting the measuring part
• Wide range of lengths - 0.3 - 3 m.
• Affordable price

According to a representative of the Escort group of companies, FLS can be called one of best options capacitive fuel level sensors in its class.

The fuel level sensor or capacitive level meter "Escort-TD" is a high-precision measuring device developed by the Escort group of companies, which is designed to measure the level of light petroleum products in any tanks (storage tanks), with a maximum filling height of up to one and a half meters.
To meet individual requirements, sensors with a measurement level specified by the customer are manufactured; for example, Escort-TD fuel level sensors are widely used for underground fuel storage bunkers at gas stations, for railway tanks and other large storage tanks. The fuel sensor is used to measure the level of light petroleum products in systems that measure and control the amount of fuel and lubricants in various containers.
The scope of application of the fuel level sensor is automotive and tractor equipment, it is used as a fuel level meter, as well as in various industries to monitor the level of any light petroleum products in any containers and storage tanks.
The Escort-TD fuel level sensor can be installed instead of the standard fuel level sensor with a similar flange, the mounting of which is usual for float-based automobile fuel level sensors in the CIS. The fuel level sensor converts the level into a digital code and transmits the value via the RS-485 interface. The meter has an analog signal output for connection to a dial level indicator and an output for indicating the emergency fuel remaining.

The company positions its fuel level sensors as the best in price-quality combination. Those. For very reasonable money, the integrator receives a universal sensor (4 modes in one + indication on a standard indicator). In addition, the Escort TD-500 FLS has a full package of certificates, exceptional reliability (warranty failure rate 0.4%) and a convenient sensor installation kit. None of our competitors can boast of such a set.

Device of the SCOUT group of companies has more than 15 key advantages, including the following:

• The unique sensor housing is not subject to corrosion and is fire resistant;
• thanks to design features the housing is prevented from deforming when installed on uneven tanks, including round tanks;
• the small size of the case allows the sensor to be installed on most types of equipment;
• the design of the bottom of the housing has cavities and ribs for ideal pressing to the tank, as well as retaining excess sealant;
• The penetration of sealant into the drainage holes is prevented due to the special design of the drainage;
• fastening with 6 self-tapping screws ensures uniform pressure of the sensor body to any type of tank;
• sensor connection connector with protection degree IP66 allows it to be used in direct contact with water and dirt;
• FLS setup and configuration can be done remotely via GPRS - through MT-700 and MT-600 terminals.

The sensor of the SCOUT group of companies was recently announced and is now being tested in various climatic zones. After completion of field tests, in June of this year SCOUT Group plans to begin point partner testing of the device.

TKLS company fuel level sensor "TechnoKom" was recently announced and has not yet gone on general sale. Based on the presented characteristics, it is clear that this is a fuel level sensor with a large number of modern functions, such as remote program updating and configuration, auto-calibration and self-diagnosis.

Fuel level sensor SAT-FUEL from the company Satellite Solutions It does not have any special advantages over competitors, and at the same time, in terms of functionality, it is not particularly different from sensors from other manufacturers.

IN DUT group of companies "Ultra" EPSILON EN has introduced new solutions that expand the capabilities of this sensor. The EPSILON EN sensor provides modifications with frequency, analog, and digital inputs RS-232, RS-485.

Main advantages of EPSILON® EN:

• modular design (the measuring head is mounted and dismantled independently of the fuel probe, which allows, if necessary, to easily and quickly change the measuring head without re-calibrating the tank); the presence of an inclinometer (allows you to significantly increase the accuracy of measuring the fuel level when operating in rough terrain);
• the presence of a built-in concentrator (the ability to measure the total volume of fuel in vehicles with several tanks);
• electronic galvanic isolation built into the sensor; explosion protection level lEXiallB without an external spark-proof barrier in the basic, extended and simplified modifications.

FLS "ASK-Sensor" from the company "Automated control systems" has the following differences from its competitors:

• Low price
• Quality control at all stages of production
• Modular design - if one of the sensor elements fails, not the entire modular design is changed, but only the faulty element (replacement occurs without re-calibration of the tank), thereby eliminating additional costs
• The fastening bolts are closed and sealed with special seals. seal – access to the sensor mounts themselves is prevented
• Vibration resistant
• Explosion-proof
• The cable is protected by metal corrugation
• Measuring head protection IP68

Company "Technoton" produces the DUT-E FLS, which has the following distinctive features:

• thermal correction with an adjustable coefficient allows automatic correction of measurements based on temperature environment*;
• DUT-E self-diagnosis allows you to control the reliability of data*;
• certified for compliance with mandatory automotive standards of the Russian Federation, Belarus, and the EU;
• shortening without the need for calibration (models A5, A10, F);
• extension of length using additional DUT-E sections – up to 6000 mm*;
• ergonomic bayonet mount of the sensor allows you to save time on installation;
• sealing holes to prevent unauthorized interference in the operation of the sensor;
• The delivery kit contains everything necessary for installation and connection (connecting cable, mounting plate, rubber gaskets, screws, seals);

* – DUT-E 232, DUTE 485.

conclusions

The comparison table contains all the main characteristics of fuel level sensors. The table shows that all sensors are at the same level in terms of the main parameters of accuracy and operating parameters. However, there are some models that differ in the presence of an inclinometer and explosion protection function.

According to the information from the table, it can be seen that the average price level for FLS is in the range of 6000-7000 rubles. At the same time, an increase in the price of sensors from manufacturers that have been on the market for a long time and have proven their products as one of the most reliable is monitored.

Comparative table of FLS characteristics