Dashboard. Speedometer and odometer - what's the difference

In the world of every minute changes and perpetual motion, you have to constantly monitor the speeds and distances traveled. As the March Hare said in Lewis Carroll's tale, "you need to run as fast just to stay in place, and to get somewhere, you need to run at least twice as fast." Cyclists also want to keep up with the times. That is why not only professional athletes, but also amateurs are in a hurry to acquire such a device as an odometer for a bicycle.

What is an odometer

A bicycle odometer is a device needed to measure the number of revolutions of the wheels while riding. Modern odometers accurately determine the total mileage of a bike, helping the owner to correctly imagine the capabilities of his vehicle. The device displays both daily and total mileage of the bike.

How it works

Different odometer types have different designs, but the underlying operating principle is the same. The following parts of the device can be considered functional:

• counter (responsible for calculating the number of wheel revolutions);
• a controller that fixes the revolutions (it is directly connected to the counter);
• indicator that reflects the numerical indicators of the traveled mileage on the display of the speedometer.

In mechanical odometers, the force to the cable is transmitted from the drive wheel in close contact with the bicycle tire.

In odometers with electromechanical transmission, the impulse is transmitted via a cable using a sensor to the electronic panel. Electronic models function by receiving electrical impulses.

How does it work

Regardless of the speed at which your vehicle is moving, its wheels make a certain number of revolutions, passing a kilometer. This indicator remains unchanged. Knowing the number of wheel revolutions, it is easy to calculate the number of kilometers traveled and display it on the counter. Counting and transmission occurs differently in different odometer types.

There are three types of odometers:

• mechanical;
• electromechanical;
• electronic.

Older and gradually receding mechanical models function with a special flexible cable that rotates at the same speed as the wheel. The rotation is transmitted by the output shaft, then the force goes along the cable to the magnetic arrow. The magnetic needle displays a numerical value on a magnetized disc.

Quite simple in terms of configuration, mechanical odometer is relatively cheap. It is easy to disassemble and repair, replacing old parts with new ones. Its work does not depend on batteries and magnetic storms. Meanwhile, with proper installation and configuration, such a device copes with its main function of elementary calculation of kilometers with dignity.

The disadvantage is the automatic zeroing of the readings upon reaching a certain threshold figure. In addition, the mechanical device slightly complicates the rotation of the wheel, and if the wheels are bent by an eight, it does not work at all. It can affect the meter readings and dirt that gets on the device. So such an odometer must be wiped and lubricated frequently and thoroughly. But for walking on a clean and smooth highway, a device with a mechanical transmission is quite suitable.

Electromechanical odometers work due to the rotation of a gear, which leads a force to an electromechanical sensor.

The sensor device produces pulses of electricity that travel through wires to the speedometer unit, where a small electric motor rotates to drive the mileage counter. Odometers of this type are installed on most modern cars.

Electronic odometer sensors are completely electronic. In addition, they have liquid crystal displays. It is more difficult to "cheat" such a device; this will require a special device.

Modern bicycle odometers, in fact, are becoming part of the "on-board" bike computers, which calculate not only the total mileage of the bike, but also many other parameters of movement that are necessary for cyclists who are seriously involved in cycling. These can be, for example, indicators such as:

• current speed;
• average speed;
• distance length;
• travel time;
• cadence;
• mileage;
• clock.

The electronic odometer sensor is a contact, hermetically located in the case, - a reed switch. It is fixed on the front fork stays or (when the length of the wires is sufficient for this) near the rear wheel. A permanent magnet is attached to the spoke of the wheel and triggers the sensor. The microcontroller monitors the time between the two closest sensor turns on. Liquid crystal displays with seven segments reflect the obtained result, the backlight function is performed by LEDs.

Are there any errors in the operation of bicycle odometers?

As with any instrument, the odometer can have an acceptable percentage of errors. Mechanical devices mounted on mountain bikes or bicycles moving on rough terrain can give up to 15% errors. It is believed that the more severe the operating conditions of the vehicle, the higher the error. For example, slipping, loosening of the flexible cable (it must be stretched, should not be allowed to sag in the loops), loosening of parts can adversely affect the operation of the odometer. True, such a high distortion rate is still not typical for new generation bicycle odometers. Electromechanical devices can give up to 5% distortion. But digital gadgets, in which there are no mechanical connections between parts and the risk of internal damage is minimized, give no more than 1% of errors.

How to choose the right device

If you have clearly decided that you need a bicycle odometer and will not become another toy dangling idly on the handlebars, before installing, first of all, you need to choose a high-quality device that you will not have to throw away after the first cycling season.

When choosing an odometer, you need to take into account such parameters as:

• device reliability;
• limit of indications;
• case quality;
• functional;
• type of attachment.

The most reliable bike counters are produced by companies such as VDO, BBB, Cateye, Sigma. You can choose a model individually, based on the goals that you set for yourself.

Odometers are divided into models with a maximum speed of 99.9 km / h and devices that display three-digit indicators. For example, the Sigma 506 speedometer shows speeds above 100 km / h. This device is designed for cyclists. It is hardly useful for amateurs.

In terms of size and compactness, devices can be different, but the functionality does not depend on this. You can even purchase a device in the form of a wrist watch that measures the heart rate of an athlete.

You can also mount the bike computer on or on the steering wheel itself. There are devices with a universal mount.

An ideal odometer model should have a large display with clearly readable numbers.

The instrument must be able to withstand vibration and harsh weather conditions, and its components must be of a quality built.

How to set up an electronic odometer

To start installing a bike computer is, first of all, to correctly specify the parameters of your vehicle. This is best done immediately after purchasing the bike. The metrics are best recorded and saved.

1. First you need to set the indicator C - the length of the wheel. It needs to be clarified, since this number is non-standard. To do this, measure the perimeter of the tire using a measuring tape wound around the wheel in a circle. Another way is to put a bright mark on the wheel with paint and, after rolling the bike one wheel revolution, measure the distance from one print to another.
2. Then you need to fix the sensor on one of the fork feathers or on a bicycle frame using electrical wiring.
3. Next, we wrap the wire tightly around the feather and the brake cable.
4. We install a mounting plate on the stem or the steering wheel.
5. We fix the magnet on the spoke, but do not overtighten the screw so as not to break the magnet. There should be no more than 3 mm between the magnet and the sensor.
6. We fix the bicycle computer in the contact area and check the quality of work.

A bicycle odometer is a must-have device for every modern cyclist. With the skillful use of the device, it is possible to predict the timing of maintenance in a timely manner, correctly distribute sports loads, and comfortably travel long distances in a cycling environment. A well-chosen and reinforced odometer makes life on two wheels easier and increases your chances of not standing still.

Many motorists are interested in the question: odometer - what kind of device is it and what is it intended for? Modern cars are equipped with many different devices and devices, so it can be difficult to understand the purpose of all devices. In this article we will tell you about the device and the principle of operation of the odometer, its varieties, as well as errors.

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Odometer Description

So what is an odometer in a car and what is the difference between it and a speedometer? Consider the description of the device, let's start with its design and purpose.

Device and purpose

An odometer is a mechanism designed to measure the number of revolutions of a vehicle's wheels while driving. That is, this unit allows you to measure the distance traveled by the machine. Odometer readings are shown on the dashboard of the car - this is the total mileage of the car and daily. In particular, these two scales are located on the speedometer itself.

We figured out what the device is, now let's move on to its design.

The device device includes:

• directly the counter itself, designed to read the revolutions of the vehicle wheel;
• a controller directly connected to the counter and recording revolutions;
• indicator located on the speedometer and showing the mileage traveled by the vehicle.

Operating principle

Now let's move on to the principle of operation. The device itself is either a mechanical (depending on the type) or electronic device that allows you to accurately determine the number of revolutions that the wheel carries out. These data allow the driver to determine the mileage traveled - that is, the total mileage of the car for its entire operation, as well as the mileage for a certain time period. The data that the motorist ultimately receives is displayed numerically on the dashboard, namely in kilometers.

This is the principle of operation - a vehicle wheel makes a certain number of revolutions for each kilometer traveled. Moreover, this indicator will always be the same. If you know exactly how many revolutions the wheel has made, it is quite possible to calculate the distance traveled, which is shown on the counter.

If necessary, the driver can always reset the information on the odometer (daily mileage) if it is necessary to determine the distance from one point to another. This also allows you to find out the fuel consumption of the vehicle. Naturally, if the odometer does not work, it will be problematic to determine this.

Kinds

It is not difficult to wind or twist the mileage of a car. This is confirmed by multiple photos and videos that can be found on the net. Twisting a car's mileage increases its value in the market, so rolling is a common practice among dealers. But in order to wind up and twist the mileage, you need to know exactly what type of device is used in the car.

The odometer programmer must be used according to the type of instrument. And the type of device, in turn, may differ depending on the model of the vehicle, its year of manufacture.

In total, three types of devices are distinguished:

1. Mechanical - this type is one of the oldest. The odometer can be rolled using any twist. The rotation of the car wheel is counted using a counter, in particular the mechanical component. Under the action of mechanical forces, the meter reads the revolutions and converts them into kilometers.
2. Electronic and mechanical devices - This is a more advanced version of the above devices. In this case, odometer correction is carried out using CAN-rotors. The counter reads the revolutions of the wheel using mechanical links, but later all this information is converted into signals. As a result, the data will go to the dashboard.
3. Digital option on the microcontroller is currently the most modern. In this case, all the necessary indicators are read and converted into visible parameters in digital form. Correction of the speedometer in this case is made using special equipment, since such a device is usually a component (video author - BORAVTO Group of Companies).

Instrument errors

Almost any modern device works with an error. Today there is a certain standard of errors, for example, for mechanical devices it is 5%. If the vehicle is used in harsh and different conditions, this parameter can be increased up to 15%. It takes into account the wear of various components and parts of the car. For example, wheel slip.

Formally, the vehicle is moving because the wheels are spinning, but in fact the car is in place. In addition, clearances, weakened springs in the structure, loosening of the cable or poor adhesion also affect the readings of the device. Electromechanical devices read the signals that come from the speed controller per unit of time. In this case, the error will be lower and the accuracy will be higher. In fact, electromechanical instruments rarely provide data with more than 5% inaccuracy, even if the car is old enough.

As for digital instruments, they are the most accurate of all, since in this case mechanical connections are not involved. But such devices may have an error directly related to wheel wear and replacement (video by Ilya Grigoriev).

Main aspects

As we have already said, odometer winding is a common procedure, in particular, during pre-sale work. Correction of odometer readings makes it possible to demand more money for a car, which, of course, is beneficial for every car owner who decides to sell his car. In order to accumulate mileage, special equipment is even used to correct odometers, for example, a 5 pro spinner. But how to understand that manipulations have been carried out with the device?

Mechanical

How do you know if the mechanical type odometer has been corrected? In this case, winding up the odometer can be carried out even by a motorist who has no experience in this process. If the odometer was adjusted with your own hands, it will be quite difficult to identify this later. But the car owner can always diagnose the device drive attachment. If the place of fixation itself is clean, then this means that everything is fine with the device, but if dirt is visible around it, then this indicates that the nut was unscrewed at one time.

Electromechanical

The odometer corrector will allow you to easily rewind the readings of an electromechanical device, for this you need to open its case and disconnect the gears. If you notice that the integrity of the joints has been violated, and traces are visible on the fasteners, then this indicates a possible unwinding of the readings.

Electronic

An odometer calculator can also be used for an electronic device. Traces of interference can be identified by violation of the integrity of the case.

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Video "How to determine if the run has curled?"

You will learn more about this from the video below (the author of the video is SULTAN).

Each car owner will confidently answer you that he has already studied his "iron friend" and knows him inside and out. But if you ask them what an odometer is, not everyone will answer. And, by the way, this device plays an important role in the life of any car. So let's figure out what an odometer is, why is it needed, how to decipher the indicators and everything related to this mysterious device.

An odometer is a device for recording the number of kilometers traveled by a vehicle in a certain time.

First of all, let's indicate what is the difference between the odometer and speedometer devices, since many people confuse them with each other. This is due to the fact that the speedometer and odometer are located close to each other on the instrument panel. In addition, the design of any car is based on the fact that these two devices have one drive. So what's the correct speedometer or odometer? A speedometer is a device whose main function is to show the speed of a vehicle. Unlike it, an odometer is a device for recording the number of kilometers traveled by a vehicle in a certain time. Simply put, the odometer works by counting the number of revolutions of a car wheel.
It should be noted that two indicators of this device are displayed on the dashboard of the car. One is the total number of kilometers traveled by this vehicle, the second is the so-called daily odometer. Each of them has its own purpose.

Functional properties of the device

Modern electronic odometer

Many novice drivers have a question, why even have an idea of \u200b\u200bhow much mileage your car has, are these numbers really so important? Extremely important.
Odometer readings showing total mileage are taken in such cases:

It is possible to reset the odometer readings exclusively for the daily option, the total mileage is not reset.

• ... The numerical indicators of the kilometers traveled serve as an identifier for the technical condition of the chassis and the vehicle as a whole;
• fuel consumption. By zeroing the readings of the daily device and filling the tank of the car, you can determine the fuel consumption per 100 km of run;
• the exact distance between two settlements.

As for the results of the daily odometer, then its readings will be useful for drivers whose salary depends on the vehicle's mileage.
Please note that you have the opportunity to reset the odometer exclusively for the daily option, the total mileage is not reset.

Understanding the variety

There are several types of devices that differ not only in structural parts, but also in measurement accuracy:

• mechanical. The first, simplest devices, the results of which have the greatest measurement error - 3-5%, worn-out devices can give an error of up to 10%;
• mixed (electronic - mechanical). A hybrid version of odometers, in which the values \u200b\u200bare still obtained mechanically, but are converted and displayed on an electronic display. The percentage error for such odometers is about 5%;
• electronic. Fully electronic devices with the least distortion of results. Even with long-term operation, the error of the car's odometer is no more than 2%.

Distortion of real indicators

Rolling back odometer readings with a drill

Devices for changing the results of the run are popularly called "twists"

As mentioned above, the odometer reading is an indicator of the condition of the vehicle. There are situations in life when it is necessary to correct the results of the device after replacing large vehicle components. Unfortunately, unscrupulous sellers often use twisting of the device, changing the odometer readings to reduce the real mileage of the car. True, there is also such a thing as "winding the odometer", when the results are winding up.
The easiest way is to change the results with a mechanical odometer, here it is enough to remove the cable of the device from the gearbox, connect an electric drill or an electric motor to it, and then “rewind” the indicators to the desired result. This way of twisting the odometer is also suitable for the hybrid version of the device.
The electronic odometer is not so easy to change, since it is part of the machine on-board computer and the readings are transmitted not only to the display, but also to other vehicle control systems.
So how do you reset an electronic odometer? For this, there are both special programs and devices for twisting.

"Spinners" to correct the results of the run

Devices for changing the results of the run are popularly called "twists". There are several types of them, and can be used not only for odometers, but also for speedometers:

• for mechanical devices, Hall effect devices are often used. They are connected via a cigarette lighter and are relatively inexpensive;
• equipment for correcting the odometer via obd 2 or CAN - bus, corrects not only the odometer itself, but also the memory of all devices on your board connected to the speed sensor. The principle of operation is simple - connect the device to the required connector and turn on the ignition.

It should be noted that adjusting the odometer with your own hands will give a result if you carefully read and follow the instructions for the device.

We program the device

Odometer Corrector Digimaster

In addition to the equipment, there are also a number of programs that allow for correction. The most common option is an odometer calculator, which calculates speed based on wheel size, crankshaft RPM and gearbox gear. For cars of the brands "Hyundai", "Ford", VAZ, "Mazda", "Toyota", "Kia", use the Stool program to correct odometers. It is also possible to correct the odometer using - this is an adapter (universal) required to work with twisting programs. Note also the Amprog odometer programmer and the Digimaster II odometer corrector.

There are many ways to change the readings of the electronic odometer from special programs to correctors-programmers.

For those who prefer to buy complex options, the best way out is to buy software 5 PRO odometer programmer. It includes:

• programmer;
• adapters USB-PO5, BDM-PO5, EEPROM-PO5;
• scheme for restoring instrument combinations MS-1.

The choice of the program and adapters depends on the brand of your vehicle, the type of device, and financial capabilities.

Odometer breakdown

Odometer not working, it is not pleasant and very troublesome. If you bought a car with a device that is no longer working, carry out a full vehicle diagnosis. This way, you will save yourself from unforeseen road situations in the future and, of course, make repairs to the odometer. You can carry out this action, both independently and using the services of professionals.
Self-repair must be carried out very carefully, since the slightest mistake will lead to incorrect operation of the device. Even a mistake in improper installation (if you change the fixing screws in places) can lead to distorted results. True, in most cases this refers to the mechanical versions of this device. Not confident in their abilities - contact the technical service.
You learned what a car odometer is, studied the concept of "odometer readings", what it is and how to decipher them, familiarized yourself with programs, as well as devices for correcting results. We hope that our information was useful to you.

“Yes, I don’t need to explain anything, I have 100 thousand kilometers on my speedometer,” - you can often hear this phrase among those arguing about cars. But the formulation of the thought is completely wrong. If you analyze the speedometer and odometer, the difference is obvious. It is the odometer that shows the mileage of the car, while the speedometer determines the speed of movement.

Deep in history

The oldest odometer dates back to the first century. The Greek mathematician Heron became the parent of this invention. The device was in the form of an ordinary trolley, the wheels in which were matched with a special diameter. The wheels were turned exactly 400 times in 1598 meters (milliatrium). set in motion the simplest mechanism. Small stones that fell into the tray served as an indicator of the run. To calculate the distance traveled, it was necessary to count the number of stones dropped. Since then, people have stepped forward in their inventions, but the idea itself was ideal.

The speedometer and odometer, the difference between which is not only in the readings, have different dates of invention. The speedometer was invented a little over a hundred years ago. For the first time such a device was installed on an Oldsmobile car in 1901. For ten years, the speedometer was installed only as an option and was considered a curiosity. Later, factories began to install it as a mandatory device. In 1916, the speedometer underwent improvements that were made by Nikola Tesla. It has survived to this day in almost the same condition, apart from some modern additions.

What is an odometer? Device and purpose

So, every motorist should know what a speedometer and odometer are for. The difference between these devices, of course, exists. Let's look at the odometer first. What role does it play in the toolbar? An odometer is a mechanism that is designed to measure the number of revolutions of a wheel while a vehicle is moving. In other words, it is a node that enables us to know the distance traveled by the car in kilometers. Odometer readings can be read from a special device on the machine panel. The odometer shows both daily and total mileage. These two scales are often located on the speedometer itself.

The odometer design is simple and includes the following components:

• The counter itself, showing the number of revolutions of the wheel of your vehicle.
• A controller that records the revolutions and is directly connected to the counter itself.
• Indicator displayed on the speedometer. Demonstrates the distance traveled by the car in kilometers.

How the odometer works

Many novice car enthusiasts often hear the terms "speedometer" and "odometer". The difference between these devices is not known to everyone. What is an odometer, we figured out, and now about the principle of operation of the device, how it functions. An odometer is an electronic or mechanical device that allows you to accurately determine the number of revolutions that a wheel has made. Such data enable the driver to determine exactly how many kilometers his car has traveled over the entire period of operation and more. You can also find out how much the car has traveled in a given time period. The data is displayed numerically on the odometer display in kilometers.

This is the essence of the odometer - the wheel of the vehicle for each kilometer of the distance traveled makes a strictly defined number of kilometers. This indicator is always the same. Knowing how many revolutions the wheel has made, the counter calculates the distance in kilometers.

If the driver has a need to determine the distance traveled from point A to point B, then he can always reset the counter. Thanks to this action, it is also easy to notice the fuel consumption for a certain path. Naturally, with a non-working odometer, such an operation is simply impossible to do.

Odometer types

Considering the odometer and the speedometer (there is a difference between them in the structure), we will determine the types of odometers. There are three main types:

• Mechanical. The oldest type, its progenitor, was invented by the ancient Heron. If you need to wind up such an odometer, you can do it with any twist. With the help of a digital counter, the rotation of the wheel of the mechanical component is taken into account. Under the influence of mechanical forces, the counter reads the revolutions and converts them into kilometers. The disadvantage of such counters is that when a certain figure is reached, the readings are automatically reset to zero.

• Electronic-mechanical device... More advanced odometer model. To correct such a counter, the use of CAN-rotors is already required. In this case, the wheel revolutions are read by the counter using a mechanical link, and then the information is converted into signals. The data is digitally displayed on the dashboard.

• Digital odometers... They operate on the basis of a microcontroller. The most modern device. All the necessary indicators in this case are read in digital format. To correct such an odometer, special equipment will be required. The digital odometer is part of the vehicle's on-board computer.

Odometer error

Everyone knows that any modern devices in their work have any inaccuracies. There are some standards that allow for errors. For mechanical devices, for example, this figure is allowed at 5%. If the vehicle is operated in any harsh conditions, then this figure can increase up to 15%. In such cases, there is a discount on the wear of various parts, vehicle units (for example, slipping). Formally, in this case, the wheels rotate (supposedly there is a movement), but the distance in kilometers does not increase.

A certain error in operation can be shown by both the odometer and the speedometer (the difference between these devices is now clear). Also, the readings of the device are affected by various clearances, loosening of the cable, poor adhesion, weak springs. Electromechanical devices read the signals indicated by the speed controller for a certain period of time. In these cases, the error is lower, the accuracy is higher. Cars with electromechanical devices, even very old ones, rarely give an error of more than 5%. Digital instruments are the most accurate, no mechanical connections are involved. If such devices have an error, then this is directly related to wheel wear.

What is a speedometer

A speedometer is a device that measures the movement of a vehicle. Meter readings are displayed in km / h (kilometers per hour) or, in America, in miles per hour. There are two types of speedometers: mechanical (analog), digital. How does the speedometer work and what does it show? In a rear-wheel drive vehicle, the speedometer monitors the rotation of the output shaft at the gearbox, in this case the speed is calculated from it. Accordingly, the speed reading will depend on the size of the tire, from the rear axle, as well as on the inherent error of the device. For front wheel drive vehicles, the speed is measured using the left wheel drive. The rounding of the road is added to the speedometer error. We examined above the odometer and the speedometer (the difference is what they are for, the principles of operation). Let us now find out the reasons for the errors of the speedometer.

Why is the speedometer lying

If you look at the speedometer of a car, it's not hard to guess why he is lying. Why does it show the speed exceeded? First, the driver is less likely to violate the speed limit and receive a fine. Secondly, if the speedometer indicated a lower speed from the real one, then, most likely, the drivers would not stop suing the automakers, proving their innocence of speeding. Does the speedometer have to lie? The fact is that it is most difficult for this device to indicate super-accurate readings, because the speed depends on the rotation of the wheel, on its diameter, and this is a very unstable parameter.

The error of the speedometer at a speed of 60 km / h is very minimal, it is practically nonexistent. At a speed of 110 km / h, the error can be 5-10 km / h. If the car reaches a speed of up to 200 km / h, then the average error value can be up to 10%. We have answered your question "what is an odometer and a speedometer". The difference is now clear. Let's summarize. All of the above makes it possible to draw the following conclusions.

Odometer and Speedometer: Instrument Difference

As already mentioned, not all car enthusiasts understand the difference between two different devices - an odometer and a speedometer. Some are misled by the fact that the odometer is directly integrated into the speedometer itself. That is why many refer this design to one device. What is odometer and speedometer? The difference between the functionality is obvious. Confusing these devices is simply unacceptable. In short:

• The speedometer shows the speed of the vehicle.
• The odometer indicates the distance traveled in kilometers.

Their functionality is not interconnected in any way. The combination of these two scales is not determined only by the convenience for the driver's perception. However, modern displays this information on the display among the main information.

Why twist the run

“Twisted the speedometer to reduce the mileage” is also a misnomer among motorists. We told you what the odometer and the speedometer are for. The difference and the photos of these devices indicate that to reduce the mileage, the readings are not twisted on the speedometer, but on the odometer. Why do they do it? Everyone justifies these desires in different ways. Device malfunction, replacement of the entire panel, riding on non-standard tires. To be honest, there is practically one reason - everyone wants to "rejuvenate" their vehicle. This often happens when a car is sold. There are those who, on the contrary, want to increase the mileage. Often these are drivers of commercial vehicles who use their cars for business purposes. Indeed, very often the fuel consumption exceeds the norms admissible by the accounting department, which do not take into account depreciation, wear and tear of the vehicle. To compensate for these costs, drivers go for such a trick as increasing the mileage.

All vehicles have an odometer. Every car enthusiast knows what it is. However, not everyone knows the device of this device, the principle of operation, malfunctions and repair methods. In addition, modern cars are equipped with electronic equipment that is difficult to deal with. Let's take a look at everything related to odometers.

Purpose and device

What is this device? This is a special mechanism that is designed to measure the number of revolutions of a car's wheels while driving. In other words, this element allows you to measure the distance traveled by the car. Odometer readings are displayed on the car dashboard. The device shows the driver daily as well as total mileage. Both of these scales are located directly on the speedometer unit.

So, the purpose of the odometer is clear. Now we need to move on to the design of the mechanism. This device consists of a counter, which is designed to count the number of revolutions of a car wheel. The device also has a special controller. It is directly connected to the counter and is required to fix the revolutions. Finally, there is an indicator. The element is located on the speedometer and directly shows the driver the kilometers traveled.

Operating principle

Now we should move on to how the odometer works. What it is is already more or less clear. The principle of operation of this measuring device is highly dependent on the type of device. It can be an electronic odometer or a mechanical one. So, a car wheel makes a certain number of revolutions in the process of passing each kilometer. Moreover, this indicator is always the same regardless of the speed of the machine. If you know exactly how many revolutions the wheel has made, then you can easily calculate the distance traveled in kilometers (or miles for American cars), which is shown on the counter. The oldest mechanical gauges operate on a flexible cable. The latter rotates at the same speed as the wheel. This rotation is transmitted from the gearbox output shaft. The cable transfers forces to a drum counter installed in the car's dashboard. The device has five reels with numbers.

They are connected to each other by a worm gear. The cable itself is connected to the first drum through a gearbox. Mechanical devices are good because the repair of an odometer of such a plan is not complicated and will require replacement of worn parts.

How is it useful?

It would seem, how can this small device counting kilometers be useful for a car owner. But in fact, the role of the odometer in the life of a motorist is quite large. This is an important tool, using the readings of which, determine the moment of machine maintenance, oil change, valve adjustment, timing belt replacement, camber check and other operations.

The instrument is the best indicator of the condition of the vehicle. After all, it is not just that experienced motorists, buying a car from their hands, are interested in the mileage. Based on this, some unscrupulous sellers have learned to reduce the number of kilometers traveled. Therefore, when buying a car in the secondary market, it will be useful to conduct a small test drive. It is necessary to observe the speedometer needle during the trip. If the odometer moves jerkily, with jamming, the speedometer needle does not move smoothly, then the mileage has been changed. The seller rolled up the odometer before selling. Sellers know very well what it is, so there are practically no honest runs on the secondary market.

How to use a daily counter?

With this device, the driver can accurately determine the fuel consumption of the vehicle. Sometimes it may seem that the engine has begun to consume too much. In this case, you should not immediately go to the service station and make a diagnosis. First you need to accurately determine the fuel consumption. They put a can of gasoline in the trunk, wait until all the fuel in the tank runs out, then reset the daily counter to zero, pour gasoline from the canister and drive the car as usual until the tank becomes empty again. Then it remains to divide the number of liters by the total mileage of the daily counter, and multiply the result by 100.

In this simple way, you can get an accurate figure for fuel consumption. Knowing the information about how much the car "eats" the fuel, you can calculate exactly how much gasoline poured into the tank will last. Experienced motorists recommend resetting the daily counter after every refueling. You can also determine the mileage for a certain time or the distance between different places on the track.

Odometer designs of different types

This element is a dial. But this is only part of the device. On the secondary shaft of the gearbox, there is a gear that meshes with the gear of the counter drive. This part is connected by a flexible cable to the unit that is responsible for the speedometer-odometer. Mechanical devices are among the oldest. You can twist the mileage on these with the help of any devices that can rotate. The counter counts the revolutions, which means that with the help of any electric motor you can either twist or wind the numbers on the counter. Electromechanical meters are systems based on the same gear on the secondary shaft of the gearbox (it doesn't matter if it's an automatic or a manual transmission).

But it already drives the electromechanical sensor. The sensor generates electrical impulses that go through wires to the speedometer unit, where a small electric motor rotates according to the frequency of their arrival - the drive of the mileage counter. Most cars, including modern ones, are equipped with this device. Odometer correction is carried out here using CAN devices. Electronic odometers differ from electromechanical odometers in fully electronic sensors and LCD displays. They are widely used in cars and trucks. Their distribution is due to the fact that it will be difficult to correct the odometer of such a plan. However, now this is not a particular problem. Correction is carried out using special devices.

Odometer Sensor Types

Impulse sensors based on the Hall effect are used.

Also induction-type devices are used, operating on the principle of electromagnetic induction. Combined systems are used in mechanical elements. This is a gear sensor, which is connected to the output shaft of the gearbox, and is pulse.

Odometer and errors

Almost all measuring devices have errors. Odometers are no exception. Now there is a certain standard for errors. For mechanical equipment, it is no more than five percent. If the vehicle is used in harsh conditions, then the error rate increases to 15 percent. Tough conditions include slipping. The car seems to be moving, because the wheels rotate, but itself remains in place. In addition, the level of error is strongly influenced by clearances, weakened springs in the structure, weak cable, poor adhesion. The readings of the VAZ electromechanical odometer are read from the speed controller. In this case, the error will be very low. It is worth noting the high reliability of the devices. Such devices rarely produce a figure whose error is higher than 5%. The electronic odometer is one of the most accurate.

The design does not provide for any mechanical connections between the components. However, there is also an error here. It is often associated with wheel wear or replacement.

Summary

So, we found out how the odometer works, what it is and what types it is. This is the right thing in the car. You can do a lot with it. The odometer allows you to accurately determine when to change the oil, and will also help determine fuel consumption.