A odometeralso called surveyor or odographis a device that measures the distance traveled by a moving object. They are used in vehicle odometer and for measuring distances in surveying, ergometry, road safety and other industrial applications.
Next we will see how mechanical odometers and digital odometers work. The description will be made for the vehicle's odometer, but the operating concept is the same in other applications.
The mechanical odometer
Every time one wheel makes a complete turn distance equal to its perimeter. Therefore, by counting the number of laps, the total distance traveled can be known exactly.
A mechanical odometer It basically consists of a series of gears with numbers on their edges that are embedded in a wheel or communicate with it through a series of cables.
The gears are perfectly calibrated so that they move at a certain speed according to the wheel turns and show the number corresponding to the distance traveled. expressed in the unit in which the odometer was calibrated (kilometers, miles, etc.).
Usually the mechanical odometer has several teeth and each one moves at a different speed.
For example, there may be three gears, one moving every 10,000 m (10 km), another every 1,000 m (1 km), and one every 100 m. If this odometer reads 252, it would mean that you have traveled 2×10000 m + 5×1000 km + 2×100 m, a total of 25 km and 200 m.
The marker is usually displayed so that it directly shows the total number of km. In the example above it would show 25.2 km.
Most mechanical odometers on vehicles with a certain number of years top out at 99,999 km. At that point it rolls over to 00,000 and they carry another counter that indicates the number of times the odometer has maxed out.
Mechanical odometer gears can be manipulated manually and mask a vehicle's actual mileage, which has been a traditional fraud in the world of used car buying and selling.
digital odometer
The electronic or digital odometers record the distance traveled using a computer chip. The mileage reading is displayed on a digital display and the total mileage value is stored in the main electronic module of the vehicle.
Due to this operation, it was thought that digital odometers would put an end to mileage fraud, but this has not been the case, since a way has been found to alter these values directly in the vehicle's computer.
odometer fraud
Many factors influence the sale price of a second-hand vehicle, but one of the most decisive is the number of kilometers it has traveled. If all other features are the same in two vehicles, the one with fewer miles will be more expensive.
For this reason the manipulation of odometer measurements has been a widespread practice and is known by the English word clocking.
Clocking on a mechanical odometer is a fairly simple task. Simply remove the odometer, move the gear system until it displays the desired value, and place the odometer back on the vehicle.
Unsuspecting buyers can pay much more than the real value of the car and discover the fraud over time. With the advent of digital odometers it was thought that fraud would be drastically reduced. But the reality is that, with legal calibration tools, they can be manipulated even more easily than mechanical odometers.
Tips
Every time a car changes hands, the new technical file or ownership document reflects the mileage at that time. If the car is semi-new, with 30 thousand km or less, it should still have the original tires.
On older vehicles with low mileage that makes you suspicious, the first thing to do is check the wear of the accelerator, brake and clutch pedals.
Also ask for invoices or proof of maintenance checks. These receipts usually show the number of kilometers that the car had at the time of the review. For example, kilometers at which the oil was changed or the brake system was serviced.
If the odometer is mechanical, the numbers should line up perfectly. If they are misaligned or move easily when tapping on the panel, it has most likely been tampered with. If you have doubts that you cannot clear up, it is best to go to a professional service to check the vehicle and issue a report on the condition of the engine and general mechanics.