Accidents accompanied by body repair are a headache for buyers who purchase cars in the secondary market. Identify signs of repainting, puttying and replacing parts will help a professional car paint thickness gauge.
Thickness gauge: what is it and what is it for
Thickness gauge for cars - a device that measures the thickness of the paint on the surface of the body. It is used to determine the number of layers of paintwork and the presence of hidden defects of the machine. The accuracy of the measurement of the device depends on its type and principle of operation.
Classification
Thickness gauges for first-class cars are characterized by low cost, a limited number of functions and complex operation: you must learn how to use them.
The second class has wide capabilities, low speed, but their measurement accuracy is higher than that of the first class models.
Third-class thickness gauges combine quality and price. Devices are more expensive than the models of the first two categories, but surpass them in reliability, accuracy and functionality. Among the disadvantages is the need for regular calibration of the thickness gauge and low resistance to negative temperatures.
Professional appliances belong to the fourth class. Such thickness gauges are self-calibrating, surpassing other models in terms of characteristics, functions, reliability, accuracy and ease of operation.
Application breakdown
Thickness gauges are used in various fields:
- Shipbuilding and automotive industry.
- Construction.
- Insurance activity.
- Expert work.
High measurement accuracy is required in many fields of activity, in particular, in car services. When assessing the scope of work, professionals require instruments that determine the paint coat up to micron fractions. For private use, less accurate thickness gauges are suitable.
Types of thickness gauges according to the principle of operation
Magnetic thickness gauges are the simplest in terms of design and principle of operation. A magnet built into the housing determines the degree of proximity of the metal: the closer it is, the thinner the paint layer. Measurements are shown on the display.
The functioning of electromagnetic devices is based on electromagnetic induction. The sensor of such models of thickness gauges perceives the car body as a closed circuit. The thickness of the coating layer is determined by measuring the density of the magnetic field.
Measurements in hard-to-reach areas of the car are carried out by ultrasonic devices. A pulse is applied to the surface of the body, the magnitude of which is displayed.
Vortex-thickness gauges are used in the evaluation of non-ferrous metals. The paint layer on the surface of the body is measured by passing current through the coil wire and its subsequent effect on the magnetic field.
Universal thickness gauges of the combined type and electromagnetic thickness gauges are the most popular types of devices. On sale are ultrasonic models with an accuracy of 0.1 mm; their functionality does not allow to distinguish unpainted areas from overflow of paint. Industrial devices are focused not only on measuring the thickness of the paintwork and have a high cost.
How to choose a thickness gauge
Manufacturers offer a wide range of devices that vary in cost, functionality, accuracy of measurements. How to choose a thickness gauge and not make a mistake?
What to look for
The fundamental criterion for choosing a thickness gauge is the purpose of its further use. For private use, it is worthwhile to focus on budget devices with the optimal range, duration and working conditions, including technical characteristics.
On professional models, you should not save. When choosing a thickness gauge, the number of functions and operating modes, the amount of error, and the sensitivity of the tester are taken into account.
It is advisable to determine the set of necessary functions. Advanced models of thickness gauges are equipped with sensors for determining the degree of corrosion and measuring fiberglass and rubber. Similar functions are required in shipbuilding and construction, but are not needed in the automotive sector.
Specific functions such as the ability to work underwater will not be needed when working with vehicles. In this case, the backlight will not be superfluous: measurements are not always carried out with a sufficient level of lighting.
Automatic shutdown during prolonged inactivity is a useful feature, especially if the device is a volatile type. No less important when choosing is the accuracy and accuracy of the readings of the thickness gauge of car paintwork. A wide range of measurements, duration of work, resistance to temperatures and climatic conditions are also important.
For operation in the cold season, a magnetic thickness gauge is suitable - it does not depend on temperature, humidity and power supply. For work in the room electronic analogues are more adapted.
The duration of the thickness gauge and the battery capacity are no less important. The language selection function is not critical, but desirable: despite the digital display of readings, the menu should be Russian-language and facilitate the work.
The case material of the thickness gauge, in contrast to its color and sound alert, is important. Most models are made of impact-resistant plastic, but a protective case can be supplied.
Rating of car paint thickness gauges
First place in the ranking is the compact Etari ET-333. The devices of this manufacturer have gained popularity due to their small size and the ability to take measurements anywhere in the body. In the modern Etari line of thickness gauges, the ET-333 model is the most sought after in the electromagnetic series due to the preserved layout of the ET-110 predecessor and improved performance. The accuracy of the readings is 1 micron, the error under normal conditions is not more than 3%, the measurement speed has increased.
Separately, it is worth mentioning the measurement conditions. By default, advertising indicates the temperature within the room and the values for the minimum measurement limit. The measurement error of combined or electromagnetic thickness gauges in the cold and with a large metal thickness increases significantly. To the credit of the manufacturer of Etari thickness gauges, the instructions for the instruments are quite clear: the measurement accuracy decreases by no more than 0.1 / o C at a temperature below 18 degrees. The scatter of measurements for coating 140 microns is 131-148 microns: this range is sufficient, especially if the body did not take care centimeter by centimeter when painting.
The ET-333 model is easy to operate, but requires initial calibration: the thickness gauge is equipped with a steel washer and a 102-micron layer of film for adjustment.
The advantages of the device:
- Compact size and ease of reading data from the display.
- Acceptable accuracy.
- Possibility of measurements on curved surfaces.
Disadvantages:
- Only point measurement is available.
- Lack of measurement memory.
Second place: CEM DT-156
The indisputable advantage of the combined sensor, which took second place in the rating of car paint thickness gauges, was compactness: the convenience of working with bends with a small radius, practically not subject to straightening, is indisputable. The device operates in two modes: continuous and spot measurement. In the first case, not only the current thickness value is displayed, but also the average value during the measurement time and the minimum / maximum. The results are stored in one of 320 memory cells sorted into four groups.
The most accurate indicators of the thickness gauge were recorded during steel measurements: 3% in increments of 1 micron and a radius of curvature of the surface of 1.5 mm. Accuracy in aluminum is similar, but the pitch varies up to one and a half microns, and the radius of curvature is up to 3 mm; the vortex inductor surrounding the central electromagnetic sensor can be called responsible for this.
Unlike most models of thickness gauges, CEM is equipped with a standard set of five, and not one, calibration plates of different thicknesses. The device is synchronized with a computer via USB for data transfer and their subsequent processing by the standard software supplied with the device.
Users may not like the location of the sensor in the lower part of the device, which is why you have to keep the thickness gauge in the direction “away from you” when working with vertical surfaces of the body, while the display is turned upside down. Carrying out several measurements and their subsequent viewing is very inconvenient, so it is not known what the manufacturer hoped for.
Benefits:
- High accuracy.
- Automatic material detection.
- Data collection with continuous measurement.
Disadvantages:
- Ergonomics inconsistency.
- The inconvenience of use.
Third place: UNI-T UT342
UNI-T was included in the rating of paint coat thickness gauges due to the ability to work on ferrous metals and non-ferrous alloys with high accuracy: the declared error does not exceed 3% in the range from 55 microns to 1 mm and standard 3 microns in the range from 0 to 55 microns. Two operating modes are available: spot and continuous measurements, and in the second case, the device automatically calculates the minimum and maximum thickness values.
Up to 2000 measurement results can be stored in the internal memory, which is enough to examine the entire car.
Cold is the enemy of all thickness gauges of this class, including UT342, therefore it is better to work with it indoors. Compliance with the temperature regime has a positive effect on the battery life: the Krona of low power and small capacity is built into the device. In the mode of spot measurements, the battery lasts only 20 hours, with continuous measurements - even less. A very average indicator for a car paint thickness gauge, the price of which is almost 10 thousand rubles.
He has one advantage in comparison with similar device models - high accuracy and the ability to work with metals of any type. The drawback, however, is also one - minimal autonomy.
ET-444: fourth on the list
A compact device of the combined type, made in the same case as the ET-555 thickness gauge, and is almost identical in application to the previous models - the sensor abuts against the surface, and then the measurement starts. The operation of the device automatically starts in electromagnetic mode, in the absence of steel goes into eddy current.
The introduction of the eddy current sensor increased the price of the car paint thickness gauge by only 1,400 rubles and made it more interesting than its predecessors: the functionality increased, but the accuracy remained the same.
Benefits:
- Compact dimensions.
- Ability to work anywhere in the body and with any metal.
Disadvantages:
- Lack of continuous metering mode.
Fifth place: ET-11P
The manufacturer approached the creation of this model with a good sense and arrangement: three washers for calibration are included. The first is designed to check the thickness gauge for magnetic metals, the second for non-ferrous alloys, the third is an imitation of a paint coating of a reference thickness. A completely identical model is sold under the label CHY-115; both brands are supervised by one manufacturer - EuroTrade. Therefore, the question of which company to choose a thickness gauge in this case is meaningless.
ET-11P is completed with reference data on the average thickness of the paintwork of cars of popular makes and models - not only useful information, but also the ability to check the device for compliance with the measurements made by it with real values. The accuracy declared by the manufacturer - 3% - in practice, when setting on a standard plate, it is confirmed: the thickness gauge readings vary between 104-100 microns under ideal conditions. In the cold, the accuracy of the readings decreases slightly, which is quite logical.
The sound indication of the continuous mode turned out to be very convenient in practice: you can observe the readings, or you can change the settings and ignore the display - the device will give an audible signal when the measured thickness exceeds the limits.
In theory, a pistol-shaped case should be convenient, but in practice everything is different: accurate measurements can be achieved only if the device abuts against the surface with all the protrusions of the end part. In some parts of the body - next to the headlights, rounded elements - the thickness gauge will be useless. However, a similar problem is typical for all devices of the trigger type: a large measuring platform affects.
Benefits:
- Ability to save 255 measurements in memory.
- Convenient and large display.
Disadvantages:
- Not always a comfortable shape;
- Focused on measurements on the plane.
Sixth: Elcometer 456
Model of a universal thickness gauge working with all types of metals. The standard error is 3% when working with coatings with a thickness of 0 to 31 mm. A solution with built-in or remote sensors connected via a connector is very successful in practice. The monoblock performed well when measuring on flat and open surfaces, the body with removable sensors - when measuring hard-to-reach areas with complex terrain.
Included with both versions of the Elcometer 456 comes one of three sensors - eddy current, magnetic, or universal. Type F sensors are used with magnetic metals. Surfaces from non-ferrous and other metals are measured by type N sensors. Combined FNF sensors are used for non-ferrous and ferrous metals.
Seventh place: "Constant"
Multifunctional thickness gauge "Constant K5" is a device that operates in several modes using different methods: parametric, induction and eddy current.
The manufacturer offers two modifications of the thickness gauges of this series - for standard conditions and underwater for measurements at a depth of 60 meters or more. Various measurement methods allow working with coatings of various metals - ferrous, non-ferrous, alloys, dielectric, with ferromagnetic properties and others. New data processing algorithms transform the obtained measurements with high accuracy.
In the rating of thickness gauges for paint and varnish coatings of cars, "Constant" turned out to be due to its underwater modification - very interesting, it is worth noting; It belongs to the professional category and is applied in narrow areas. Uses magneto-induction method; can make measurements on plastic, enamel, paint and varnish and other types of surfaces of non-ferromagnetic type.
The remote control is designed to calibrate the thickness gauge of the underwater version. "Constant K5" can operate in fresh and sea water without interruptions in readings and reduce the accuracy of measurements.
Which thickness gauge is better to choose?
Interest in thickness gauges and their assortment actually turns into a very meager choice: if you do not take into account cheap models and expensive professional equipment of high accuracy, then there are only a few brands. So, which company thickness gauge to choose? The list of worthy brands is regrettably small, and three of them are completely of the same factory: Etari, CHY and EuroTrade, which in fact are not different from each other and are almost identical. An unexpected exception is the Megeon thickness gauges - reliable and accurate instruments.
The devices of the trigger type upon closer inspection are not always successful copies of the Etari ET-10 or ET-11 and differ in body color and cost. Therefore, when choosing a thickness gauge, you should rely on the following recommendations:
- Need a compact instrument with acceptable accuracy, able to go over the body of a car, chosen for yourself or friends, acquaintances? It is worth paying attention to combined or electromagnetic thickness gauges: they have sufficient accuracy, small dimensions, affordable price and are easy to operate.
- For professional use, handheld combined instruments of the CEM DT-156 type would be an ideal option: it is unlikely to have to inspect cars under snowfall. The popularity of trigger devices is rapidly declining: the inconvenient shape of the case has done its job, and modern multifunctional and compact models have finally replaced them from the market.
And, of course, armed with a reliable thickness gauge, it remains to be right with the car.