Accidents accompanied by body repairs are a headache for buyers who buy cars on the secondary market. A professional car paint thickness gauge will help you identify signs of repainting, puttying and replacing parts.
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 machine defects. The measurement accuracy of the device depends on its type and principle of operation.
Classification
First-class auto thickness gauges are low cost, limited in function and difficult to operate: you need to 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. The devices are more expensive than the models of the first two categories, but surpass them in reliability, accuracy and functionality. Fromdisadvantages - the need for regular calibration of the thickness gauge and low resistance to negative temperatures.
Professional appliances belong to the fourth class. These thickness gauges are self-calibrating and outperform other models in performance, function, reliability, accuracy and ease of use.
Separation by scope
Thickness gauges are used in different areas:
- Shipbuilding and automotive industry.
- Construction.
- Insurance activities.
- Expert work.
High measurement accuracy is required in many areas of activity, in particular - in car services. When assessing the scope of work, professionals require instruments that determine the layer of paintwork down to micron fractions. For private use, less accurate thickness gauges will do.
Types of thickness gauges according to the principle of operation
Magnetic thickness gauges are the simplest in terms of design and operation. The magnet built into the case 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 paint layer is determined by measuring the magnetic field density.
Measurements in hard-to-reach places of the car are carried out by ultrasonic devices. An impulse is applied to the surface of the body,the value of which is displayed.
Vortex thickness gauges are used in the evaluation of non-ferrous metals. The layer of paint on the surface of the body is measured by passing current through the coil wire and its subsequent effect on the magnetic field.
Universal combined type thickness gauges and electromagnetic thickness gauges are the most popular types of gauges. On sale, ultrasonic models with an accuracy of 0.1 mm are common; their functionality does not allow distinguishing unpainted areas from paint overflow. Industrial instruments are not only focused on measuring the thickness of the paint coating and are expensive.
How to choose a thickness gauge
Manufacturers offer a wide range of devices that differ in cost, functionality, measurement accuracy. How to choose a thickness gauge and not make a mistake?
What to look out for
The main criterion for choosing a thickness gauge is the purpose of its further use. For private use, it is worth focusing on budget devices with the optimal range, duration and operating conditions, including technical characteristics.
It's not worth saving on professional models. When choosing a thickness gauge, the number of functions and modes of operation, the magnitude of the error, and the sensitivity of the tester are taken into account.
It is desirable to decide on 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. Similarfeatures are required in shipbuilding and construction, but are not needed in the automotive sector.
Special features like the ability to work under water will not be needed when working with vehicles. At the same time, the backlight will not be superfluous: measurements are not always carried out with a sufficient level of illumination.
Automatic shutdown after prolonged inactivity is a useful feature, especially if the device is a volatile type. Equally important when choosing is the accuracy and error of readings of the thickness gauge of car paintwork. Also important is a wide measurement range, duration of operation, resistance to temperatures and climatic conditions.
For operation in the cold season, a magnetic thickness gauge is suitable - it does not depend on temperature, humidity and power supply. Electronic analogues are more suitable for indoor work.
Thickness gauge life and battery capacity are just as important. The language selection function is not critical, but desirable: despite the digital output of readings, the menu should be in Russian and facilitate work.
The material of the body of the thickness gauge, in contrast to its color and sound notification, is important. Most models are made of high-impact plastic, but a protective case may be included.
Rating of car paint thickness gauges
The first place in the ranking is occupied by the compact Etari ET-333. The popularity of the devices of this manufacturer was due to their small size andthe ability to take measurements at any point of the body. In the modern line of Etari thickness gauges, the ET-333 model is the most demanded of the electromagnetic series due to the retained layout of the predecessor ET-110 and improved performance. The accuracy of the instrument readings is 1 micron, the error under normal conditions is no more than 3%, the measurement speed has increased.
Separately, it is worth mentioning the conditions of measurements. As a standard, advertisements indicate temperatures within room temperature and values for the minimum measurement limit. The measurement error of combined or electromagnetic thickness gauges in the cold and with a large thickness of the metal increases significantly. To the credit of the manufacturer of thickness gauges Etari, the instructions for the instruments are quite clear: the measurement accuracy decreases by no more than 0.1/oC at temperatures below 18 degrees. The measurement spread for a 140 micron coating is 131-148 microns: this range is sufficient, especially if the body was not nurtured centimeter by centimeter during painting.
The ET-333 is easy to use but requires initial calibration: the thickness gauge comes with a steel washer and a 102 micron film for adjustment.
Device Benefits:
- Compact size and easy to read display.
- Acceptable accuracy.
- Possibility of measuring on curved surfaces.
Flaws:
- Only spot measurement available.
- No measurement memory.
Second Place: CEM DT-156
The indisputable advantage of the combined sensor, which took second place in the rating of thickness gauges for car paintwork, was its compactness: the convenience of working along bends with a small radius, which is practically not subject to straightening, is indisputable. The device operates in two modes: continuous and point measurement. In the first case, not only the current thickness value is displayed, but also the average value over the measurement time and the minimum / maximum. The results are stored in one of 320 memory locations sorted into four groups.
The thickness gauge is most accurate when measuring steel: 3% in 1 micron increments and a surface curvature radius of 1.5 mm. The accuracy for aluminum is similar, but the pitch varies up to one and a half microns, and the radius of curvature - 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 regular set of five, 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 at the bottom of the gauge, which means that you have to hold the thickness gauge away from you when working on vertical surfaces of the body, while the display turns upside down. Taking several measurements and then reviewing them is very inconvenient, so it is not known what the manufacturer was hoping for.
Benefits:
- High accuracy.
- Automatic material detection.
- Data acquisition in continuous measurement.
Flaws:
- Illogical ergonomics.
- Inconvenient to use.
Third place: UNI-T UT342
UNI-T got into the rating of car paint 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 the standard 3 microns in the range from 0 up to 55 microns. Two operating modes are available: spot and continuous measurements, in the second case, the device automatically calculates the minimum and maximum thickness values.
Up to 2000 measurements can be stored in the built-in memory, which is enough to inspect the entire vehicle.
Cold is the enemy of all thickness gauges of this class, including UT342, so it is better to work with it indoors. Compliance with the temperature regime has a positive effect on the battery life: the device has a built-in "Krona" of low power and small capacity. In the spot measurement mode, 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.
It has one advantage in comparison with similar models of devices - high accuracy and the ability to work with metals of any type. The disadvantage, however, is also one - the minimumautonomy.
ET-444: Fourth on the list
Compact combined type device, made in the same housing as the thickness gauge ET-555, and almost identical in application to previous models - the sensor rests on the surface, after which the measurement starts. The operation of the device automatically starts in electromagnetic mode, in the absence of steel it switches to eddy current.
The introduction of an eddy current sensor increased the price of a car paint thickness gauge by only 1400 rubles and made it more interesting than its predecessors: the functionality has increased, but the accuracy has remained the same.
Benefits:
- Compact dimensions.
- Ability to work anywhere in the body and with any metal.
Flaws:
No continuous metering mode
Fifth place: ET-11P
The manufacturer approached the creation of this model with sense and arrangement: three washers for calibration are included in the kit. The first is designed to check the thickness gauge for magnetic metals, the second - for non-ferrous alloys, the third - imitation of the paintwork of the reference thickness. An absolutely identical model is sold under the marking CHY-115; both brands are supervised by one manufacturer - EuroTrade. Therefore, the question of which company to choose a thickness gauge is meaningless in this case.
ET-11P is equipped with reference data on the average thickness of the paintwork of popular makes and models of cars - not only useful information, but also an opportunitychecking the device for compliance with the measurements made by it with real values. The accuracy declared by the manufacturer - 3% - is confirmed in practice when adjusting to a standard plate: the thickness gauge readings vary within 104-100 microns under ideal conditions. In the cold, the accuracy of the readings is somewhat reduced, 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 beep when the measured thickness goes beyond the limits.
In theory, the pistol-type body should be comfortable, but in practice everything is different: accurate measurements can be achieved only if the device rests against the surface with all the protrusions of the end part. In some areas of the body - next to the headlights, rounded elements - the thickness gauge will be useless. However, a similar problem is typical for all trigger-type devices: a large measuring platform affects.
Benefits:
- Ability to store 255 measurements in memory.
- Convenient and large display.
Flaws:
- Not always a convenient form;
- Oriented to plane measurements.
Sixth: Elcometer 456
Model of the universal thickness gauge working with all types of metals. The error is standard - 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. Monoblock performed well inmeasurements on flat and open surfaces, a body with removable sensors - when measuring hard-to-reach areas with difficult terrain.
Both versions of Elcometer 456 are supplied with one of three sensors - eddy current, magnetic or universal. Type F sensors are used when working with magnetic metals. Non-ferrous and non-ferrous metal surfaces are measured with N-type probes. FNF combined probes are used for non-ferrous and ferrous metals.
Seventh place: "Constant"
Multifunctional thickness gauge "Constant K5" - 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 you to work with coatings made of various metals - ferrous, non-ferrous, alloys, dielectric, with ferromagnetic properties, and others. New data processing algorithms convert the received measurements with high accuracy.
In the rating of thickness gauges for car paint coatings "Constant" turned out to be due to its underwater modification - very interesting, it is worth noting; it belongs to the professional category and is used in narrow areas. Uses the magnetic induction method; can take measurements on plastic, enamel, paintwork and other types of non-ferromagnetic surfacestype.
The remote control panel is designed to calibrate the underwater version of the thickness gauge. "Constant K5" can operate in fresh and sea water without failures in readings and loss of measurement accuracy.
Which thickness gauge is better to choose?
Interest in thickness gauges and their range actually turns into a very meager choice: if you do not take into account cheap models and expensive professional high-precision equipment, then there are only a few brands left. So, which brand thickness gauge to choose? The list of worthy brands is regrettably small, and three of them are from the same factory: Etari, CHY and EuroTrade, which in fact do not differ from each other and are almost identical. An unexpected exception is the Megeon thickness gauges - reliable and accurate instruments.
On closer inspection, trigger-type devices turn out to be not always successful copies of 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:
- Do you need a compact device with acceptable accuracy, capable of running through the body of a car, chosen for yourself or friends and 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, manual combined instruments like CEM DT-156 are ideal: it is unlikely that you will have to inspect cars under snow. The popularity of trigger devicesis rapidly falling: the inconvenient shape of the case has done its job, and modern multifunctional and compact models have finally forced them out of the market.
And, of course, armed with a reliable thickness gauge, you can't go wrong with the car.
