Technology
The engineering behind an accurate reading
Since 2007 CARSYS has designed its own sensors, wound its own coils and written its own algorithms. Accuracy, speed and reliability are not magic — they are the sum of engineering decisions.
11 technologiessince 2007own design and production
All technologies
All of them, briefly
Eleven decisions that add up to a reading
Pick a technology to jump straight to its breakdown. Below they follow the same order.
Sensor & precision
Differential magnetic-induction sensor
Two measuring coils instead of one: the gauge compares their signals and subtracts interference before it ever shows you a number. Reading after reading on the same spot gives the same result — even with a lift running nearby or the temperature drifting in the shop.
- Higher repeatability: one spot, one number
- Less affected by pickup and vibration
- Stable in cold and heat, from −25 °C
A single coil picks up interference and drifts with temperature — at the paint/filler boundary the reading wanders and the check has to be repeated.
Sensor & precision
Combined Fe / NFe sensor
One gauge works on both steel and aluminium: it detects the metal under the coating and switches the measuring method itself. No picking a mode, no remembering what a fender or hood is made of.
- Steel and non-ferrous metals with no manual switching
- Automatic substrate detection in a fraction of a second
- One gauge for the whole car, aluminium panels included
A single-range gauge simply lies or stays silent on aluminium — half of modern bodies cannot be checked with it.
Sensor & precision
Floating (spring-loaded) sensor
The tip sits on a spring-loaded travel and evens out the contact force itself. You just press the gauge to the surface — it seats with the same force every time, even on a door edge or a rounded pillar.
- Steady contact force — less scatter in the readings
- Confident measurement on curves, edges and rounded parts
- Less dependence on how firm the operator’s hand is
A rigidly mounted sensor measures “however you press it”: on a curved surface it seats poorly, the reading drops — and a defect can be missed.
What it detects
Factory zinc detection
Factory galvanising can’t be recreated by a respray — a panel either has it or it doesn’t. The gauge lets you compare neighbouring panels: every door reads zinc but one, or the left wing is galvanised while the right isn’t — that panel was almost certainly replaced, even when the paint thickness matches everywhere.
- Spot a swap by its neighbours: one panel with no zinc among galvanised ones
- Matching paint thickness still doesn’t prove an original panel
- On the AVTOPODBOR line you set the sensitivity threshold yourself
A gauge that only sees thickness shows the same number on an original panel and a replaced one. It misses the missing factory zinc — and the swap along with it.
Every CARSYS gauge carries the zinc detector. The sensitivity threshold is adjustable on the AVTOPODBOR line; on the DPM-816 line it is fixed.
What it detects
Magnetic filler detection
Iron-bearing filler is nearly invisible to ordinary gauges — it responds to the magnet much like metal. CARSYS recognises this kind of repair and warns you, and on the AVTOPODBOR line the sensitivity can be tuned to the task.
- Finds hidden bodywork under a thin coat of paint
- Detects ferromagnetic filler, not just a thick paint layer
- On the AVTOPODBOR line — sensitivity tuned to the type of repair
Without this, filler over metal is easily taken for original steel — serious repair goes unnoticed at purchase.
Every CARSYS gauge carries the filler detector. The sensitivity threshold is adjustable on the AVTOPODBOR line; on the DPM-816 line it is fixed.
Sensitivity adjustment
Tuned to the specific body
Detecting zinc and magnetic filler is not a fixed factory yes/no. Sensitivity is tuned to the panel: catch a thin layer, but don’t mistake ordinary metal background for one. Drag the threshold and watch the verdict change.
Optimal: the layer is detected and the metal background is rejected — an honest result.
Principle illustration. Levels are relative, not real sensor readings.
What the gauge reveals
Coating layers laid bare
Run the probe across the section: the gauge separates factory paint from a respray and filler. This is exactly what you see on a real body — just without the cut.
Gauge reading
120µm
Never repainted
Factory finish
Factory finish
120 µm
Repainted
200 µm
Body filler repair
620 µm
Drag across the section or use arrow keys
Layers are drawn to scale by thickness
How it measures
Smart automatic measurement
No buttons, no end-stops: the gauge senses the touch of the surface and takes the reading itself. Just press it on — the result is already on screen. Works even with a shaking hand in the cold.
- Measures on contact, no button press
- Protection against misfires with shaky hands
- No mechanical button — nothing to wear out or stick
Buttons and end-stops fire every other time and are the first to fail — the gauge starts “skipping” readings within a season.
How it measures
Turbo mode
The gauge stays in Auto — it still recognises the metal and the detectors still run — but it fires sooner. That comes from slightly relaxed auto-trigger criteria: the gauge accepts a reading even if your hand shakes a little.
- A faster walk-around: every spot returns its result sooner
- Fires even with a slight tremor in the hand
- Toggled by holding one button — everything else works as in Auto
Without turbo every spot takes more accumulations — over a long walk-around those fractions of a second add up to minutes.
Turbo mode comes with the AVTOPODBOR line — AVTOPODBOR and AVTOPODBOR-M. The speed comes from relaxed trigger criteria and fewer result accumulations, so it is switched on once the probe is already seated squarely and confidently. The DPM-816 line has no turbo mode.
How it measures
High-speed continuous measurement
The gauge measures in a stream, several times a second, as you run it along the surface. Invaluable where you cannot hold the sensor strictly perpendicular — on pipes, edges and complex curved parts.
- A continuous stream of readings — a fast sweep of the whole part
- Works on pipes and surfaces you cannot stand square to
- Quickly finds the worst spot without dozens of separate presses
A single-reading gauge makes you “peck” at the surface dozens of times — on a complex part that is slow, and the problem area is easy to miss.
Comfort & durability
Backlit FSTN LCD display
Cars are inspected outdoors, and usually by day. A colour screen washes out in bright sun: you end up catching the reading in the shade of your own hand. An FSTN matrix works the other way round, on reflected light — the brighter the sun, the crisper the figures. The backlight is for where there is no light: a workshop bay, an underground car park, a courtyard in the evening.
- Crisp figures in direct sun — the screen does not wash out
- Backlight on a button: the bay, the car park, an evening check
- Very low draw — the gauge runs on ordinary AAA cells
A screen that emits its own light loses outdoors: on a clear day the reading drowns in glare, and the inspection turns into a hunt for shade.
Why LCD rather than TFT or OLED
A colour screen looks more modern. For a gauge you carry out to a car, other things matter.
| What matters during an inspection | Backlit FSTN LCD | TFT/IPS | OLED |
|---|---|---|---|
| In direct sun | The brighter the light, the higher the contrast: the matrix works on reflected light | Washes out — the reading is read in the shade of your hand | Washes out: not bright enough against the sun |
| Digit size | The whole screen is given to the figures — legible at arm’s length | Rarely fitted in a housing this size | Modules are small, so the digits are noticeably smaller |
| Power draw | Very low: without the backlight the gauge runs a long time on one cell | Needs a rechargeable pack and regular charging | Higher than LCD, especially on a light image |
| Frost | Works; in the cold the image refreshes more slowly | Response drops, the backlight dims | Handles cold better — its one advantage |
| Burn-in | No burn-in: the screen layout is the same years later | No burn-in | A static layout burns in over time |
In deep frost, below −15 °C, OLED really does behave better — that is the one row it wins. The operating range of CARSYS gauges covers a winter inspection in full: down to −30 °C in the AVTOPODBOR line and −25 °C in the DPM-816 line.
Comfort & durability
Colour assistant
The gauge shows not just a number but a colour band: green for factory coating, amber for thickening, red for a likely repair. You read the verdict with peripheral vision, without parsing figures.
- Instant “ok / caution / repair” read by colour
- A fast body sweep without reading every number
- Clear even to those who don’t remember paint-thickness norms
With a bare number, every reading must be held in your head and compared to the norm — the sweep is slower, and fatigue leads to mistakes.
Comfort & durability
Polymer housing coating
The housing is finished with a special polymer: pleasant in the hand, non-slip, fingerprint-free, and it shrugs off scratches from keys, tools and grit in a work-jacket pocket.
- Non-slip grip that doesn’t collect fingerprints
- Resistant to scratches and scuffs
- Looks and feels new for years
Glossy plastic scratches and smudges from day one — the gauge quickly loses its look and sits worse in the hand.
In the field
Not in a lab — on the body
By day and in the dark, on a flat panel and on an edge: the green indicator confirms a valid reading, and the number is right there on screen.
In brief
CARSYS vs an ordinary gauge
What of the above a CARSYS gauge has, and what a typical budget gauge usually does not.
| Technology | CARSYS | Ordinary gauge |
|---|---|---|
| Combined Fe / NFe sensor | yes | no |
| Differential sensor | yes | no |
| Floating sensor | yes | no |
| Zinc detection | yes | no |
| Magnetic filler detection | yes | no |
| Adjustable sensitivity* | yes | no |
| Auto-measure on contact | yes | no |
| Turbo mode* | yes | no |
| High-speed continuous measurement | yes | no |
| Colour assistant | yes | no |
| Polymer housing coating | yes | no |
“Ordinary gauge” means a typical budget single-range device. Some features (a backlight, say) do appear on them, but they usually lack the set of technologies above. * Zinc and filler detectors are fitted to every CARSYS gauge; an adjustable sensitivity threshold and turbo mode come with the AVTOPODBOR line, while on the DPM-816 line the threshold is fixed and there is no turbo mode.
Frequently asked
Frequently asked
What measuring range does a gauge need for a body check?
For a professional inspection a range up to 1000 micrometres is plenty: at 500 and above it is already clear that filler was used. The range that matters most for an automotive gauge is 50 to 500 micrometres.
How does magnetic induction differ from eddy current, and why have both?
Magnetic induction measures ferrous metals more accurately and, unlike eddy current, holds its accuracy when surface roughness changes. Eddy current in turn provides the accuracy needed on non-ferrous metals. Together they cover the whole body — which is why an automotive gauge carries both.
Does temperature affect gauge accuracy?
It does affect the readings. On good modern gauges this temperature drift is minimal and is compensated in software.
What is reading adjustment?
It is when a gauge compares a new measurement with the previous one and, if the numbers are close, shows the old value on screen instead of the new one. Some devices go further: on the third measurement they output the average of the two before it. Every device draws the line at “close” differently — anywhere from one per cent plus 1–5 micrometres to one per cent plus 10. In practice it looks like this: you measure a 100-micrometre coating; the device reads 95 and shows 95; the second time it reads 100, yet the display still says 95; the third time 110, and it shows 110; the fourth time 105, and it shows 110 again. CARSYS gauges do not adjust readings, so the number on screen can always be trusted. That matters when you are looking for the edge of a repair and small local touch-ups.
Why does the gauge have a monochrome screen rather than a colour one?
Because bodywork is inspected outdoors, and in bright sun a colour screen washes out — you end up shading the reading with your hand and looking for somewhere darker to stand. A monochrome FSTN matrix emits no light of its own; it works on reflected light, so the brighter the day, the crisper the figures. It also draws very little power, which is why the gauge runs a long time on ordinary AAA cells instead of needing a charge before every trip. The backlight comes on at the press of a button for a workshop bay, an underground car park or an evening check, and switches itself off after a minute of inactivity.
Why does a cheap gauge lie if the principle is the same?
The principle is not the same. Cheap devices usually carry a probe with one small coil and a plastic tip: it measures by eddy current, and on ferrous metals that method gives far too large an error. Calibrate such a device on a steel plate with reference films and the results will look plausible. The catch comes with varying roughness: even on one grade of steel the discrepancy between a smooth and a matte surface reaches 50–100 micrometres. On top of that these devices hold calibration poorly — they have to be set up at every use and at every change of metal type.
Knowledge base
Read next
Material that carries the topic on: how to check a body, what the gauge does and which one to choose.
Pick a gauge with the technology you need
From the compact AVTOPODBOR to the professional DPM-816 PRO — every core CARSYS technology is already inside.