Leeb Coating Thickness Gauges
A coating thickness gauge is a handheld non-destructive instrument that measures the dry film thickness of paint, powder coat, zinc, anodising or other coatings on a metal part, without damaging the coating. Leeb gauges use magnetic induction (Fe) for coatings on steel and iron, and eddy current (NFe) for coatings on aluminium, copper and other non-magnetic metals.
Ecotao supplies the current Leeb range, from pocket one-button gauges to printer-equipped inspection kits, across South Africa and neighbouring countries.
Figures from Leeb's published specifications. Resolution and accuracy vary by model; see the comparison table.
How a coating thickness gauge works: Fe vs NFe
The gauge's probe sits on the coated surface. The coating acts as a spacer between the probe tip and the metal underneath, and the gauge converts the change in a magnetic or electrical signal into a thickness reading. Which method works depends entirely on the substrate, not the coating.
FeMagnetic induction
The probe creates a magnetic field that closes through the steel substrate. The thicker the non-magnetic coating, the weaker the flux reaching the steel, and the gauge reads that drop as thickness.
Measures: paint, powder coat, epoxy, rubber, zinc (galvanising), chrome, copper and tin plating on steel, iron and magnetic alloys.
NFeEddy current
A high-frequency coil induces eddy currents in the conductive metal. As the non-conductive coating gets thicker, the coupling between coil and metal weakens, and the gauge reads that change as thickness.
Measures: paint, lacquer, powder coat, plastic and anodised (oxide) layers on aluminium, copper, brass, zinc and non-magnetic stainless steel.
Dual Fe/NFe gauges handle both substrates. On most Leeb dual models you fit the Fe or NFe probe for the job; the compact Leeb252 has its probe built into the body. If your workshop coats both steel and aluminium, a dual gauge avoids buying two instruments.
How to choose a Leeb coating thickness gauge
Work through these five questions in order. The first two decide which models are possible; the last three decide which is most practical.
- What is the substrate? Steel or iron needs Fe. Aluminium, copper or other non-magnetic metals need NFe. Both, or unsure from job to job, choose a dual Fe/NFe gauge.
- How thick is the coating? Paint, powder coat and galvanising almost always fall inside 0–1250 µm, which every model covers. Thick intumescent fire protection, heavy rubber linings or multi-coat systems above 1.25 mm need the Leeb253 (0–6000 µm, steel only).
- Do you need to prove the readings? For QA records, client sign-off or inspection reports, choose memory with statistics plus PC software (UEE920, UEE922) or on-site printing (UEE923 built-in; Leeb242 and Leeb262 wireless micro-printer).
- Where will it be used? Fabrication yards and site work favour a metal housing (Leeb230 series, UEE922). Changeable probes (UEE series, Leeb242, Leeb262) let you add a second probe later instead of buying a second gauge.
- How small or curved are the parts? Most models need a 7 mm flat spot and handle convex curves down to 1.5 mm radius. The Leeb252 and Leeb253 need a 10 mm spot and 20 mm concave radius, so small fittings and tight internal corners suit the other models better.
| If you need… | Start with |
|---|---|
| Quick paint or powder checks on steel and aluminium | Leeb252 (one-button, built-in probe) |
| Rugged Fe-only gauge for a steel fabrication shop | Leeb230 |
| Anodising or powder coat on aluminium only | Leeb211 or Leeb231 |
| Dual Fe/NFe with PC reporting | UEE920 (plastic) or UEE922 (metal) |
| Printed results on site | UEE923, Leeb242 or Leeb262 |
| Intumescent fireproof coatings over 1.25 mm | Leeb253 |
Leeb coating thickness gauge models
All models below are current in Leeb's catalogue. Stock and lead times vary, so please confirm availability with Ecotao before ordering.
Leeb252
The simplest dual-mode gauge in the range. The probe is built into the body and measurement is one button, which suits painters, powder coaters and quick incoming-goods checks.
- Range0–1250 µm
- Resolution1 µm
- Accuracy±[(1–3%)H+1] µm
- ProbeBuilt-in
- Power / weightAAA · 120 g
Leeb253
Leeb designed the 253 specifically for fireproof coatings. Its 0–6000 µm range covers intumescent paint and heavy protective systems on structural steel that are beyond the 1250 µm limit of every other model.
- Range0–6000 µm
- Resolution1 µm
- Accuracy±[(1–3%)H+1] µm
- SubstrateSteel / iron only
- Power / weightAAA · 120 g
Leeb230, Leeb231 & Leeb232
A metal-cased series for workshop and site use, with 0.1 µm resolution. Pick the 230 for steel, the 231 for aluminium and other non-magnetic metals, or the 232 for both. Leeb offers optional probes for the 232.
- Range0–1250 µm
- Resolution0.1 µm
- Accuracy±[(1–3%)H+1] µm
- HousingMetal
- PowerAAA alkaline
Leeb211
A compact, economical eddy-current gauge for anodisers, aluminium window and shopfitting manufacturers and powder coaters who only coat non-magnetic metals.
- Range0–1250 µm
- Resolution0.1 µm
- Accuracy±[(1–3%)H+1] µm
- Memory500 readings
- PowerAAA alkaline
UEE920
A reporting-focused gauge. It stores 1560 readings across four material groups, calculates five statistics and transfers data to PC software over USB. The standard kit includes one probe (Fe or NFe); the second can be added later.
- Range0–1250 µm
- Resolution0.1 µm
- Accuracy±(2%H+1) µm
- Memory1560 readings
- Housing / powerPlastic · 2×AA
UEE922
The UEE920's features in a smaller metal housing (130 × 70 × 30 mm) for harder site conditions. Same memory, statistics, PC software and three calibration methods (one-, two- or five-point).
- Range0–1250 µm
- Resolution0.1 µm
- Accuracy±(2%H+1) µm
- Memory1560 readings
- Housing / powerMetal · 2×AA
UEE923
The highest-rated accuracy in the range and a built-in thermal printer (56.5 mm paper), so inspectors can hand over a printed result on site. Leeb rates the Li-ion battery at about 10 hours of continuous use.
- Range0–1250 µm
- Resolution0.1 µm
- Accuracy±(1%H+1) µm
- PrinterBuilt-in thermal
- Power / weightLi-ion · 420 g
Leeb242
A full-featured inspection gauge with changeable Fe or NFe probes, direct and group working modes, automatic zero correction, limit alarms and wireless printing to the supplied micro-printer. Runs on a 6 V rechargeable Ni-MH battery.
- Range0–1250 µm
- Resolution0.1 µm
- Accuracy±[(1–3%)H+1] µm
- Memory500 readings
- DataUSB · wireless print
Leeb262
Changeable Fe or NFe probes with a rechargeable lithium battery, USB PC connection and wireless printing. Limit alarms flag any reading outside your specification, and two calibration methods correct for probe system error.
- Range0–1250 µm
- Resolution0.1 µm
- Accuracy±[(1–3%)H+1] µm
- Memory500 readings
- PowerRechargeable lithium
Leeb coating thickness gauge comparison table
Specifications are taken from Leeb's current product pages. "Ask Ecotao" means Leeb does not publish that figure for the model.
← Scroll to see full table →
| Model | Principle | Range | Resolution | Accuracy | Memory | Housing | Power | Printing | Dimensions |
|---|---|---|---|---|---|---|---|---|---|
| Leeb211 | NFe | 0–1250 µm | 0.1 µm | ±[(1–3%)H+1] µm | 500 | Ask Ecotao | 2×AAA | Ask Ecotao | 115×70×30 mm |
| Leeb230 | Fe | 0–1250 µm | 0.1 µm | ±[(1–3%)H+1] µm | Ask Ecotao | Metal | 2×AAA | Ask Ecotao | 150×55.5×23 mm |
| Leeb231 | NFe | 0–1250 µm | 0.1 µm | ±[(1–3%)H+1] µm | Ask Ecotao | Metal | 2×AAA | Ask Ecotao | 150×55.5×23 mm |
| Leeb232 | Fe or NFe | 0–1250 µm | 0.1 µm | ±[(1–3%)H+1] µm | Ask Ecotao | Metal | 2×AAA | Ask Ecotao | 150×55.5×23 mm |
| Leeb242 | Fe or NFe (changeable) | 0–1250 µm | 0.1 µm | ±[(1–3%)H+1] µm | 500 | Ask Ecotao | 6 V Ni-MH rechargeable | Wireless micro-printer | 230×86×46 mm |
| Leeb252 | Fe or NFe | 0–1250 µm | 1 µm | ±[(1–3%)H+1] µm | Ask Ecotao | Ask Ecotao | 4×AAA | Ask Ecotao | 150×55.5×23 mm, 120 g |
| Leeb253 | Fe | 0–6000 µm | 1 µm | ±[(1–3%)H+1] µm | Ask Ecotao | Ask Ecotao | 4×AAA | Ask Ecotao | 150×55.5×23 mm, 120 g |
| Leeb262 | Fe or NFe (changeable) | 0–1250 µm | 0.1 µm | ±[(1–3%)H+1] µm | 500 | Ask Ecotao | Rechargeable lithium | Wireless micro-printer | 230×86×46 mm |
| UEE920 | Fe & NFe (changeable) | 0–1250 µm | 0.1 µm | ±(2%H+1) µm | 1560 | Plastic | 2×AA | No (PC software) | 163×78×33 mm |
| UEE922 | Fe & NFe (changeable) | 0–1250 µm | 0.1 µm | ±(2%H+1) µm | 1560 | Metal | 2×AA | No (PC software) | 130×70×30 mm |
| UEE923 | Fe & NFe (changeable) | 0–1250 µm | 0.1 µm | ±(1%H+1) µm | 1560 | Ask Ecotao | Li-ion rechargeable | Built-in thermal | 238×90×38 mm, 420 g |
Measurement limits (what size of part can be measured)
| Limit | Leeb252 & Leeb253 | All other current models |
|---|---|---|
| Minimum measuring area | Ø10 mm | Ø7 mm |
| Minimum convex radius | 1.5 mm | 1.5 mm |
| Minimum concave radius | 20 mm | 9 mm |
| Minimum substrate thickness | 0.5 mm | 0.5 mm |
| Operating temperature | 0–40 °C | 0–40 °C (where stated by Leeb) |
Reading the accuracy formula. H is the coating thickness in µm. A gauge rated ±[(1–3%)H + 1] µm reading a 100 µm coat is accurate to roughly ±2 to ±4 µm; at 1000 µm, roughly ±11 to ±31 µm. The UEE920 and UEE922 (±(2%H + 1) µm) give about ±3 µm at 100 µm, and the UEE923 (±(1%H + 1) µm) about ±2 µm. These ratings assume the gauge has been zeroed and calibrated on the actual substrate with the supplied calibration specimens.
Coating thickness gauge applications
Hot-dip galvanising inspection
Zinc is non-magnetic, so a Fe gauge reads it directly on the steel. Inspectors take readings across each reference area and compare the mean against the minimum SANS 121 (ISO 1461) sets for that steel thickness, for example an 85 µm minimum mean on steel thicker than 6 mm. Memory and statistics (UEE920/922, Leeb242, Leeb262) save transcribing readings by hand.
Protective coatings on structural steel
Too little dry film thickness shortens the life of a corrosion-protection system; too much wastes paint and can cause cracking. Painters check wet-to-dry build coat by coat, and inspectors confirm the final DFT against the specification before sign-off. A metal-housed gauge (Leeb230, UEE922) stands up better to site handling.
Intumescent fire protection
Intumescent coatings on steel beams and columns are applied in layers that often exceed 1 mm, and the fire rating depends on reaching the specified thickness. The Leeb253 reads up to 6000 µm, which covers these systems where standard gauges stop at 1250 µm.
Powder coating and anodising on aluminium
Aluminium window, door and shopfitting manufacturers measure powder coat and anodic oxide film with an NFe gauge. Consistent film build matters for durability and for colour and gloss consistency across a batch. The Leeb211 and Leeb231 are NFe-only; dual models cover mixed steel and aluminium work.
Automotive and panel beating
Measuring paint thickness around a vehicle body reveals refinished or filled panels, because repaired areas read noticeably thicker than factory paint. A dual gauge is useful here because many modern vehicles combine steel and aluminium panels.
Pipelines, tanks and marine steel
Coating gauges verify the epoxy, polyurethane or rubber lining on pipe, tank and hull steel. They do not measure the steel wall itself; that needs an ultrasonic gauge (see below). The two are often used together during the same inspection.
Coating thickness gauge vs ultrasonic thickness gauge
Both are called "thickness gauges", but they answer different questions.
| Coating thickness gauge | Ultrasonic thickness gauge | |
|---|---|---|
| Measures | The coating on top of a metal | The material itself: pipe wall, plate, tank shell |
| Principle | Magnetic induction or eddy current | Time of flight of an ultrasonic pulse |
| Typical units | µm (microns) | mm |
| Typical question | "Is there enough paint or zinc on this steel?" | "How much steel is left after corrosion?" |
| Leeb models | This page | UEE930, UEE932, UEE962 |
Ecotao lists Leeb ultrasonic thickness gauges on its online store: the UEE930, UEE932 and UEE962, alongside the wider thickness gauge range.
Coating thickness measurement in South Africa
South Africa's coastline is a demanding environment for coated steel. Salt-laden air around Cape Town, Durban, Richards Bay, Gqeberha and Saldanha puts structures in higher atmospheric corrosivity categories under SANS 12944 (ISO 12944), and those categories drive thicker specified coating systems. Checking that the specified thickness was actually applied is the cheapest point at which to prevent early corrosion.
The measurement methods Leeb gauges use are the ones described in the main coating-measurement standards South African specifications reference:
- ISO 2178: magnetic method for non-magnetic coatings on magnetic substrates (Fe mode).
- ISO 2360: eddy-current method for non-conductive coatings on non-magnetic metals (NFe mode).
- SANS 121 / ISO 1461: minimum hot-dip galvanised coating thicknesses on fabricated steel.
- ASTM D7091 and ISO 19840: how to take and assess dry film thickness readings on protective coatings.
Always check which standard and acceptance criteria your project specification calls for. Ecotao delivers throughout South Africa and to Namibia, Botswana, Zimbabwe, Mozambique, Lesotho and Eswatini from our Cape Town base.
Looking for the Leeb210, 220, 221, 222, 250 or 251?
These models are no longer listed by Leeb. The closest current equivalents are:
| Older model | Principle | Closest current option |
|---|---|---|
| Leeb210, Leeb220 | Fe | Leeb230, or UEE920 with Fe probe |
| Leeb221 | NFe | Leeb211 or Leeb231 |
| Leeb222 | Fe & NFe | Leeb232 or UEE920 |
| Leeb250 | Fe (built-in probe) | Leeb252 (dual) or Leeb253 (thick film) |
| Leeb251 | NFe (built-in probe) | Leeb252 |
If you are replacing probes or calibration specimens for an older gauge, contact Ecotao with the model number and we will check what is still available.
Coating thickness gauge questions
What is the difference between a Fe and an NFe coating thickness gauge?
A Fe gauge uses magnetic induction and measures non-magnetic coatings (paint, powder coat, zinc, chrome, rubber) on magnetic steel and iron. An NFe gauge uses eddy currents and measures non-conductive coatings (paint, plastic, anodising) on non-magnetic metals such as aluminium, copper and zinc. A dual Fe/NFe gauge does both. On most Leeb dual models you fit the Fe or NFe probe for the job; the compact Leeb252 has a single built-in probe and one-button operation.
Can a coating thickness gauge measure steel wall or plate thickness?
No. Magnetic induction and eddy-current gauges measure only the coating on top of the metal. To measure the remaining wall thickness of a pipe, tank, hull or plate you need an ultrasonic thickness gauge. Ecotao lists the Leeb UEE930, UEE932 and UEE962 ultrasonic thickness gauges on its online store.
Which Leeb gauge should I use for hot-dip galvanising?
Zinc is a non-magnetic coating on a steel substrate, so any Fe-capable Leeb gauge will measure it. Galvanised coatings usually fall well within the 0 to 1250 µm range. For inspections where readings must be recorded against SANS 121 (ISO 1461) minimum mean thicknesses, a model with memory, statistics and PC transfer such as the UEE920, UEE922 or Leeb242 makes reporting easier.
Which Leeb gauge measures thick intumescent fireproof coatings?
The Leeb253. It is a magnetic induction gauge with a 0 to 6000 µm range, and Leeb describes it as intended specifically for fireproof coatings. Every other current Leeb coating gauge stops at 1250 µm.
How accurate is a Leeb coating thickness gauge?
Leeb states accuracy as a formula based on the coating thickness H. Most models are rated ±[(1–3%)H + 1] µm, which at a 100 µm coating is roughly ±2 to ±4 µm. The UEE920 and UEE922 are rated ±(2%H + 1) µm (about ±3 µm at 100 µm) and the UEE923 is rated ±(1%H + 1) µm (about ±2 µm at 100 µm). These figures assume calibration on the actual substrate using the supplied specimens.
What are the minimum part size limits for a coating thickness gauge?
For most Leeb models the measuring area must be at least 7 mm in diameter, the substrate at least 0.5 mm thick, convex curves no tighter than 1.5 mm radius and concave curves no tighter than 9 mm. The Leeb252 and Leeb253 need a 10 mm area and 20 mm concave radius.
Which Leeb coating gauges can print or send readings to a PC?
The UEE923 has a built-in thermal printer. The Leeb242 and Leeb262 print wirelessly to the supplied micro-printer and connect to a PC by USB. The UEE920 and UEE922 have PC software and USB but no printer. Ask Ecotao about data output on the other models.
What replaced the Leeb210, 220, 221, 222, 250 and 251?
These models are no longer listed by Leeb. The closest current equivalents are the Leeb230 or UEE920 for Fe work, the Leeb211 or Leeb231 for NFe work, the Leeb232 or UEE920 for dual Fe/NFe work, and the Leeb252 for a compact one-button gauge. Contact Ecotao to match a replacement to your application.
Need help choosing a coating thickness gauge?
Tell us the substrate, the coating and the thickness you need to verify, and we will recommend the right Leeb model and confirm availability and delivery.
- Zak: 086 142 8716
- Zaid: 082 390 3989
- aqua@ecotao.co.za
- 39 Olienhout Avenue, Plattekloof, Cape Town