Area of application

Coating thickness measurement in the heavy corrosion protection sector

QNix® 8500 and QNix® 4500 make the measurement process easier for users, from making simple measurements to documenting the results.


Around the world, coating companies collaborate with steel manufacturers, paint manufacturers, specialised service companies and engineering offices. By doing so, they can optimise the security, profitability and level of quality of operations, as well as construction and maintenance of steel constructions, machines and equipment in a wide variety of sectors. The precise, robust and easy-to-use coating thickness gauges from QNix® help users during this process.



Display with two coating thickness measured values

Modern coating materials effectively protect against corrosion, especially when applied in several layers. Critical steel constructions, such as bridges and offshore constructions, are protected using a duplex coating system based on hot-dip galvanising and a 2K-epoxy coating.


The QNix® 8500’s combined measurement mode makes it possible to measure the layer thickness of the hot-dip galvanising and the epoxy-based coating on the steel substrate in a single measurement process. The device then displays the thickness of the zinc layer and the paint layer as separate values (minimum zinc coating thickness: 50 μm).

Measurement data processing and documentation via Excel

A systematic procedure and documentation of work are necessary for performing and monitoring the coating work. To verify individual layers of a coating system, users define control surfaces based on the object size. A defined number of measurements must be performed on these surfaces.


With the software from QNix® and the USB radio adapter, users can transmit the coating thickness measured values to a PC via radio and export them to Excel. That lets them document and process their results quickly, reliably and conveniently.

Reliable coating thickness measurement on rough surfaces

Roughening up surfaces improves the adhesive force of coating systems and is one of the important steps in preparatory work for heavy corrosion protection. However, the surface topography of the basic substrate influences the accuracy of the measurement result. If the device does not compensate for the roughness, it indicates that the layer is thicker than it actually is. When dealing with rough substrate surfaces, you can calculate and store an average zero reference using as many reference measurement values as you like.

In addition to an (immutable) factory calibration, the QNix® 8500 also enables two calibration procedures that can be used to compensate for roughness:

  • A single-point calibration compensates for the roughness for target layer thicknesses.
  • A two-point calibration compensates for the roughness in layer thickness range.

Our recommendations for this area of application

QNix® 8500

  • Extensible, modular device system with interchangeable probes and a measurement range of up to 5000 µm – guarantees later adjustment to the new measurement tasks throughout the entire product lifecycle
  • Users can replace the probe cable
  • High measurement speeds of up to 120 measurements/minute
  • Quick and easy calibration function
  • Duplex measurement mode for measuring multi-layer systems
  • Enough memory for up to 30,000 measurement values in over 200 blocks with a statistics function and PC software  for evaluation and documentation
  • Acoustic and visual display if set minimum and maximum coating thicknesses are either fallen short of or exceeded
  • Durable ruby measurement tip for a large number of measurements
  • An optional rubber cover with velcro fasteners reduces shock sensitivity
  • Optional thumb-sized radio probe with a hand strap facilitates use in places that are difficult to access and takes safety regulations for work safety – such as during lattice tower checks – into consideration

QNix® 4500

  • Compact and simple hand-held gauge for quickly measuring coatings
  • High measurement speeds of up to 110 measurements/minute 
  • Durable ruby measurement tip for a large number of measurements
  • Simple and fast calibration function (zero-point adjustment) on the uncoated original substrate or the reference standards included in the delivery
  • Designs with integrated or cable probe with 5 mm or 3 mm measurement range
  • Measurement on ferrous and non-ferrous metals (Fe and NFe)
  • Also available as a purely Fe gauge

Additional areas of application