Oil and grease detection? It is much easier than ever before!

Recognoil® 2W, an unique wireless electronic fluorescence analyzer gauge, used for oil and grease detection, replaces obsolete, nonobjective and demanding testing methods of contaminated surfaces. Optical-electronic analysis is used - luminescence of contaminants is monitored and then transformed with Recognoil® 2W software into digital image output.

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In the 21st century, demand for precise and reliable information in real time, in simple, repeatable and reproducible form, with an easy interpretation and further analysis of obtained data is the highest priority in engineering connected with the development of information technology. It applies to oil and grease detection in the field of surface treatment, manufacturing of optical systems, electrical engineering and other branches where oil and grease contamination may occur – either desirable or undesirable. Recognoil® 2W, precise, wireless and sensitive electronic fluorescence analyzer gauge, meets the demand and is able to do much more.

Recognoil® 2W gauge by TechTest s.r.o. provides analysis and information in real time in the form of image output (2D and 3D) as well as the percentage of oil/grease deposits, layer thickness and the cause of contamination such as fingerprints. The principle of detection is based on the induction of the luminescence of contaminants, their capture and subsequent evaluation using the supplied software. The device is also equipped with a set of LEDs and audible alarm allowing a separate measurement without being connected to a PC or tablet with determining the admissibility of contamination of the surface by a pre-set limit.


Oil Deposition Checks

Oil deposition and degreasing checks, primarily of steel and aluminium materials.


Trace oil contamination detection

Trace oil contaminants can be detected on metal surface.


3-D Model Output

Three-dimensional analysis of the layout and intensity of a contaminated surface.


Live Mode

Able to scan in real time when moving the device across the surface, ideal for random checks.



Wireless gauge uses WiFi for data transfer.


Process limits

Determination of surface purity with OK / NOT OK limits.


Process Optimization

The output indicates whether your technology process is fine-tuned or not.


Image Browser

With an intuitive browser, manage and share your captured images (mark critical points, surface pollution concentration, fluorescence value, thickness etc.).


Thickness Calculation

Conversion of the detector output to the surface concentration of the oil [mg.m2] or film thickness [nm].


Info LED panel

A set of LEDs and audible signals allows independent measuring without connection to PC or tablet.



Possibility to create statistical calculations from individual measurements for even more accurate outputs


Great outputs

Creating clear reports, archiving data, and documenting the production process.


Fluorescence value detected by Recognoil® 2W gauge, which depends on the amount of residual oil substances left on the surface, indicates the quality of degreasing process. The lower the value, the cleaner the surface is. Thanks to this value, it is possible to simply and easily tune the degreasing process parameters and effectively set the degreasing time needed to fulfill the required cleanliness class demand. Even trace amounts of oil contamination will be discovered by Recognoil® 2W gauge.


Another case is the application of a uniform layer of oil film. Fluorescence value increase detected by the device is in correlation with the deposited oil thickness. In advanced versions, the software automatically transfers the fluorescence values directly to layer thickness [nm] values or surface concentration [mg.m-2] with the help of a physical-mathematical model of the oil (created by lab sampling calibration).

Technical Data

Device name: Recognoil® 2W
Detection method: non-destructive, optical - contactless
Principle of function: excitation of impurities by UV radiation and evaluation of the image of their fluorescence intensities
Size of the evaluated area: 20.0 x 13.8 mm
Sensor Resolution: 1,536 x 1,056 px / 1 px corresponds to approximately 13 μm (PROFESSIONAL), 768 x 528 px (STANDARD)
Measuring and evaluation time: 1 second to max. 10 seconds, depending on type of greasy dirt and light conditions
Detection limit: minimum area concentration of about 15 to 70 mg.m2 (approx. 16 to 77 nm layer thickness), according to the type of greasy dirt and roughness of the substrate, the range can be arbitrarily adjusted to layer thickness up to approx. 4-10 μm
UV wavelength / power: 365 nm / 1 000 mW

Electrical voltage maximum: 9V DC
Battery: Li-Ion 3.7V / 3,400 mAh, lifetime of 500 no-charge detection (depending on exposure time
Charging the battery: using USB - mini
Required Hardware: notebook / Tablet with Windows 7/8/10 - not for android tablets
Supplied software: desktop application for MS Windows for operating, setting, evaluating and managing data
Interface Type: wireless, WiFi - handheld Recognoil® 2W gauge acts as an access point (AP) to which a tablet / notebook / PC connects
Weight of the device: 356 g
Dimensions 130.0 x 212.0 x 33.5 mm

Supplied software

Although Recognoil® 2W can be used to determine the surface quality without having to connect to a PC, it is necessary to use the SW interface to set the evaluation limits, which, according to the selected option, allows the operator to obtain a whole range of useful information, data and outputs. The basic software version of STANDARD is delivered free of charge, and the purchase of a higher version of the SW is possible at any time according to the customer‘s needs. The different variants are different in the possibilities of processing and managing the measured data, however, the detection capabilities of the device remain unchanged.


This option allows you to set 3 measuring modes - presets with limits (OK / NOT OK) to subsequently evaluate the surface quality without using a PC or tablet (audio-visual signaling). Each exposure using the gauge is fully automatic, and the results are stored in the device memory. This data can then be downloaded using the SW interface, evaluated and exported in JPG format. Measurements can also be made online when data is transferred to SW via Wi-Fi. SW allows to display fluorescence maps (distribution of contaminants) in SD resolution 768 x 528 px, fluorescence intensity of the whole area [-] and selected local areas [-]. With the OK / NOT OK parameter set, the output is also the relative size of the area [%] exceeding the set maximum limit.


The PROFESSIONAL SW version also allows the determination of total and local area concentrations [mg.m-2] and thickness [nm] of oil film after previous laboratory oil calibration. With this option, 3 oil calibrations are included in the price. Moreover, this software option allows 3D imaging of surface contamination, manual exposure settings, creating statistical measurements data and the possibility of exporting PDF and XLS. The fluorescence map resolution can be adjusted to SD and HD (1,536 x 1,056 px) as needed. The package also includes an ambient light eliminator module for imperfect shading. Part of the instrument is also a validation standard for verifying the accuracy of the measurement results. The package includes a source file manager that allows project organization, histogram display, and bulk export.


INDIVIDUAL software represents a solution to the specific customer requirements. For example, SW allows automatic detection of objects or locations on the surface to be measured. SW suitable for operators, quality control or laboratory. First of all, it is the implementation of user functions, statistical calculations and data export. Individual solution can also be a variant that allows fully automated measurement of whole parts or online transmission of data to Cloud or other storage. We also offer the production of detection devices according to the customer's requirements (eg devices for operators, unattended control devices installed in automated lines, etc.) For more information on individual solutions do not hesitate to contact us.

FAQ - Frequently Asked Questions

To get fully trusted results and outcomes from the Recognoil® 2W gauge, it is important to get to know the basic principles of device operation.

How does the device work?

The gauge irradiates the surface with invisible and undetectable UV light. The certain physical and chemical properties of the residual grease and oils force the chemical elements and molecules to emit visible light. This natural phenomenon is called fluorescence. The UV source, as mentioned above, emits invisible and undetectable radiation. On the other hand, the detector then receives the outcomes of the fluorescence process, which emit radiation in the domain of visible light. If there is a light coming in from the environment, not originating from the process of fluorescence, it interferes with the fluorescence signal and disrupts the detection. For this reason, detections need 100% light-free environment. The detector consists of a small detecting plate, which converts the incident light into electrical signal, which is then analyzed by the software. Because of the need of transferring the light from a bigger surface onto this very small detecting plate, a set of lens must focus the incoming light. Every lens has a focusing point. The Recognoil device has a fix focusing point, which cannot be changed. The second limitation limits the allowed distance of the object within +/- 3 mm far from the focusing point.

Can I use a device without a PC or tablet?

Recognoil® 2W is equipped with an LED and audible alarm, allowing for independent measurement without the need to connect to a PC or tablet with the possibility of determining the admissibility of the surface contamination according to a pre-set limit. The visual orientation of the operator is based on pictograms on the LED panel. The operator may have 3 limits (for different surfaces, process steps, etc.) loaded in the device, which can be activated by the multifunctional shutter button of the device. All exposures are stored in the device's memory - the operator can later download all measured datas, pictures, make protocols, etc.

Can Recognoil® 2W capture shape-complex surfaces?

The oil film detections of these objects may suffer from poor focus of the detector. Due to this issue, we recommend using a special-designed adapter, copying the surface curvature and setting the right focusing distance. If it is necessary to precisely document the entire part (ie an area larger than 20.0 x 13.8 mm), it is necessary to perform automated sequential scanning. This is ac-complished by placing the object in a dark box and scanned using a detector clamped on a computer-controlled portal. The entire area is gradually measured in the grid and the output is a SW composite image of the individual fluorescent maps of the product.

For what basic materials can the device be used?

Recognoil® 2W can be used with almost all oil types and lubricant residues, which contain a part of a synthetic compound. It is not suitable for very refined mineral oils – these applications often require a fluorescence agent. The Recognoil device is not suitable for use with silicone oil based compounds. Besides the aforementioned oils and greases, which can easily be detected by this principle, exhibit fluorescence for example: dust, paper, plastics, etc. Suitable base materials are especially metals (no fluorescence of the clean surface). The instrument can be used on plastics, glass, ceramics etc. on the basis of the verification of the properties of the material (or its composition, surface treatment etc.). The table below gives recommendations on the suitability of the method based on the combination of test material and the type of the contamination.

What are the measured units?

the standard output of the device is the mean value of the output of the detector (the so-called fluorescence intensity), so for interpreting the results we use F.U. - (fluorescence units). Recognoil® 2W does not allow for the method of detection of greasy contamination to determine the surface tension value in mN.m-1. However, it is possible to determine the surface tension value corresponding to the F.U. under suitable conditions (after experimental determination).

Is there any universal surface cleanness value?

For specific applications, the surface contamination limit [F.U.] suitable for the intended application can not be predetermined. Determination should be based on validation tests. It is very easy to determine the value of F.U. for perfectly degreased metal surfaces. From this value, the surface condition and its contamination can be subsequently monitored. It should also be borne in mind that different types of oils exhibit different fluorescence. Thus, for example, in the case of 10,000 F.U. for one type of oil and 100,000 F.U. for the other it is not possible to talk in advance about different layer thicknesses or area concentrations. These values due to the principle of the detection method must be determined using the mathematical model of the oil based on laboratory calibration.

Examples of use?

For the purposes of demonstration, we can suggest 4 spheres of the Recognoil® 2W gauge application.

Example 1 – a paint shop
The Recognoil® 2W gauge serves as a quick random check of the surface degreasing quality. The operator has already found out, what limit settings are appropriate for the type of object being detected. A value of detector output, together with a per cent value, which shows how big part of the surface has grease / oil amounts exceeding the limit, are displayed 2 seconds after the trigger has been pressed.

Example 2 – a laboratory
A laboratory would need to know exact surface concentrations and layer thicknesses. For this reason, the one and only oil / grease type must be present on the surface and the substance must be “sampled” in our laboratory. After this sampling process, we send an “oil file”, which is then imported into the software and the results are from that time represented in surface concentrations and layer thicknesses.

Example 3 – sheet metal factory
In a sheet metal factory equipped with a degreasing line, an operator would check at which state the material goes into the degreasing line and then would check the output. The operator has already the knowledge, how much DO (detector output) shows the Recognoil® 2W device after degreasing at a normal state. When the device begins to show greater numbers and shows areas of brighter colors on the display (selective accumulation of the grease residues), it is a warning for the operator, that the degreasing line is faulty.

Example 4 - cleanrooms
In plants where great emphasis is placed on the extreme surface cleanliness (dust, grease, etc.), the Recognoil® 2W can be used to control these areas without contamination. Using Live View (LIVE mode), you can quickly locate the contaminant and perform a standard evaluation to determine the degree of contamination.

Why use Recognoil® 2W?

Recognoil® 2W enables a completely objective and reproducible determination of surface contamination. You can also quantify the obtained samples and archive the outputs for further use. In the case of complaints, you can use the outputs from the instrument to prove the actual surface condition of the part in the individual technological steps. For this reason, it is a method suitable for quality management systems and due to the connectivity of the device and the capabilities of SW solutions for Industry 4.0.


Control of degrease quality on surfaces contaminated with oil after the previous forming operations.

Determination of the detection limit based on the adhesion test of the coating.

Check of entire objects.

Control of the quantity and uniform distribution of the oil film.

Determining the surface condition of specific functional areas of objects.

Surface contamination caused by non-technological discipline.

Determination of various defects of the coatings (imperfections, particles, etc.).

Shape-complex surfaces check.

Covers with negative shape of objects​.


Files for download.


Are you interested in Recognoil® 2W device? Are you interested in our services? For more information please contact us any time!

+420 774 452 995 - Ing. Petr Chabera
+420 724 234 699 - Ing. Michal Zoubek
+420 605 868 932 - Ing. Jan Kudlacek, Ph.D.
+420 605 305 171 - Ing. Jakub Svoboda

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