CZ307047B6 - A water-washable emissive paint for non-contact temperature measurement of objects by infrared detection and a method of using this paint - Google Patents

Description

Technical field

The invention relates to the field of non-contact temperature measurement of objects, and more particularly to a water-washable emissive ink for non-contact temperature measurement of objects by detecting infrared radiation, and a process for using the color.

BACKGROUND OF THE INVENTION

In industry, construction, science and research, methods of contactless temperature measurement of objects using infrared detection of these objects are currently widely used. Although they have a number of advantages consisting mainly in the non-contact character of the measurement, a wide range of measured temperatures and the possibility of measuring temperatures and moving objects, their main disadvantage is the dependence of the measured temperature value on the emissivity of the measured object surface. This emissivity, together with the object's temperature, determines the level of infrared radiation it emits.

It is known to solve this disadvantage by coating the surface of the measured object with emissive dyes. These colors have high emissivity and low permeability. They also have high adhesion, even at high temperatures, which results in the disadvantage of their difficult, complex and laborious removal from the surface of the measured object. For this purpose, coarse mechanical methods or aggressive chemical agents are used, which can damage the surface of the object. For many surfaces where these methods cannot be used and which cannot be permanently coated for functional or aesthetic reasons, these colors are not applicable.

SUMMARY OF THE INVENTION

These drawbacks are substantially eliminated by a water-washable emissive dye for contactless temperature measurement of objects by detecting infrared radiation, having an emissivity value in the range of 0.93 to 0.98, and a process for using the dye according to the invention, the nature of which is wherein the color comprises 65 to 95 wt. % carrier substances consisting of primary and secondary alcohols having a carbon chain length of at most five carbon atoms, 1 to 12 wt. % carbon black or carbon black with a low organic matter or graphite content and 3 to 28 wt. calcium or magnesium carbonate, or combinations thereof.

Suitably, the primary and secondary alcohols have two to four carbon atoms in the chain and have a branched chain.

In the case of ground graphite, the ground particle size must be at most 1/20 of the nozzle diameter, but at most 30 µm.

Calcium or magnesium carbonate is either precipitated or ground to a particle size of not more than 1/20 of the nozzle diameter, but not more than 30 μιη.

Natural ground limestone, magnesia and dolomite can be used for ground calcium or magnesium carbonate.

In the process of using a water-washable emissive paint for contactless temperature measurement of objects by detecting infrared radiation, the invention consists in uniformly applying a paint layer to the dry and cleaned surface of the object and, after drying, a second layer of paint

The layer of this color is dried and after its drying the contact temperature measurement of the object is detected by detecting infrared radiation of the surface of the measured object.

After the measurement is finished, the paint is removed from the surface of the measured object with water, possibly using soap or detergent.

It is advantageous to apply the paint to the surface of the object by means of a spray.

The color for contactless temperature measurement by infrared detection according to the invention achieves the emissivity values (0.93 to 0.98) and the transmittance (0.005 to 0.1) required for the wavelength band from 2 to 15 μιη for conventional thermal imaging cameras used in contactless temperature measurement. In addition, the paint according to the invention is water-washable, non-toxic and free of hazardous chemicals. The procedure for using this paint is simple, requiring no specific mechanical, thermal or chemical finishes other than cleaning and drying the surface. Drying and application are carried out at normal room temperatures.

To improve dispersion, carbon black, carbon black and graphite are surface-treated with polar functional groups to anionic, in particular hydroxyl, carboxyl, amine and quaternary ammonium functional groups, or supplemented with surfactants of ionic or nonionic character in amounts up to 0.2 wt.

In one possible embodiment, the color for contactless temperature measurement of the objects comprises 65 wt. % carrier substances in the form of primary and secondary branched chain alcohols having a carbon chain length of four carbon atoms; % carbon black and 22 wt. mixtures of calcium carbonate and magnesium carbonate in ground form.

DETAILED DESCRIPTION OF THE INVENTION

In a first embodiment of the invention, the water-washable paint for contactless temperature measurement of objects comprises 95 wt. % isopropanol carrier, 2 wt. % carbon black and 3 wt. calcium carbonate in ground form.

According to a second embodiment of the invention, the paint for contactless temperature measurement of objects comprises 80 wt. % ethanol carrier, 7 wt. % carbon black and 13 wt. magnesium carbonate in ground form.

To improve dispersion, carbon black, carbon black and graphite may be surface-treated with suitable functional groups of polar nature or supplemented with surfactants of ionic or non-ionic nature in amounts of up to 0.2% by weight.

As far as the application of this paint is concerned, it is necessary to remove the surface, respectively from the surface, from dry and all impurities and solid parts. part of the surface of the object is evenly applied a layer of paint. After drying, a second layer of paint is applied and after drying of the second layer, contactless measurement of the object temperature is performed by detecting the infrared radiation of the surface of the object to be coated. The paint is preferably applied by spray, but it is also possible to use a paint brush. After the measurement is finished, the paint is removed from the surface of the measured object with water, possibly using soap or detergent.

Industrial applicability

The invention is applicable to any non-contact temperature measurement of objects, eg by thermovision or pyrometer, except for measurement in a water or steam environment, since the color used is water soluble.

Claims (8)

PATENT CLAIMS A water-washable emissive paint for contactless temperature measurement of objects by detecting infrared radiation, having an emissivity value in the range of 0.93 to 0.98, characterized in that it contains 65 to 95 wt. % carrier substances consisting of primary and secondary alcohols having a carbon chain length of at most five carbon atoms, 1 to 12 wt. % carbon black or carbon black with a low organic matter or graphite content and 3 to 28 wt. calcium or magnesium carbonate, or combinations thereof. 2. The ink of claim 1, wherein the primary and secondary alcohols have two to four carbon atoms in the chain and are branched. Paint according to claim 1 or 2, characterized in that the graphite is ground with a particle size of at most 1/20 of the nozzle diameter, but at most 30 µm. Paint according to any one of claims 1 to 3, characterized in that the calcium or magnesium carbonate is either precipitated or ground to a particle size of at most 1/20 of the nozzle diameter, but at most 30 µm. Paint according to claim 4, characterized in that natural limestone, magnesite and dolomite can be used for the ground calcium or magnesium carbonate. Method for the use of a water-washable emissive paint for contactless temperature measurement of an object by detecting infrared radiation according to any one of claims 1 to 5, characterized in that a layer of washable emissive paint is uniformly applied to the dry and cleaned surface of the object. of this color and after its drying, the contact temperature measurement of the object is detected by detecting infrared radiation of the surface of the measured object. Method for the use of a paint according to claim 6, characterized in that after completion of the measurement, the paint is removed from the surface of the measured object with water, optionally using soap or detergent. 8. The method for the use of a paint according to claim 6, wherein the application of paint to the surface of the object is accomplished by means of a spray.