Surface condition measurement apparatus

A surface condition measurement apparatus comprising:

• at least one two-color thermometer having an arbitrary position on the surface of a material;
• involution ratio calculation means for calculating an emissivity involution ratio .epsilon..sub.1.sup..lambda.1 /.epsilon..sub.2.sup..lambda.2 from brightness temperatures S1 and S2 for two wavelengths .lambda..sub.1 and .lambda..sub.2, the brightness temperatures obtained from said two-color thermometer, the emissivity involution ratio obtained according to the following expression
• .epsilon..sub..sup..lambda. 1/.epsilon..sub.2.sup..lambda.2 =exp[C2{(1/S2)-(1/S1)}]
• wherein C2 is Planck's second constant;
• first emissivity ratio calculation means for converting the emissivity involution ratio to a first spectral emissivity ratio .epsilon..sub.1 /.epsilon..sub.2 in accordance with the following correlation function
• .epsilon..sub.1 /.epsilon..sub.2 =f(.epsilon..sub.1.sup..lambda.1 /.epsilon..sub.2.sup..lambda.2);
• second emissivity ratio calculation means for separately calculating spectral emissivities .epsilon..sub.1 * and .epsilon..sub.2 * for said two wavelengths .lambda..sub.1 and .lambda..sub.2 using theoretical or experimental expressions having at least one physical value affecting the emissivity, and for calculating a second spectral emissivity ratio .epsilon..sub.1 */.epsilon..sub.2 *;
• search calculation means for giving an initial value to the at least one physical value and for making search calculations for the at least one physical value, the search calculations bringing the second spectral emissivity ratio, calculated using the at least one physical value, substantially into agreement with the first spectral emissivity ratio;
• and
• temperature calculation means for making two-color temperature calculation using one of the first spectral emissivity ratio and the second spectral emissivity ratio, the second spectral emissivity ratio having gone through the search calculations.

A surface condition measurement apparatus comprising:

• at least one two-color thermometer having an arbitrary position on the surface of a material;
• first involution ratio calculation means for calculating a first emissivity involution ratio .epsilon..sub.1.sup..lambda.1 /.epsilon..sub.2.sup..lambda.2 from the brightness temperatures S1 and S2 for the two wavelengths .lambda..sub.1 and .lambda..sub.2 obtained from said two-color thermometer, the first emissivity involution ratio calculated according to the following expression
• .epsilon..sub.1.sup..lambda.1 /.epsilon..sub.2.sup..lambda.2 =exp[C2{(1/S2)-(1/S1)}]
• wherein C2 is Planck's second constant;
• second involution ratio calculation means for separately calculating spectral emissivities .epsilon..sub.1 * and .epsilon..sub.2 * for the two wavelengths using theoretical or experimental expressions having at least one physical value affecting the emissivity, and for calculating a second emissivity involution ratio .epsilon..sub.1.sup.*.lambda.1 /.epsilon..sub.2.sup.*.lambda.2 from the spectral emissivities;
• and
• search calculation means for calculating an initial value of the at least one physical value and for making search calculations for the at least one physical value, the search calculations bringing the second emissivity involution ratio substantially into agreement with the first emissivity involution ratio.

A two-color multiplex type radiation thermometer comprising:

• spectroscopic means for dispersing light into two different wavelengths .lambda..sub.1 and .lambda..sub.2 for each of a plurality of different wavelength zones;
• photoelectric conversion means for measuring brightness temperatures S1 and S2 from the two different wavelengths for each of the wavelength zones;
• involution ratio calculation means for calculating an emissivity involution ratio .epsilon..sub.1.sup..lambda.1 /.epsilon..sub.2.sup..lambda.2 from the brightness temperatures measured from the two different wavelengths for each of the wavelength zones, the emissivity involution ratio obtained according to the expression
• .epsilon..sub.1.sup..lambda.1 /.epsilon..sub.2.sup..lambda.2 =exp[C2{(1/S2)-(1/S1)}]
• wherein C2 is Planck's second constant;
• emissivity ratio calculation means for converting the emissivity involution ratio into a spectral emissivity ratio .epsilon..sub.1 /.epsilon..sub.2 using the correlation function
• .epsilon..sub.1 /.epsilon..sub.2 =f(.epsilon..sub.1.sup..lambda.1 /.epsilon..sub.2.sup..lambda.2);
• temperature calculation means for making two-color temperature calculation using the spectral emissivity ratio and for calculating a measurement temperature;
• and
• wavelength zone selection means for monitoring time variations of one of the emissivity involution ratio and the spectral emissivity ratio for each of the wavelength zones and for selecting a particular wavelength zone based on the monitored time variations, wherein the measurement temperature calculated for said particular wavelength zone is output.

A multi-wavelength type radiation thermometer comprising:

• spectroscopic means for dispersing light into a plurality of different wavelengths .lambda..sub.1 to .lambda..sub.n ;
• photoelectric conversion means for measuring a plurality of brightness temperatures S1 to Sn, each brightness temperature measured at a respective wavelengths .lambda..sub.1 to .lambda..sub.n ;
• involution ratio calculation means for calculating an emissivity involution ratio .epsilon..sub.i.sup..lambda.i /.epsilon..sub.j.sup..lambda.j from the brightness temperatures S1 to Sn obtained on-line for each combination of two different wavelengths according to the expression
• .epsilon..sub.i.sup..lambda.i /.epsilon..sub.j.sup..lambda.j =exp[C2{[C2{(1/Sj)-(1/Si)}]
• wherein i, j are positive integers not exceeding n, i.noteq.j, and C2 is Planck's second constant;
• reference means for storing an (n-1)-dimensional involution ratio regression function, the (n-1)-dimensional involution ratio regression function made from one of off-line measurement data and theories, for expressing mutual relationships of emissivity involution ratios, an (n-1)-dimensional emissivity ratio regression function expressing mutual relationships of emissivity ratios .epsilon..sub.1 /.epsilon..sub.j, and for converting the involution ratio regression function into the emissivity ratio regression function;
• judgment means for determining a point on the emissivity involution ratio regression function corresponding to (n-1)-dimensional coordinates formed of (n-1) emissivity involution ratios calculated from the above expression, the judgment means using the brightness temperatures S1 to Sn obtained on-line;
• conversion means for applying said mapping to a determined point on the involution ratio regression function to convert the determined point to a converted point on the emissivity ratio regression function and for calculating (n-1) emissivity ratios .epsilon..sub.1 /.epsilon..sub.j from the converted point;
• and
• temperature calculation means for calculating a measurement temperature by making temperature calculation using at least one of the calculated emissivity ratios.