OUTPUT METHOD FOR ELECTRONIC WBGT METER, AND ELECTRONIC WBGT METER

Abstract

An electronic WBGT meter obtains a WBGT index reflecting wind velocity and radiation. A first calculation unit obtains an arbitrary-diameter globe temperature of the electronic WBGT meter with respect to each of specific thermal environments, and a second calculation unit obtains a standard-diameter globe temperature of ISO-compliant WBGT meter with respect to each of the specific thermal environments. A third calculation unit obtains a natural wet-bulb temperature with respect to each of the specific thermal environments. A correlation determination unit determines a correlation of the air temperature, the arbitrary-diameter globe temperature, and the relative humidity with corresponding the standard-diameter globe temperature and the natural wet-bulb temperature. A measurement calculation element storing the correlations is mounted in the electronic WBGT meter under a real thermal environment, and calculates the standard-diameter globe temperature and the natural wet-bulb temperature of ISO-compliant WBGT meter.

Claims

1-17. (canceled)

18. A method for correlating measured values of an electronic WBGT meter with measured values of an ISO-compliant WBGT meter, comprising steps of: obtaining an arbitrary-diameter globe temperature of the electronic WBGT meter with respect to each of specific thermal environments, based on air temperatures, average radiation temperatures, and wind velocities under the specific thermal environments; obtaining a standard-diameter globe temperature of the ISO-compliant WBGT meter with respect to each of the specific thermal environments, based on the air temperatures, the average radiation temperatures, and the wind velocities under the specific thermal environments; obtaining a natural wet-bulb temperature of the ISO-compliant WBGT meter with respect to each of the specific thermal environments, based on the air temperatures, the average radiation temperatures, the wind velocities, and relative humidities under the specific thermal environments; and determining a correlation between input and output, based on an input data group for inputting the air temperature, the arbitrary-diameter globe temperature, and the relative humidity with respect to each of the specific thermal environments, and an output data group for outputting the standard-diameter globe temperature and the natural wet-bulb temperature corresponding thereto.

19. The method for correlating the measured values of the electronic WBGT meter with measured values of the ISO-compliant WBGT meter according to claim 18, wherein the correlation is determined by learning the input and output data groups as learning data.

20. The method for correlating the measured values of the electronic WBGT meter with measured values of the ISO-compliant WBGT meter according to claim 18, wherein the correlation is determined by obtaining an approximate equation that is completed between the input and output data groups.

21. A device for correlating measured values of an electronic WBGT meter with measured values of an ISO-compliant WBGT meter, wherein the electronic WBGT meter includes a thermometer, an arbitrary-diameter globe temperature and a relative hygrometer, which comprising, a first calculation unit for obtaining an arbitrary-diameter globe temperature of the electronic WBGT meter with respect to each of specific thermal environments, based on air temperatures, average radiation temperatures, and wind velocities under the specific thermal environments; a second calculation unit for obtaining a standard-diameter globe temperature of the ISO-compliant WBGT meter with respect to each of the specific thermal environments, based on the air temperatures, the average radiation temperatures, and the wind velocities under the specific thermal environments; a third calculation unit for obtaining a natural wet-bulb temperature of the ISO-compliant WBGT meter with respect to each of the specific thermal environments, based on the air temperatures, the average radiation temperatures, the wind velocities, and relative humidities under the specific thermal environments; and a correlation determination unit for determining a correlation between input and output based on an input data group for outputting the air temperature, the arbitrary-diameter globe temperature, and the relative humidity with respect to the specific thermal environments, and an output data group for outputting the standard-diameter globe temperature and the natural wet-bulb temperature corresponding thereto.

22. The device for correlating measured values of the electronic WBGT meter with measured values of the ISO-compliant WBGT meter according to claim 21, wherein the correlation determination unit determines the correlation by learning the input and output data groups as learning data.

23. The device for correlating measured values of the electronic WBGT meter with measured values of the ISO-compliant WBGT meter according to claim 21, wherein the correlation determination unit determines the correlation by obtaining an approximate equation that is completed between the input and output data groups.

24. An output method of an electronic WBGT meter comprising steps of: obtaining an arbitrary-diameter globe temperature of the electronic WBGT meter with respect to each of specific thermal environments, based on air temperatures, average radiation temperatures, and wind velocities under the specific thermal environments; obtaining a standard-diameter globe temperature of the ISO-compliant WBGT meter with respect to each of the specific thermal environments, based on the air temperatures, the average radiation temperatures, and the wind velocities under the specific thermal environments; obtaining a natural wet-bulb temperature of the ISO-compliant WBGT meter with respect to each of the specific thermal environments, based on the air temperatures, the average radiation temperatures, the wind velocities, and relative humidities under the specific thermal environments; determining a correlation between input and output, based on an input data group for inputting the air temperature, the arbitrary-diameter globe temperature, and the relative humidity with respect to each of the specific thermal environments, and an output data group for outputting the standard-diameter globe temperature and the natural wet-bulb temperature corresponding thereto; and obtaining a standard-diameter globe temperature and a natural wet-bulb temperature of an ISO-compliant WBGT meter from a real air temperature, an arbitrary-diameter globe temperature and a relative humidity measured by the electronic WBGT meter, based on the correlation.

25. The output method of an electronic WBGT meter according to claim 24, wherein the correlation is determined by learning the input and output data groups as learning data or wherein the correlation is determined by obtaining an approximate equation that is completed between the input and output data groups.

26. The output method of the electronic WBGT meter comprising the steps of: obtaining an arbitrary-diameter globe temperature of the electronic WBGT meter with respect to each of specific thermal environments, based on air temperatures, average radiation temperatures, and wind velocities under the specific thermal environments; obtaining a standard-diameter globe temperature of the ISO-compliant WBGT meter with respect to each of the specific thermal environments, based on the air temperatures, the average radiation temperatures, and the wind velocities under the specific thermal environments; obtaining a natural wet-bulb temperature of the ISO-compliant WBGT meter with respect to each of the specific thermal environments, based on the air temperatures, the average radiation temperatures, the wind velocities, and relative humidities under the specific thermal environments; determining a correlation between input and output, based on an input data group for inputting the air temperature, the arbitrary-diameter globe temperature, and the relative humidity with respect to each of the specific thermal environments, and an output data group for outputting the standard-diameter globe temperature and the natural wet-bulb temperature corresponding thereto; obtaining a standard-diameter globe temperature and a natural wet-bulb temperature of an ISO-compliant WBGT meter from a real air temperature, an arbitrary-diameter globe temperature and a relative humidity measured by the electronic WBGT meter, based on the correlation; and calculating a WBGT index from the real air temperature, and the standard-globe temperature and the natural wet-bulb temperature of the ISO-compliant WBGT meter.

27. The output method of the electronic WBGT meter according to claim 26, wherein the correlation is determined by learning the input and output data groups as learning data or wherein the correlation is determined by obtaining an approximate equation that is completed between the input and output data groups.

28. An electronic WBGT meter including a thermometer, an arbitrary-diameter globe temperature and a relative hygrometer, which comprising, a first calculation unit for obtaining an arbitrary-diameter globe temperature of the electronic WBGT meter with respect to each of specific thermal environments, based on air temperatures, average radiation temperatures, and wind velocities under the specific thermal environments; a second calculation unit for obtaining a standard-diameter globe temperature of the ISO-compliant WBGT meter with respect to each of the specific thermal environments, based on the air temperatures, the average radiation temperatures, and the wind velocities under the specific thermal environments; a third calculation unit for obtaining a natural wet-bulb temperature of the ISO-compliant WBGT meter with respect to each of the specific thermal environments, based on the air temperatures, the average radiation temperatures, the wind velocities, and relative humidities under the specific thermal environments; a correlation determination unit for determining a correlation between input and output based on an input data group for outputting the air temperature, the arbitrary-diameter globe temperature, and the relative humidity with respect to the specific thermal environments, and an output data group for outputting the standard-diameter globe temperature and the natural wet-bulb temperature corresponding thereto; and a measurement calculation element for obtaining a standard-diameter globe temperature and a natural wet-bulb temperature from a real air temperature, an arbitrary-diameter globe temperature, a relative humidity under a real thermal environment, based on the correlation determined by the correlation determination unit.

29. The electronic WBGT meter according to claim 28, wherein the correlation determination unit determines the correlation by learning the input and output data groups as learning data or wherein the correlation determination unit determines the correlation by obtaining an approximate equation that is completed between the input and output data groups.

30. An electronic WBGT meter including a thermometer, an arbitrary-diameter globe temperature and a relative hygrometer, which comprising, a first calculation unit for obtaining an arbitrary-diameter globe temperature of the electronic WBGT meter with respect to each of specific thermal environments, based on air temperatures, average radiation temperatures, and wind velocities under the specific thermal environments; a second calculation unit for obtaining a standard-diameter globe temperature of the ISO-compliant WBGT meter with respect to each of the specific thermal environments, based on the air temperatures, the average radiation temperatures, and the wind velocities under the specific thermal environments; a third calculation unit for obtaining a natural wet-bulb temperature of the ISO-compliant WBGT meter with respect to each of the specific thermal environments, based on the air temperatures, the average radiation temperatures, the wind velocities, and relative humidities under the specific thermal environments; a correlation determination unit for determining a correlation between input and output based on an input data group for outputting the air temperature, the arbitrary-diameter globe temperature, and the relative humidity with respect to the specific thermal environments, and an output data group for outputting the standard-diameter globe temperature and the natural wet-bulb temperature corresponding thereto; a measurement calculation element for obtaining a standard-diameter globe temperature and a natural wet-bulb temperature from a real air temperature, an arbitrary-diameter globe temperature, a relative humidity under a real thermal environment, based on the correlation determined by the correlation device; and a WBGT calculation unit for calculating the WBGT index based on the standard-diameter globe temperature, the natural wet-bulb temperature, and the air temperature.

31. The electronic WBGT meter according to claim 30, wherein the correlation determination unit determines the correlation by learning the input and output data groups as learning data or wherein the correlation determination unit determines the correlation by obtaining an approximate equation that is completed between the input and output data groups.

32. An electronic WBGT meter including a thermometer, an arbitrary-diameter globe thermometer, and a relative humidity hygrometer, which comprising, a measurement calculation element storing a correlation between data groups of the electronic WBGT meter and data groups of an ISO-compliant WBGT meter, inputting a real air temperature, an arbitrary-diameter globe temperature and a relative humidity under a real thermal environment; and obtaining a standard-diameter globe temperature and a natural wet-bulb temperature of the ISO-compliant WBGT meter, wherein, each of the data groups of the electronic WBGT meter including an arbitrary-diameter globe temperature of the electronic WBGT meter, an air temperature, and a relative humidity obtained in respect with each of specific thermal environments based on air temperatures, average radiation temperatures, and wind velocities under the specific thermal environments, each of the data groups of the ISO-compliant WBGT meter including a standard-diameter globe temperature of the ISO-compliant WBGT meter obtained with respect to each of the specific thermal environments based on the air temperatures, the average radiation temperatures and the wind velocities under the specific thermal environments, and a natural wet-bulb temperature obtained with respect to each of the specific thermal environments based on the air temperatures, the average radiation temperatures, the wind velocities, and relative humidities under the specific thermal environments.

33. The electronic WBGT meter according to claim 32, further comprising, a correlation determination unit determines the correlation by learning the input and output data groups or a correlation determination unit determines the correlation by obtaining an approximate equation that is completed between the input and output data groups.

34. The electronic WBGT meter including a thermometer, an arbitrary-diameter globe thermometer, and a relative humidity hygrometer, which comprising, a measurement calculation element storing a correlation between data groups of the electronic WBGT meter and data groups of an ISO-compliant WBGT meter, inputting a real air temperature, an arbitrary-diameter globe temperature and a relative humidity under a real thermal environment; and obtaining a standard-diameter globe temperature and a natural wet-bulb temperature of the ISO-compliant WBGT meter, wherein each of the data groups of the electronic WBGT meter including an arbitrary-diameter globe temperature of the electronic WBGT meter, an air temperature, and a relative humidity obtained in respect with each of specific thermal environments based on air temperatures, average radiation temperatures, and wind velocities under the specific thermal environments; and each of the data groups of the ISO-compliant WBGT meter including a standard-diameter globe temperature of the ISO-compliant WBGT meter obtained with respect to each of the specific thermal environments based on the air temperatures, the average radiation temperatures and the wind velocities under the specific thermal environments, and a natural wet-bulb temperature obtained with respect to each of the specific thermal environments based on the air temperatures, the average radiation temperatures, the wind velocities, and relative humidities under the specific thermal environments; and a WBGT calculation unit for calculating an WBGT index based on the standard-diameter globe temperature, the natural wet-bulb temperature, and the air temperature outputted from the measurement calculation element.

35. The electronic WBGT meter according to claim 34, comprising, a correlation determination unit determines the correlation by learning the input and output data groups or a correlation determination unit determines the correlation by obtaining an approximate equation that is completed between the input and output data groups.

36. A measurement calculation element that stores a correlation between data groups of an electronic WBGT meter and data groups of an ISO-compliant WBGT meter, inputs a real air temperature, an arbitrary-diameter globe temperature and a relative humidity under a real thermal environment, and obtains a standard-diameter globe temperature and a natural wet-bulb temperature of the ISO-compliant WBGT meter, wherein each of the data groups of the electronic WBGT meter including an arbitrary-diameter globe temperature of the electronic WBGT meter, an air temperature, and a relative humidity obtained in respect with each of the specific thermal environments based on air temperatures, average radiation temperatures, and wind velocities under the specific thermal environments, and each of the data groups of the ISO-compliant WBGT meter including a standard-diameter globe temperature of the ISO-compliant WBGT meter obtained with respect to each of the specific thermal environments based on the air temperatures, the average radiation temperatures and the wind velocities under the specific thermal environments, and a natural wet-bulb temperature obtained with respect to each of the specific thermal environments based on the air temperatures, the average radiation temperatures, the wind velocities, and relative humidities under the specific thermal environments.

37. The measurement calculation element according to claim 36, wherein the correlation is determined by learning the data group of the electronic WBGT meter and the data group of the ISO-compliant WBGT meter or wherein the correlation is determined by obtaining an approximate equation that is completed between the input and output data groups.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0024] FIG. 1 is a schematic view showing an outline of the present invention; and,

[0025] FIG. 2 is a block diagram of the present invention.

DESCRIPTION OF EMBODIMENTS

<Principle>

[0026] FIG. 1 is a diagram showing a basic concept of the present invention. An arbitrary-diameter globe temperature tg? indicated by the electronic WBGT meter 2 under a specific thermal environment 1 (an air temperature ta, an average radiation temperature tr, a wind velocity v, a relative humidity rh) can be calculated by Equation (2). A standard-diameter globe temperature tgSTD indicated by an ISO-compliant WBGT meter 3 under the same specific thermal environment 1 can be calculated by Equation (3). Further, a natural wet-bulb temperature tw indicated by an ISO-compliant WBGT meter 3 under the same specific thermal environment 1 can be calculated by Equations (4) and (5). Therefore, it is possible to make one-to-one correspondence between an output of the electronic WBGT meter 2 (the air temperature ta, the arbitrary-diameter globe temperature tg?, the relative humidity rh) and an output of the ISO-compliant WBGT meter 3 (the air temperature ta, the standard-diameter globe temperature tgSTD, the natural wet-bulb temperature tw), so that by obtaining the mutual correlation between them, the output of the ISO-compliant WBGT meter 3 can be obtained based on the output of the electronic WBGT meter 2.

[0027] According to Annex B in ISO7726, it is possible to calculate the average radiation temperature under the forced convection from the globe temperature by a following equation (1).

[00001]$\begin{array}{cc}tr={\left[{\left(tg+273\right)}^4+\frac{1.1\times 10^8\times v^{0.6}}{\epsilon \times D^{0.4}}\left(\mathrm{tg}-\mathrm{ta}\right)\right]}^{1/4}-273& \left(1\right)\end{array}$

[0028] In the equation (1), D is a diameter of the standard-diameter globe, and tg is a temperature of the standard-diameter globe (hereinafter referred to as tgSTD). Moreover, the above equation can be applied to an arbitrary-diameter d of the arbitrary-diameter globe, and can be converted to a following equation (2) as the thermal equilibrium equation. The thermal equilibrium equation for the standard-diameter globe is a following equation (3).

1.1×10.sup.8×v.sup.0.6(tg?−ta)−εd.sup.0.4(Tr.sup.4−Tg?.sup.4)=0  (2)

1.1×10.sup.8×v.sup.0.6(tgSTD−ta)−ε(0.15).sup.0.4(Tr.sup.4−TgSTD.sup.4)=0  (3)

[0029] Where the air temperature ta, the average radiation temperature tr(Tr=tr+273), the wind velocity v, the globe diameter d, and the globe emissivity ε (e.g. ε=0.90) under the specific thermal environment are substituted in the equation (2), the arbitrary-diameter globe temperature tg? can be calculated. That is to say, the arbitrary-diameter globe temperature tg?(Tg?=tg?+273) can be obtained based on the air temperature ta, the average radiation temperature tr(Tr), and the wind velocity v under the specific thermal environment.

[0030] Where the air temperature ta, the average radiation temperature tr(Tr), the wind velocity v, the globe diameter D (=0.15), and the standard-diameter globe emissivity (ε=0.95) under the specific thermal environment are substituted in the equation (3), the standard-diameter globe temperature tgSTD(Tg=tgSTD+273) can be calculated. That is to say, the standard-diameter globe temperature tgSTD(TgSTD) can be obtained based on the air temperature ta, the average radiation temperature tr(Tr), and the wind velocity v under the specific thermal environment.

[0031] The thermal equilibrium equation for the natural wet-bulb temperature is a following equation (4) (ISO 7243, Annex D).

4.18v.sup.0.444(Ta−Tw)+10.sup.8(Tr.sup.4−Tw.sup.4)−77.1v.sup.0.421[Pa(tw)−rh×Pa(ta)]=0  (4)

[0032] Here, a saturated vapor pressure Pa(t) at a specific temperature (t) is calculated by a following equation (5) on the basis of Tetens Equation.

[00002]$\begin{array}{cc}Pa\left(P\right)=6.1078\times {10}^{\frac{7.5t}{t+237.3}}& \left(5\right)\end{array}$

[0033] Where the air temperature ta(Ta), the average radiation temperature tr(Tr), the wind velocity v, the saturated vapor pressure Pa(ta) at the air temperature ta, and a relative humidity rh, those under the specific thermal environment, are substituted in the above equation, the natural wet-bulb temperature tw(Tw) of the ISO-compliant WBGT meter can be obtained.

[0034] According to the above process, it is possible to obtain the standard-diameter globe temperature tgSTD(TgSTD) and the natural wet-bulb temperature tw(Tw) corresponding to the ISO-compliant WBGT meter that reflect the wind velocity and the average radiation temperature under the same specific thermal environment, and correspond in one-to-one to the arbitrary-diameter globe temperature tg?(Tg?) of the electronic WBGT meter. The equations (10) and (11) are calculated based on the values obtained in such way, so that it is possible to obtain an WBGT index reflecting the wind velocity and the average radiation temperature based on the output of the electronic WBGT meter.

<Creation and Learning of Data>

[0035] FIG. 2 is a block diagram of the present invention.

[0036] Where, according to the above process, the air temperature ta, the standard-diameter globe temperature tgSTD(TgSTD) and the natural wet-bulb temperature tw(Tw) of the ISO-compliant WBGT meter are obtained in advance, with respect to each of the specific thermal environments, together with the air temperature to and the relative humidity rh, that corresponds in one-to-one to the arbitrary-diameter globe temperature tg?(Tg?) of the electronic WBGT meter, those obtained values are available to the learning of a neural network (correlation determination unit 14) as described hereinafter.

[0037] First of all, in a first calculation unit 11, the air temperature ta, the wind velocity v, the globe emissivity e, the arbitrary globe diameter d, and the average radiation temperature Tr with respect to each of the thermal environments are substituted in the equation (2), so that the globe temperature tg? of the diameter d is obtained in advance.

[0038] Next, in a second calculation unit 12, the air temperature ta, the wind velocity v, the globe emissivity ε(=0.95), the standard globe diameter D(=0.15), and the average radiation temperature Tr with respect to each of the specific thermal environments are substituted into the equation (3), so that the standard-diameter globe temperature tgSTD is obtained in advance.

[0039] Here, since the equation (2) and the equation (3) are quartic equations of tg? or tgSTD, those values can be numerically obtained by Newton's Method.

[0040] Further, in a third calculation unit 13, the air temperature ta(Ta), the average radiation temperature Tr, the wind velocity v, the relative humidity rh, and the saturated vapor pressure Pa(ta) at the air temperature ta with respect to each of the thermal environments are substituted into the equation (4), so that the natural wet-bulb temperature Tw(tw) is obtained together with the corresponding saturated vapor pressure Pa(tw).

[0041] In the equations (4) and (5), it is possible to obtain two unknowns Tw and Pa(tw) numerically at the same time by the Fales Position Method. Otherwise, the natural wet-bulb temperature Tw(tw) can be obtained by substituting the equation (5) into the equation (4) and using the Newton Method.

[0042] And then, the neural network (a correlation determination unit 14) learns training data, wherein the arbitrary-diameter globe temperature tg?, the air temperature ta, and the relative humidity rh under each thermal environment obtained as above are set as an input, while the standard-diameter globe temperature tgSTD and the natural wet-bulb temperature tw are set as an output.

[0043] The configuration (the process) before finding the correlation between the outputs and the inputs, namely, plural units (the first calculation unit 11, the second calculation unit 12, the third calculation unit 13, and the correlation determination unit 14), can be realized as a correlation device provided separately from the following electronic WBGT meter. That is to say, in the correlation device, the correlation decided as above is stored in a measurement calculation element 15, and the measurement calculation element 15 is mounted in the electronic WBGT meter, which is applied to the calculation of the ISO-compliant WBGT index as described hereinafter.

<The Electronic WBGT Meter>

[0044] Where the neural network learned as above is mounted in the electronic WBGT meter as the measurement calculation element 15, when the air temperature ta0, the arbitrary-diameter globe temperature tg?0, and the relative humidity rh0 under the real thermal environment are inputted therein, the standard-diameter globe temperature tgSTD and the natural wet-bulb temperature tw can be obtained in addition to the air temperature ta. Moreover, the standard-diameter globe temperature tgSTD and the natural wet-bulb temperature tw reflect the wind velocity and the average radiation temperature.

[0045] Besides, the measurement calculation element 15 is also provided with a function of the neural network, and learns based on the new data inputted therein, so that it is possible to improve the accuracy.

[0046] When the air temperature ta, the standard-diameter globe temperature tgSTD, and the natural wet-bulb temperature tw obtained as described above are inputted in a WBGT calculation unit 16, it is possible to obtain the WBGT index reflecting the wind velocity and the average radiation temperature, even though the electronic WBGT meter without the anemometer.

<Testing>

[0047] The training data under the thermal environment is created by following process.

TABLE-US-00001 TABLE 1 Number of Number Range Resolution divisions of data Temperature 16~32(° C.) 2(° C.) 8 9 ta Wind 0.12~3.12(m/s)    0.1(m/s)  30 31 velocity v Average 20~60(° C.) 4(° C.) 10 11 radiation temperature tr Relative 20~80(%).sup.  3(%).sup.  20 21 humidity rh

[0048] By multiplying the number of data in each of the above items, the total number of data is 64,449, of which 50,000 are set as leaning data and 14,449 are set as test data.

[0049] When estimating from the above 14,449 test data, using the neural network (the measurement calculation element 15) that has learned 50,000 data as the learning data, the result of the estimate errors is shown in following Table 2.

TABLE-US-00002 TABLE 2 ΔtgSTD Δtw ΔWBGT Number 14,449 14,449 14,449 Average 0.000 0.009 0.006 Standard deviation 0.232 0.317 0.228 Minimum −1.042 −2.015 −1.370 Maximum 1.487 1.092 0.888

[0050] According to the above results, it can be said that the WBGT index can be estimated in an error range of ±0.7° C. with a 99% probability under an arbitrary wind velocity.

[0051] Here, with respect to the above 14,449 data, the standard-diameter globe temperatures are calculated by the globe thermal equilibrium equation assuming the wind velocity from the arbitrary-diameter globe temperature tg?, and then, the natural wet-bulb temperatures tw are calculated based on the air temperature to and the relative humidity rh by the Ango equation. The estimate results of this conventional method is shown in below, Table 3.

TABLE-US-00003 TABLE 3 ΔtgSTD Δtw ΔWBGT Number 14,449 14,449 14,449 Average −0.292 −0.543 −0.467 Standard deviation 0.376 1.441 1.036 Minimum −1.079 −10.162 −6.583 Maximum 1.772 2.202 1.453

[0052] It is understood that, when the standard deviations of ΔWBGT obtained by the above conventional method are compared with the values of the method of the present invention, the error distribution has a spread of about 4.5 times of the present invention.

EXAMPLE

[0053] According to the above description, the standard-diameter globe temperature tgSTD, the natural wet-bulb temperature tw, and the WBGT index are estimated by inputting the air temperature ta, the globe temperature tg50, and the relative humidity rh indicated by the electronic WBGT meter with the 50 mm diameter globe. The estimate values are compared with the corresponding correct values, which are shown in Table 4. Accordingly, it can be understood that the electronic WBGT meter in accordance with the present invention can obtain WBGT indices that are sufficiently put into practical use.

TABLE-US-00004 TABLE 4 Unit ° C. Estimate_ Estimate_ Estimate_ Correct_ Correct_ Correct_ ta tg50 rh tgSTD tw WBGT tgSTD tw WBGT 26 31.246 38 33.340 18.647 23.055 33.378 18.431 22.915 28 29.045 53 29.475 21.423 23.838 29.515 21.176 23.677 30 32.747 50 33.838 22.807 26.117 33.949 22.805 26.148 32 32.000 44 31.998 22.090 25.063 32.000 22.441 25.309 24 27.385 23 28.750 13.784 18.274 28.561 13.964 18.343 16 19.571 44 21.051 11.078 14.070 21.153 11.298 14.254 24 25.801 44 26.546 17.233 20.027 26.589 16.721 19.682 26 29.714 50 31.206 20.402 23.643 30.796 20.116 23.320 18 29.554 29 33.070 13.583 19.429 32.906 14.082 19.729 20 27.980 71 31.042 19.271 22.803 31.276 19.245 22.854 22 24.996 56 26.224 17.552 20.153 26.176 17.354 20.000 20 23.515 26 24.951 11.661 15.648 24.999 11.707 15.695 22 29.404 80 32.315 21.916 25.036 32.479 21.818 25.016 26 34.533 68 37.364 24.288 28.211 37.293 23.941 27.947 26 29.378 53 30.738 20.758 23.752 30.860 20.290 23.461 30 33.215 74 34.496 26.744 29.069 34.563 26.955 29.238 30 30.472 41 30.664 20.313 23.418 30.648 20.536 23.569 32 28.789 71 27.526 26.050 26.493 27.674 26.867 27.109

<Curve Fitting>

[0054] The data obtained under a plurality of the specific thermal environments according to the above process, namely, the arbitrary-diameter globe temperature tg? calculated by the first calculation unit 11, the standard-diameter globe temperature tgSTD calculated by the second calculation unit 12, and the natural wet-bulb temperature tw calculated by the third calculation unit 13, can be used as the data for determining an approximate equation for the curve fitting together with the air temperature ta and the relative humidity rh.

[0055] In other words, a following approximate equation (6) is obtained by the correlation between the air temperature ta, the arbitrary-diameter globe temperature tg?, and the standard-diameter globe temperature tgSTD. And then, on the basis of the obtained data group of the air temperature ta, the arbitrary-diameter globe temperature tg?, and the standard-diameter globe temperature tgSTD, the correlation determination unit 14 can determine each coefficient of degrees. Besides, the equation is a quadratic equation of tg and tgSTD in this embodiment, however, the degree of the equation can be increased or decreased freely according to the required accuracy. In addition, the method of calculating each coefficient of degrees is well-known in public, and the explanation is not described here.

tgSTD=A.Math.ta.sup.2+B.Math.ta+C.Math.tg?.sup.2+D.Math.tg?+E.Math.ta.Math.tg?+Q  (6)

[0056] Here, if the arbitrary diameter is 50 mm (tg50), each coefficient is determined using the 50,000 data, and the results are as follows.

[0057] A=−0.00813305888, B=−0.567951826, C=−0.0137013277, D=1.59857015, E=0.0214477372, Q=−0.487003283

[0058] In addition, the natural wet-bulb temperature tw can be obtained by a following equation (7), on the basis of the air temperature ta, the arbitrary-diameter globe temperature tg?, and the relative humidity rh.

tw=A.Math.ta.sup.3+B.Math.ta.sup.2+C.Math.ta+D.Math.tg?.sup.3+E.Math.tg?.sup.2+F.Math.tg?+G.Math.rh.sup.3+H.Math.rh.sup.2+I.Math.rh+J.Math.ta.Math.tg?.Math.rh+K.Math.tg?.Math.rh+L.Math.ta.Math.rh+M.Math.ta.Math.tg?+Q  (7)

[0059] The correlation determination unit 14 can determine the each coefficient of degrees based on the data group of the air temperature ta, the arbitrary-diameter globe temperature tg?, the relative humidity rh, and the natural wet-bulb temperature tw, that are obtained as described above.

[0060] Here, where the arbitrary diameter is 50 mm (tg50), each coefficient is determined using the 50,000 data, and the results are as follows. In this case, it is configured to obtain the third-degree coefficient with respect to ta, tg, and rh, however, the degree of coefficient can be increased or decreased according to the conditions.

TABLE-US-00005 A = −5.01528377 × 10.sup.−5, B = 0.0108706541, C = −0.157896135, D = 0.000109347496, E = −0.0104562755, F = 0.889654587, G = 1.60312065 × 10.sup.−6, H = −0.00068305723, I = −0.105621516, J = 2.35596747 × 10.sup.−6, K = −0.00210613502, L = 0.00658788765, M = −0.00561414292, Q = −7.47427592

[0061] Where each coefficient of degree in the respective equations is determined in this way, the equations (6) and (7), of which the coefficients are determined, are stored in the measurement calculation element 15, whereby the standard-diameter globe temperature tgSTD, the natural wet-bulb temperature tw, and the air temperature to are obtained on the basis of the air temperature ta0, the relative humidity rh0, and the arbitrary-diameter globe temperature tg?0 under the real thermal environment, and the output of the ISO-compliant WBGT index is obtained by the WBGT calculation unit 16.

<Testing>

[0062] When estimating by the above two equations using 14,449 test data, the difference between the estimation and the above correct data with respect to the standard-diameter globe temperature tgSTD and the natural wet-bulb temperature tw is shown in Table 5.

TABLE-US-00006 TABLE 5 ΔtgSTD Δtw ΔWBGT Number 14,449 14,449 14,449 Average 0.000 −0.001 −0.001 Standard deviation 0.232 0.141 0.105 Minimum −1.501 −1.180 −1.162 Maximum 1.417 0.527 0.407

EXAMPLES

[0063] Table 6 shows the real air temperature ta, the globe temperature tg50, and the relative humidity rh, indicated by the electronic WBGT meter provided with the globe in 50 mm diameter; the standard-diameter globe temperature tgSTD, the natural wet-bulb temperature tw and the WBGT index that are obtained by inputting the above mentioned data into the above approximate equations; and the globe temperature tgSTD, the natural wet-bulb temperature tw, and the WBGT index indicated by the ISO-compliant WBGT meter. It is understood that it is possible to obtain values enough for practical use by the electronic WBGT meter.

TABLE-US-00007 TABLE 6 Unit ° C. Estimate_ Estimate_ Estimate_ correct_ correct_ correct_ ta tg50 rh tgSTD tw WBGT tgSTD tw WBGT 26 32.653 59 35.047 22.178 26.039 35.115 22.162 26.048 32 30.965 23 30.624 17.657 21.547 30.503 17.256 21.230 18 41.439 38 45.368 19.789 27.463 46.003 19.571 27.501 32 29.144 29 27.964 18.404 21.272 28.306 18.882 21.709 20 26.154 35 28.557 14.105 18.441 28.809 14.101 18.513 32 36.555 29 38.225 20.772 26.008 38.136 20.785 25.990 20 23.033 68 24.332 17.270 19.389 24.280 17.238 19.351 18 19.251 41 19.784 11.525 14.003 19.821 11.417 13.938 22 23.274 50 23.846 15.954 18.322 23.851 15.855 18.254 26 31.833 53 34.002 21.038 24.927 34.113 21.030 24.955 30 33.490 20 34.872 17.193 22.497 34.780 17.109 22.411 16 17.107 59 17.551 12.060 13.707 17.492 12.098 13.716 28 29.654 47 30.398 20.351 23.365 30.392 20.319 23.341 16 18.086 47 18.980 11.086 13.454 18.964 11.005 13.393 24 31.751 41 34.485 18.339 23.183 34.857 18.310 23.274 16 21.723 50 24.059 12.935 16.272 23.451 12.889 16.058 26 25.190 32 24.869 15.299 18.170 24.973 15.888 18.613 16 20.317 41 22.138 11.319 14.565 22.282 11.303 14.597

INDUSTRIAL APPLICABILITY

[0064] As described above, the present invention allows the electronic WBGT meter without the aerometer and the wet-bulb to obtain the standard-diameter globe temperature, the natural wet-bulb temperature, and the WBGT index, those reflecting the wind velocity and the average radiation temperature. The present invention is very available with respect to the cost and the device capacity.

[0065] Besides, the first to third calculation units, the correlation determination unit, the measurement calculation element, and the WBGT calculation unit can be realized by an electronic circuit or a program working with a computer. In addition, it is general that the electronic WBGT meter is delivered in a state of mounting the measurement calculation element therein, but it is possible to deal with the measurement calculation element as one unit. The user subscribed the unit mounts it on the electronic WBGT meter by the user.

REFERENCE SIGNS LIST

[0066] 1 Thermal environment [0067] 2 Electronic WBGT meter [0068] 3 ISO-compliant WBGT meter [0069] 11 First calculation unit [0070] 12 Second calculation unit [0071] 13 Third calculation unit [0072] 14 Correlation determination unit [0073] 15 Measurement calculation element [0074] 16 WBGT calculation unit [0075] ta: Temperature [° C.] (ta0: Real temperature) [0076] Ta: ta+273 (absolute temperature) [0077] v: Wind velocity [m/s] [0078] tg: Globe temperature [° C.] [0079] Tg: Globe absolute temperature (tg+273) [0080] tgSTD: Globe Temperature in 150 mm diameter [0081] tg?: Globe temperature in an arbitrary-diameter (tg?0: Real globe temperature in arbitrary-diameter) [0082] tr: Average radiation temperature [° C.] [0083] Tr: Absolute temperature of average radiation temperature (tr+273) [0084] tw: Natural wet-bulb temperature [0085] Tw: Natural wet-bulb absolute temperature (tw+273) [0086] Pa(t): Saturated vapor pressure at temperature t [0087] rh: Relative humidity (rh0: Real relative humidity) [0088] d: Diameter of globe (arbitrary diameter) [0089] D: Diameter of standard globe (standard diameter=0.15 m) [0090] ε: Emissivity