CONVERSION OF TEMPERATURES FROM THE 1948 AND 1968 SCALES TO ITS-90 This table gives temperature corrections from older scales to the current International Temperature Scale of 1990 (see the preceding table for details on ITS-90) The first part of the table may be used for converting Celsius temperatures in the range -180 to 4000°C from IPTS-68 or IPTS-48 to ITS90 Within the accuracy of the corrections, the temperature in the first column may be identified with either t68, t48, or t90 The second part of the table is designed for use at lower temperatures to convert values expressed in kelvins from EPT-76 or IPTS-68 to ITS-90 The references give analytical equations for expressing these relations Note that Reference supersedes Reference with respect to corrections in the 630 to 1064°C range REFERENCES Burns, G W et al., in Temperature: Its Measurement and Control in Science and Industry, Vol 6, Schooley, J F., Ed., American Institute of Physics, New York, 1993 Goldberg, R N and Weir, R D., Pure and Appl Chem., 1545, 1992 t/°C t90-t68 t90-t48 t/°C t90-t68 t90-t48 t/°C t90-t68 t90-t48 -180 -170 -160 -150 -140 -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 0.008 0.010 0.012 0.013 0.014 0.014 0.014 0.013 0.013 0.012 0.012 0.011 0.010 0.009 0.008 0.006 0.004 0.002 0.000 -0.002 -0.005 -0.007 -0.010 -0.013 -0.016 -0.018 -0.021 -0.024 -0.026 -0.028 -0.030 -0.032 -0.034 -0.036 -0.037 -0.038 -0.039 -0.039 -0.040 -0.040 -0.040 -0.040 -0.040 -0.040 -0.040 0.020 0.017 0.007 0.000 0.001 0.008 0.017 0.026 0.035 0.041 0.045 0.045 0.042 0.038 0.032 0.024 0.016 0.008 0.000 -0.006 -0.012 -0.016 -0.020 -0.023 -0.026 -0.026 -0.027 -0.027 -0.026 -0.024 -0.023 -0.020 -0.018 -0.016 -0.012 -0.009 -0.005 -0.001 0.003 0.007 0.011 0.014 0.018 0.021 0.024 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460 470 480 490 500 510 520 530 540 550 560 570 580 590 600 610 620 630 640 650 660 670 680 690 700 710 -0.039 -0.039 -0.039 -0.039 -0.039 -0.039 -0.040 -0.040 -0.041 -0.042 -0.043 -0.045 -0.046 -0.048 -0.051 -0.053 -0.056 -0.059 -0.062 -0.065 -0.068 -0.072 -0.075 -0.079 -0.083 -0.087 -0.090 -0.094 -0.098 -0.101 -0.105 -0.108 -0.112 -0.115 -0.118 -0.122 -0.125 -0.11 -0.10 -0.09 -0.07 -0.05 -0.04 -0.02 -0.01 0.028 0.030 0.032 0.034 0.035 0.036 0.036 0.037 0.036 0.035 0.034 0.032 0.030 0.028 0.024 0.022 0.019 0.015 0.012 0.009 0.007 0.004 0.002 0.000 -0.001 -0.002 -0.001 0.000 0.002 0.007 0.011 0.018 0.025 0.035 0.047 0.060 0.075 0.12 0.15 0.19 0.24 0.29 0.32 0.37 0.41 720 730 740 750 760 770 780 790 800 810 820 830 840 850 860 870 880 890 900 910 920 930 940 950 960 970 980 990 1000 1010 1020 1030 1040 1050 1060 1070 1080 1090 1100 1200 1300 1400 1500 1600 1700 0.00 0.02 0.03 0.03 0.04 0.05 0.05 0.05 0.05 0.05 0.04 0.04 0.03 0.02 0.01 0.00 -0.02 -0.03 -0.05 -0.06 -0.08 -0.10 -0.11 -0.13 -0.15 -0.16 -0.18 -0.19 -0.20 -0.22 -0.23 -0.23 -0.24 -0.25 -0.25 -0.25 -0.26 -0.26 -0.26 -0.30 -0.35 -0.39 -0.44 -0.49 -0.54 0.45 0.49 0.53 0.56 0.60 0.63 0.66 0.69 0.72 0.75 0.76 0.79 0.81 0.83 0.85 0.87 0.87 0.89 0.90 0.92 0.93 0.94 0.96 0.97 0.97 0.99 1.00 1.02 1.04 1.05 1.07 1.10 1.12 1.14 1.17 1.19 1.20 1.20 1.2 1.4 1.5 1.6 1.8 1.9 2.1 1-17 CONVERSION OF TEMPERATURES FROM THE 1948 AND 1968 SCALES TO ITS-90 (continued) t/°C t90-t68 t90-t48 T/K 1800 1900 2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000 -0.60 -0.66 -0.72 -0.79 -0.85 -0.93 -1.00 -1.07 -1.15 -1.24 -1.32 -1.41 -1.50 -1.59 -1.69 -1.78 -1.89 -1.99 -2.10 -2.21 -2.32 -2.43 -2.55 2.2 2.3 2.5 2.7 2.9 3.1 3.2 3.4 3.7 3.8 4.0 4.2 4.4 4.6 4.8 5.1 5.3 5.5 5.8 6.0 6.3 6.6 6.8 T/K T90-T76 T90-T68 -0.0001 -0.0002 -0.0003 -0.0004 -0.0005 -0.0006 -0.0007 -0.0008 -0.0010 -0.0011 -0.0013 -0.0014 -0.0016 -0.0018 -0.0020 -0.0022 -0.0025 -0.0027 -0.0030 -0.0032 -0.0035 -0.0038 -0.0041 -0.006 -0.003 -0.004 -0.006 -0.008 -0.009 -0.009 -0.008 -0.007 -0.007 -0.006 -0.005 -0.004 -0.004 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 T90-T76 1-18 T90-T68 T/K -0.005 -0.006 -0.006 -0.007 -0.008 -0.008 -0.008 -0.007 -0.007 -0.007 -0.006 -0.006 -0.006 -0.006 -0.006 -0.006 -0.006 -0.007 -0.007 -0.007 -0.006 -0.006 -0.006 -0.005 -0.005 -0.004 -0.003 -0.002 -0.001 0.000 0.001 0.002 0.003 0.003 0.004 0.004 0.005 0.005 0.006 0.006 0.007 0.007 0.007 0.007 0.007 0.007 0.007 0.008 0.008 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 273.16 300 400 500 600 700 800 900 T90-T76 T90-T68 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.009 0.009 0.009 0.009 0.011 0.013 0.014 0.014 0.014 0.014 0.013 0.012 0.012 0.011 0.010 0.009 0.008 0.007 0.005 0.003 0.001 0.000 -0.006 -0.031 -0.040 -0.040 -0.055 -0.089 -0.124