griffin175:
I tried doing it the way which obviously wouldn't work, using floats.
Wrong.
The values below are T as 32 bit float, result calculated only using 32 bit float, T as 80 bit float, result calculated only using 80 bit float, the delta, and the percent error...
273.15 --> 606.1 273.15 --> 606.1 : 0.000045, 0.00
274.15 --> 651.6 274.15 --> 651.6 : -0.001105, -0.00
275.15 --> 700.1 275.15 --> 700.1 : -0.000062, -0.00
276.15 --> 751.7 276.15 --> 751.7 : -0.001972, -0.00
277.15 --> 806.7 277.15 --> 806.7 : -0.001487, -0.00
278.15 --> 865.2 278.15 --> 865.2 : -0.001495, -0.00
279.15 --> 927.4 279.15 --> 927.4 : -0.002474, -0.00
280.15 --> 993.5 280.15 --> 993.5 : -0.001317, -0.00
281.15 --> 1063.8 281.15 --> 1063.8 : -0.002043, -0.00
282.15 --> 1138.4 282.15 --> 1138.4 : -0.001426, -0.00
283.15 --> 1217.5 283.15 --> 1217.5 : -0.000308, -0.00
284.15 --> 1301.5 284.15 --> 1301.5 : 0.000709, 0.00
285.15 --> 1390.6 285.15 --> 1390.6 : -0.000218, -0.00
286.15 --> 1484.9 286.15 --> 1484.9 : 0.001201, 0.00
287.15 --> 1584.9 287.15 --> 1584.9 : -0.002508, -0.00
288.15 --> 1690.7 288.15 --> 1690.7 : -0.001714, -0.00
289.15 --> 1802.6 289.15 --> 1802.6 : 0.002052, 0.00
290.15 --> 1921.0 290.15 --> 1921.0 : 0.000072, 0.00
291.15 --> 2046.2 291.15 --> 2046.2 : 0.003112, 0.00
292.15 --> 2178.4 292.15 --> 2178.4 : 0.000971, 0.00
293.15 --> 2318.1 293.15 --> 2318.1 : -0.002909, -0.00
294.15 --> 2465.6 294.15 --> 2465.6 : -0.003076, -0.00
295.15 --> 2621.2 295.15 --> 2621.2 : -0.003475, -0.00
296.15 --> 2785.3 296.15 --> 2785.3 : 0.000832, 0.00
297.15 --> 2958.3 297.15 --> 2958.3 : -0.006042, -0.00
298.15 --> 3140.6 298.15 --> 3140.6 : 0.003490, 0.00
299.15 --> 3332.7 299.15 --> 3332.7 : -0.000254, -0.00
300.15 --> 3534.9 300.15 --> 3534.9 : -0.000128, -0.00
301.15 --> 3747.7 301.15 --> 3747.7 : -0.004088, -0.00
302.15 --> 3971.5 302.15 --> 3971.5 : -0.006765, -0.00
303.15 --> 4206.9 303.15 --> 4206.9 : -0.002310, -0.00
304.15 --> 4454.4 304.15 --> 4454.4 : 0.000328, 0.00
305.15 --> 4714.4 305.15 --> 4714.4 : 0.006549, 0.00
306.15 --> 4987.5 306.15 --> 4987.5 : -0.014816, -0.00
307.15 --> 5274.2 307.15 --> 5274.2 : -0.002746, -0.00
308.15 --> 5575.0 308.15 --> 5575.0 : -0.007781, -0.00
309.15 --> 5890.7 309.15 --> 5890.7 : -0.006126, -0.00
310.15 --> 6221.7 310.15 --> 6221.6 : -0.013564, -0.00
311.15 --> 6568.6 311.15 --> 6568.6 : 0.000348, 0.00
312.15 --> 6932.2 312.15 --> 6932.2 : -0.008471, -0.00
313.15 --> 7313.0 313.15 --> 7313.0 : -0.010323, -0.00
314.15 --> 7711.7 314.15 --> 7711.7 : 0.001449, 0.00
315.15 --> 8129.1 315.15 --> 8129.1 : 0.004461, 0.00
316.15 --> 8565.8 316.15 --> 8565.8 : -0.000115, -0.00
317.15 --> 9022.6 317.15 --> 9022.6 : -0.005756, -0.00
318.15 --> 9500.2 318.15 --> 9500.2 : -0.008059, -0.00
319.15 --> 9999.4 319.15 --> 9999.4 : -0.002437, -0.00
320.15 --> 10521.1 320.15 --> 10521.0 : -0.025278, -0.00
321.15 --> 11065.9 321.15 --> 11065.9 : 0.009482, 0.00
322.15 --> 11634.8 322.15 --> 11634.7 : -0.021328, -0.00
323.15 --> 12228.5 323.15 --> 12228.5 : 0.019953, 0.00
324.15 --> 12848.1 324.15 --> 12848.1 : -0.005929, -0.00
325.15 --> 13494.4 325.15 --> 13494.4 : -0.002115, -0.00
326.15 --> 14168.4 326.15 --> 14168.4 : -0.015175, -0.00
327.15 --> 14870.9 327.15 --> 14870.9 : 0.006430, 0.00
328.15 --> 15603.1 328.15 --> 15603.1 : -0.048064, -0.00
329.15 --> 16365.8 329.15 --> 16365.8 : -0.006084, -0.00
330.15 --> 17160.2 330.15 --> 17160.1 : -0.049091, -0.00
331.15 --> 17987.2 331.15 --> 17987.2 : 0.013323, 0.00
332.15 --> 18848.0 332.15 --> 18848.0 : -0.022845, -0.00
333.15 --> 19743.6 333.15 --> 19743.6 : -0.025227, -0.00
334.15 --> 20675.2 334.15 --> 20675.2 : 0.002565, 0.00
335.15 --> 21644.1 335.15 --> 21644.0 : -0.022104, -0.00
336.15 --> 22651.2 336.15 --> 22651.2 : -0.026226, -0.00
337.15 --> 23697.9 337.15 --> 23697.9 : -0.021074, -0.00
338.15 --> 24785.4 338.15 --> 24785.4 : -0.012074, -0.00
339.15 --> 25915.0 339.15 --> 25914.9 : -0.012179, -0.00
340.15 --> 27087.9 340.15 --> 27087.9 : -0.037680, -0.00
341.15 --> 28305.5 341.15 --> 28305.5 : 0.001448, 0.00
342.15 --> 29569.1 342.15 --> 29569.1 : -0.014579, -0.00
343.15 --> 30880.2 343.15 --> 30880.2 : 0.000928, 0.00
344.15 --> 32240.2 344.15 --> 32240.1 : -0.090239, -0.00
345.15 --> 33650.3 345.15 --> 33650.2 : -0.068894, -0.00
346.15 --> 35112.2 346.15 --> 35112.2 : -0.078906, -0.00
347.15 --> 36627.3 347.15 --> 36627.3 : -0.013663, -0.00
348.15 --> 38197.3 348.15 --> 38197.2 : -0.043175, -0.00
349.15 --> 39823.5 349.15 --> 39823.5 : -0.049378, -0.00
350.15 --> 41507.7 350.15 --> 41507.6 : -0.082932, -0.00
351.15 --> 43251.3 351.15 --> 43251.3 : -0.011434, -0.00
352.15 --> 45056.3 352.15 --> 45056.2 : -0.038721, -0.00
353.15 --> 46924.0 353.15 --> 46924.0 : -0.044504, -0.00
354.15 --> 48856.4 354.15 --> 48856.3 : -0.072436, -0.00
355.15 --> 50855.0 355.15 --> 50855.0 : 0.009934, 0.00
356.15 --> 52921.8 356.15 --> 52921.8 : -0.031608, -0.00
357.15 --> 55058.6 357.15 --> 55058.5 : -0.075099, -0.00
358.15 --> 57267.2 358.15 --> 57267.0 : -0.169554, -0.00
359.15 --> 59549.1 359.15 --> 59549.1 : 0.043335, 0.00
360.15 --> 61906.9 360.15 --> 61906.8 : -0.170628, -0.00
361.15 --> 64341.9 361.15 --> 64341.9 : 0.045611, 0.00
362.15 --> 66856.6 362.15 --> 66856.5 : -0.117294, -0.00
363.15 --> 69452.5 363.15 --> 69452.5 : 0.013494, 0.00
364.15 --> 72132.0 364.15 --> 72132.1 : 0.093146, 0.00
365.15 --> 74897.2 365.15 --> 74897.2 : 0.021015, 0.00
366.15 --> 77750.0 366.15 --> 77750.0 : -0.020166, -0.00
367.15 --> 80692.7 367.15 --> 80692.5 : -0.157914, -0.00
368.15 --> 83727.3 368.15 --> 83727.1 : -0.189253, -0.00
369.15 --> 86856.1 369.15 --> 86855.9 : -0.229045, -0.00
370.15 --> 90081.1 370.15 --> 90081.1 : -0.077075, -0.00
371.15 --> 93405.1 371.15 --> 93404.9 : -0.186705, -0.00
372.15 --> 96829.8 372.15 --> 96829.8 : -0.008539, -0.00
373.15 --> 100358.1 373.15 --> 100358.1 : -0.045029, -0.00