The following table of Student's "t" may be utilized for the calculation of various satistical significance, including detection limits and analytical sensitivity calculations. Here "#pts" is the number of measurements, "df" is the corresponding degrees of freedom, and the numerical headings indicate the confidence levels from 0.60 (60%) to 0.99 (99%).
#pts df 0.60 0.80 0.90 0.95 0.99
02 01 1.3764 3.0777 6.3138 12.7062 63.6567 03 02 1.0607 1.8856 2.9200 4.3027 9.9248 04 03 .9785 1.6377 2.3534 3.1824 5.8409 05 04 .9410 1.5332 2.1318 2.7764 4.6041 06 05 .9195 1.4759 2.0151 2.5706 4.0321 07 06 .9057 1.4398 1.9432 2.4469 3.7074 08 07 .8961 1.4149 1.8946 2.3646 3.4995 09 08 .8889 1.3968 1.8595 2.3061 3.3554 10 09 .8834 1.3831 1.8331 2.2622 3.2498 11 10 .8791 1.3722 1.8125 2.2281 3.1693 12 11 .8755 1.3634 1.7959 2.2010 3.1058 13 12 .8726 1.3562 1.7823 2.1788 3.0545 14 13 .8702 1.3502 1.7709 2.1604 3.0123 15 14 .8681 1.3451 1.7613 2.1448 2.9768 16 15 .8662 1.3406 1.7531 2.1314 2.9467 17 16 .8647 1.3368 1.7459 2.1199 2.9208 18 17 .8633 1.3334 1.7396 2.1098 2.8982 19 18 .8621 1.3304 1.7341 2.1009 2.8784 20 19 .8610 1.3277 1.7291 2.0931 2.8609 21 20 .8600 1.3253 1.7247 2.0860 2.8453 22 21 .8591 1.3232 1.7207 2.0796 2.8314 23 22 .8583 1.3212 1.7171 2.0739 2.8188 24 23 .8575 1.3195 1.7139 2.0687 2.8073 25 24 .8569 1.3178 1.7109 2.0639 2.7969 26 25 .8562 1.3163 1.7081 2.0595 2.7874 27 26 .8557 1.3150 1.7056 2.0555 2.7787 28 27 .8551 1.3137 1.7033 2.0518 2.7707 29 28 .8546 1.3125 1.7011 2.0484 2.7633 30 29 .8542 1.3114 1.6991 2.0452 2.7564 31 30 .8538 1.3104 1.6973 2.0423 2.7500 32 31 .8534 1.3095 1.6955 2.0395 2.7441 33 32 .8530 1.3086 1.6939 2.0369 2.7385 34 33 .8526 1.3077 1.6924 2.0345 2.7333 35 34 .8523 1.3069 1.6909 2.0322 2.7284 36 35 .8521 1.3062 1.6896 2.0301 2.7238 37 36 .8517 1.3055 1.6883 2.0281 2.7195 38 37 .8514 1.3049 1.6871 2.0262 2.7154 39 38 .8512 1.3042 1.6860 2.0244 2.7116 40 39 .8509 1.3036 1.6849 2.0227 2.7079 41 40 .8507 1.3031 1.6839 2.0211 2.7045 42 41 .8505 1.3025 1.6829 2.0195 2.7012 43 42 .8503 1.3021 1.6820 2.0181 2.6981 44 43 .8501 1.3016 1.6811 2.0167 2.6951 45 44 .8499 1.3011 1.6802 2.0154 2.6923 46 45 .8497 1.3007 1.6794 2.0141 2.6896 47 46 .8495 1.3002 1.6787 2.0129 2.6871 48 47 .8493 1.2998 1.6779 2.0117 2.6846 49 48 .8492 1.2994 1.6772 2.0106 2.6822 50 49 .8491 1.2991 1.6766 2.0096 2.6800