Looking at AN-1087, Table 3 - The AD8495 should be reporting the following mV values for a K type thermocouple at these temps.

TempC, OutputV

0, 0.003

20, 0.100

40, 0.200

60, 0.301

80, 0.402

100, 0.504

120, 0.605

140, 0.705

160, 0.803

180, 0.901

200, 0.999

220, 1.097

Based on the 6th order calc's, using the data found here

a0 = 1.1465785E+00, a1 = 4.83944867E+00, a2 = 2.1522617E-03, a3 = 1.2971024E-05, a4 = -2.7040225E-07, a5 = 1.152638E-09, a6 = -1.5282588E-12

Vout(mV) = a0 + a1*T + a2*T^2 + a3*T^3 + a4*T^4 + a5*T^5 + a6*T^6 where T is the measurement temperature

The expected results are:

TempC, OutputV

0, 0.0011465785

20, 0.098860551045

40, 0.198417830179

60, 0.29938395771

80, 0.401018775432

100, 0.5025429827

120, 0.603334271849

140, 0.703053041435

160, 0.801697687321

180, 0.899589471591

200, 0.9972869693

220, 1.09543009306

Any reason Table 3 doesn't match up with these values?

Hi Steve,

The equation that you used is a 6th order polynomial fit of the data from the table in AN-1087. That fit is not perfect, so that is why you are seeing the error between the output from the equation and the data in the table.

Hope that helps!

Regards,

Jordyn