The second form of the equation emphasizes the most efficient order of operations. The function uses a ratio of two polynomials, P/Q, in this case a fourth order to a third order polynomial. Where T is the thermocouple temperature (in ☌), V is the thermocouple voltage (in millivolts), and T o, V o, and the p i and q i are coefficients.
![temperature conversion formula excel temperature conversion formula excel](https://db-excel.com/wp-content/uploads/2019/09/temperature-conversion-worksheet-4.png)
Using a least squares curve fitting procedure we fit the National Institute of Standards and Technology (NIST) type K thermocouple data with a rational function of the following form, The calibration equation uses a ratio of two smaller order polynomials rather than one large order polynomial. This page shows you how to convert type K thermocouple voltage to temperature with rational polynomial functions accurately and efficiently – more so than you can using NIST's higher order polynomials.Ī rational polynomial function approximation for Type K thermocouples is used for computing temperature from measured thermocouple potential. However, the polynomial equations NIST provides aren't as accurate as they should be – they produce errors of fit as the high-order polynomial functions oscillate around the data, as shown in these curve fits of NIST polynomials to Type K thermocouple data.įortunately, there are more accurate ways to fit the data – using rational polynomial functions. NIST, the National Institute of Standards and Technology, provides a database of thermocouple values and a high order polynomial formula curve fitted to type K thermocouple data.
![temperature conversion formula excel temperature conversion formula excel](https://i.ytimg.com/vi/XQhc2orldGg/maxresdefault.jpg)
However, if you are not using the Mosaic Thermocouple Wildcard, but looking for accurate equations for type K thermocouple measurement, we hope the type K thermocouple calibration coefficients and methods here are helpful.Įquations for voltage to temperature conversion usually use high order polynomials. Mosaic's Thermocouple Wildcard automatically converts measured voltages to temperatures for you, and with high accuracy.