Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
MELTING POINT – SMP40 Technical note: T07-001A SMP40 Calibration – The SMP40’s Calibration Calculations Introduction To ensure the accuracy of its melting point data the SMP40 automatic melting point apparatus allows users to perform a single or dual point instrument calibration with suitable, certified melting point standards. This technical note discusses the calculations and process that are used by the SMP40 to generate accurate and reliable melting point data. SMP40 Calibration The SMP40’s displayed temperature value is calculated using the instrument’s platinum resistance temperature sensor data and the current calibration equation. Displayed Block Temperature = ax2 + bx + c (where x = Instrument’s PRT Temperature Value) When a new calibration procedure is performed the instrument requires the original PRT temperature values in order to accurately calibrate the instrument and calculate the values of a, b and c in the calibration equation. This is done by performing a quadratic regression through zero on a graph of the expected melting point values verses the original PRT temperature values. The instrument reports the calculated b term as the Calculated Calibration Factor and as the regression curve is forced through zero, the c term in the instrument’s calibration equation will always equal zero. Figure 1: Calibration Data Entry Screen The original PRT temperature values are calculated from the measured melting point data using a modified form of the standard quadratic formula:- PRT Temperature Value = -b + b2 + 4a(y) 2a where a and b are taken from the SMP40’s current calibration equation and (y) equals the measured melting point of the certified melting point standard. [email protected] +44 (0)1785 810433