Development and Investigation of an Automated Temperature Calibration for Temperature Phosphors

Abstract: This thesis achieves a semi-automatic temperature calibration for thermographic phosphors. Thermocouple temperature information and phosphorescence decay curves are recorded synchronized and continuously while the oven temperature is ramped across the entire temperature range. A LabVIEW interface was developed in this context and applied to calibrate two phosphors, CdWO4 and Mg4FGeO6:Mn. These two thermographic phosphors have different temperature sensitive ranges, 294 K to 573 K for CdWO4 phosphor, and 294 K to 973 K for Mg4FGeO6:Mn phosphor. The conventional and automatic calibrations of CdWO4 have been performed using the same experimental setup. Though in this thesis work only on automatic calibration of Mg4FGeO6:Mn has been done, the conventional calibration presented in the article[1] was done under similar experimental condition. The automated results were compared to conventional calibrations showed no major difference neither for CdWO4 nor Mg4FGeO6:Mn. Additionally, this thesis studies some factors which may affect the accuracy of CdWO4 phosphor automatic calibration result. These factors include the relation between the phosphor response speed and thermocouple response speed, long exposure time for phosphor in high temperature environment, and laser induced heating effects. None of these factors showed a significant impact upon the obtained results within the area of investigation.