Calibration of the R ruby fluorescence lines in the pressure range [0-1 GPa] and the temperature range [250-300K]

The pressure range [0-1 GPa] and the temperature range [250 300K] are commonly used in many science fields like biology, agro-chemistry, pharmacology, or geology. In this paper, the calibration of the ruby R lines of fluorescence is performed in these pressure and temperature ranges, using the melting curve of pure water. The linear shifts of ruby peaks are equal to -0.140cm(-1)/K and -0.768cm(-1)/kbar with R-1, and to -0.137cm(-1)/K and -0.779cm(-1)/kbar with R-2. The accuracy of pressure measurements can be as good as +/-10MPa if the temperature is known with +/-0.5K. Such a precision is achieved if (1) the position of each peak is determined using an inversion method; (2) daily shifts of the spectrometer are corrected before each acquisition; (3) peak positions of each ruby are known at ambient pressure and temperature.