Experimental Calibration Curves Research Articles

The application of the capacitance method for void fraction measurement in bulk boiling conditions

In this article the application of the impedance method, developed as capacitive, to the study of bulk boiling at atmospheric pressure, is described. Corresponding to two values of mass flowrate, the calibration curves void fraction vs. relative capacitance are deduced, up to void fractions of about 85–90 per cent: as a void fraction standard value the response of the dilatometric method is chosen. Finally the differences between the experimental calibration curves and the Maxwell law are calculated and plotted.

Age determination by study of the thermoluminescence of smoky quartz

The age of radioactive mineralization (Singhbhum district, Bhalki, India) has been determined on the basis of thermoluminescence of smoky quartz crystals collected from nonradioactive intrusive layers adjacent to radioactive veins. The ‘age equation’ has been derived by considering the absorption coefficient and the average energy of 7 rays reaching the quartz crystals. The total dosage received by smoky quartz crystals under field conditions has been computed from an experimental calibration curve of dosage versus thermoluminescence intensity. The value of age thus obtained is 940±160 m.y., which is in fair agreement with the values estimated from geological evidence.

Hot Thermistor Anemometer for Finite Amplitude Stability Measurements

A device similar to a hot wire anemometer has been developed in which the wire is replaced with a thermistor. Niiler has presented a theory of the response of the anemometer to velocity gradients. Experimental calibration curves are presented here to show that Niiler's model explains the operational characteristics quite satisfactorily. The associated electronic circuitry is described and the design considerations which determine the magnitudes of the various adjustable parameters are discussed. This anemometer has been used to detect the onset of the various modes of secondary flow, the amplitude of the disturbances, their wavelengths, and their drift velocities. Both velocity and temperature fields may be measured.