MEASUREMENT OF 0-1 ML VOLUMES USING THE PROCEDURE OF CAPACITIVE-DEPENDENT CRYSTALS

This paper analyses the differential quartz-oscillator method, which i s based on the small frequency shift of two oscillators. This frequenc y shift is achieved by changing the probe capacitance in the range bel ow 1 pF, which is the area of application of this method. It comprises drift compensation due to the temperature and voltage changes. By the aid of the direct digital method, which reduces the influence of dist urbances, the uncertainty of the measurement results is improved. Seve ral experiments have been carried out to investigate its possible appl ications. The experimental results of the measurement of 0-1 ml volume s are given. The method is linear in this range. It ensures an error b elow 0.01% and the volume measurement inaccuracy (0-1 ml) is less,than 0.05% (T=15-25 degrees C).