Abstract: The rubidium (Rb) spectral lamp is the critical component of Rb gas cell atomic frequency standard．As a measuring tool and research method the differential scanning calorimetry technique was indispensable in the manufacture of rubidium spectral lamp. Through fitting the rubidium consumption data obtained by Long-term tracing measurement, the consumption model of a rubidium spectral lamp used currently was established. The analysis result shows that the reactive loss of Rb consume about 37.5μg metal rubidium, The speed of rubidium consumption maintain constant at 0.23 microgram per square root of hour. The predicted total rubidium consumption in the ten years lifetime is about 106μg. The measurment result of melting point and purity of rubidium in lamp show that in the first two months, the melting point and purity change sharply with close relativity. After six months aging time, the melting point and purity of rubidium reach at 39.5℃ and 99.8% from initial 36℃ and 99.5% which is fit to the trend of rubidium consumption.

Key words: Rubidium discharge lamp, ⁺Differential Scanning Calorimetry (DSC), ⁺Rubidium consumption, ⁺Purity