Patent ID: 7758317

Claim:
A vacuum solvent evaporator comprising: an airtight container for housing an object containing a single-component or multicomponent solvent; a dry diaphragm vacuum pump including a suction port from which a gas of the solvent evaporated in the airtight container is drawn, an exhaust port from which the gas is discharged; a gas ballast mechanism serving as an inert gas supply port; and at least four diaphragm pump chambers connected in series, each having a diaphragm pump chamber inlet through which gas is drawn and a diaphragm pump chamber outlet from which the gas is discharged, wherein the gas ballast mechanism is disposed between the outlet of the third or posterior diaphragm pump chamber upstream from the last diaphragm pump chamber and the inlet of the following diaphragm pump chamber; and further wherein the gas ballast mechanism disposed between the outlet of the third or posterior diaphragm pump chamber upstream from the last diaphragm pump chamber and the inlet of the following diaphragm pump chamber is the only gas ballast mechanism disposed between the diaphragm pump chambers; and an inert gas supply port through which an inert gas is supplied from the outside to the solvent gas drawn into the vacuum pump; inert gas supply means for supplying the inert gas into the vacuum pump through the inert gas supply port while the amount of gas supply is measured, thereby diluting the drawn solvent gas; inert gas supply amount storage means for storing the amount of inert gas supply measured by the inert gas supply means; a gas chromatograph for automatically sampling the gas discharged from the exhaust port of the vacuum pump at predetermined time intervals and measuring the solvent gas in the sampled gas; arithmetic operation means for calculating the concentration of the solvent gas from the measurement results of the gas chromatograph and a previously prepared calibration curve; and concentration data storage means for storing the solvent gas concentration obtained by the arithmetic operation means.