Measuring method of liquid mixture purity and apparatus for measuring liquid mixture purity

An apparatus for measuring liquid mixture purity, comprising:

• a storage tank, wherein the storage tank is configured for storing a liquid mixture, and the liquid mixture comprises formic acid and water;
• a calculating unit, wherein the calculating unit is coupled with the storage tank, and a plurality of formic acid purity values under different pressure and different temperature are saved in the calculating unit;
• a thermometer, wherein the thermometer is partially arranged in the storage tank, and the calculating unit is electrically or signally connected to the thermometer;
• and
• a pressure gauge, wherein the pressure gauge is partially arranged in the storage tank, and the calculating unit is electrically or signally connected to the pressure gauge;
• wherein the pressure gauge measures in an inner space of the storage tank which is vacuum to obtain a pressure value, and the thermometer measures the liquid mixture simultaneously to obtain a temperature value;
• wherein the pressure value and the temperature value are input into the calculating unit, and the calculating unit outputs one of the plurality of formic acid purity values corresponding to the pressure value and the temperature value;
• wherein the liquid mixture has a real purity value, the real purity value is a percentage by weight of the formic acid in the liquid mixture, and the real purity value is larger than 85 wt. %.