2 图4-1密度瓶 1带毛细管的普通密度瓶 2一带温度计的精密密度瓶
• Use method： ➢ Before use, the pycnometer must be thoroughly cleaned with a mixture of potassium dichromate and concentrated sulfuric acid, rinsed thoroughly with water, and dried. ➢ To avoid changes in volume, the pycnometer must not be subjected to excessive temperature or pressure changes. ➢ Bubbles are the most common sources of relatively large errors. Whenever possible the liquid should be boiled and cooled shortly before filling
• Use method： ➢ Before use, the pycnometer must be thoroughly cleaned with a mixture of potassium dichromate and concentrated sulfuric acid, rinsed thoroughly with water, and dried. ➢ To avoid changes in volume, the pycnometer must not be subjected to excessive temperature or pressure changes. ➢ Bubbles are the most common sources of relatively large errors. Whenever possible the liquid should be boiled and cooled shortly before filling
1.3.2 hydrometric method (密度计法) • Archimedes principle? The upword buoyant force exerted on a body immersed in a liquid is equal to weight of the displaced liquid
1.3.2 hydrometric method (密度计法) • Archimedes principle? The upword buoyant force exerted on a body immersed in a liquid is equal to weight of the displaced liquid