Method for determining the volume ratio of ethanol alcohol in liquor - Master's thesis - Dissertation

**Purpose of the Experiment** 1. Understand how to determine the alcohol content in traditional liquor. 2. Learn the principle behind measuring sample concentration. 3. Gain hands-on experience with using a refractometer. Liquor comes in many different degrees, and whether it's low or high in alcohol, people often don't fully understand what "degree" really means. The alcohol content refers to the percentage of ethanol in the drink. For example, 60° white wine means that 60% of the liquid is alcohol, and the remaining 40% is mostly water. In ancient China, there was no official alcohol table or modern measuring devices. People used simple methods like observing the "flower" effect when pouring wine into a basin. They would look at how the wine flowed and how long the bubbles lasted. This method could estimate the alcohol content with about 90% accuracy. Another old technique involved burning the wine. By igniting the liquor and observing how much water remained after the flame went out, people could estimate the alcohol level. However, this method was less accurate because it was influenced by external conditions such as temperature and air pressure. After the founding of the People's Republic of China, the use of a "wine table" became standard. A refractometer was introduced to measure alcohol content more accurately. The process involves filling a glass cup with the liquor, taking a small sample, and placing it on the refractometer's prism. After a few seconds, the device displays the alcohol volume ratio. In ancient times, without advanced tools, brewers used fire to test the alcohol level. They mixed equal parts of wine and lit it. If the flame burned brightly, the alcohol content was high; if it was weak or blue, the content was lower. This method was known as "proof," and today, the term is still used internationally to describe the strength of alcoholic drinks. There are three main ways to express alcohol content globally: Standard Alcohol (Vol), Sikes, and Proof. When 1 ml of pure alcohol is present in 100 ml of liquor, it’s considered 1 degree, or 1% Vol, also called 1 GL. Liquor is typically measured at 20°C. If the temperature is below 20°C, every 3 degrees below adds 1 degree of alcohol. If the temperature is above 20°C, every 3 degrees above subtracts 1 degree of alcohol. Here is a refractive index table for liquor at 20°C:

**Experimental Instruments and Reagents** - Instruments: PAL-33s Ethanol Refractometer, mirror paper, filter paper - Reagents: Absolute ethanol, distilled water, white wine **Experimental Procedures** 1. **Preparation of Ethanol-Water Solutions:** Prepare five working solutions containing 10%, 30%, 40%, 50%, and 60% ethanol by volume. 2. **Calibration of the Refractometer:** - Clean the prism with cotton balls and dry it. - Add 3–5 drops of distilled water onto the prism using a dropper (without touching the prism). - Press “START” to check the display. If it shows “0.0,” the instrument is ready. Otherwise, press “ZERO” to reset. - Dry the prism and repeat the calibration to ensure accuracy. 3. **Sample Measurement:** - Clean the prism surface. - Drop approximately 0.3 ml of the sample onto the prism. - Press “START.” The device will display “---” before showing the Brix value and temperature. - The Brix value will remain visible for 2 minutes. - To turn off the device, hold “START” for more than 2 seconds. - Wipe off the sample with a paper towel or gauze, rinse the prism with water, and dry it thoroughly. **Precautions** - Do not use metal spoons, as they may scratch or damage the prism. - Ensure the sample temperature matches the ambient temperature. Adjust if necessary before calibrating. - Avoid touching the sample if it exceeds 30°C, as it may affect the instrument's casing and waterproofing. - For high-temperature or viscous samples, use a small spoon to avoid spills. - If the screen displays “nnn,” cover the sample chamber and press “START” again. Always clean the prism thoroughly and check for errors. This experiment provides a practical understanding of how alcohol content is measured and emphasizes the importance of precision and proper handling of equipment.

Diamond Blade Grinding Machine

Diamond Blade Grinding Machine,Thin Core Drill Segment Grinding Machine,Trapezoidal Large Segment Grinding Machine,Automatic Trapezoidal Big Grinding Machine

Suzhou Mountain Industrial Control Equipment Co., Ltd , https://www.szmountain.com