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 content. 3. Gain hands-on experience with using a refractometer. Liquor comes in many different strengths, whether it's low or high in alcohol content. Many people aren't fully aware of what these numbers truly mean. The alcohol content, or "degree," refers to the percentage of pure alcohol in the drink. For example, 60° white wine means that 60% of its volume is alcohol, and the remaining 40% is mostly water. In ancient times, before modern tools were available, people used simple methods to estimate alcohol levels. One common technique was to observe the "flower" effect when pouring the wine into a basin. Another method involved burning the wine and checking how much liquid remained after combustion. These techniques, while practical at the time, were not always accurate due to external factors like temperature or flame intensity. After the establishment of the People's Republic of China, more precise methods were introduced, such as using a "wine table" and a refractometer. This involves placing a small sample of the liquor into a refractometer and measuring the refractive index to determine the alcohol concentration. Historically, brewers would mix equal parts of wine and then ignite it. If the fire burned brightly, it indicated a higher alcohol content. A medium blue flame meant a moderate level, while no flame suggested a lower concentration. This method, known as "proofing," led to the development of the term "proof" in English, which is still used today to express alcohol content. Globally, there are three main ways to express alcohol content: Standard Alcohol (Vol), Sikes, and Proof. In most countries, 1% Vol means 1 ml of pure alcohol per 100 ml of liquid. When measuring alcohol content, the standard temperature is 20°C. If the temperature of the liquor differs, adjustments are made. For every 3°C below 20°C, the alcohol content increases by 1 degree, and for every 3°C above, it decreases by 1 degree. Here’s a refractive index data sheet for liquor at 20°C: **Experimental Instruments and Reagents** - Instruments: PAL-33s ethanol refractometer, mirror paper, filter paper. - Reagents: Absolute ethanol, distilled water, and white wine. **Procedure** 1. **Preparation of Ethanol-Water Solutions**: Prepare five working solutions with ethanol concentrations of 10%, 30%, 40%, 50%, and 60% (v/v). 2. **Calibration of the Refractometer**: - Clean the prism with a cotton ball and dry it thoroughly. - Use a dropper to add 3–5 drops of distilled water onto the prism. - Ensure the dropper does not touch the prism. - Press the “START” button. The screen should display “0.0.” - If not, press “ZERO” to calibrate. - Repeat the process to ensure accuracy. 3. **Sample Measurement**: - Clean the prism surface. - Add approximately 0.3 ml of the sample to the prism. - Press the “START” button. - The instrument will display “---,” followed by the Brix value and temperature. - The Brix value will remain on the screen for two minutes. - To turn off the device, hold the “START” button for more than two seconds. - Wipe the sample away with a paper towel or gauze, rinse the prism with water, and dry it carefully. **Precautions** - Avoid using metal spoons, as they can scratch or damage the prism. - Ensure the sample temperature matches the ambient temperature. Adjust if necessary before calibration. - Do not touch the sample if it exceeds 30°C, as this may cause damage to the device’s casing and affect its waterproof performance. - When handling high-temperature or viscous samples, use a small spoon to avoid spills. - Never clean the prism with water hotter than 30°C, as it may damage the outer casing. - If the screen displays “nnn,” cover the sample chamber and press the “START” button again. - Always clean the instrument thoroughly and check for errors after each use. This experiment provides valuable insight into the science behind determining alcohol content and helps develop practical skills in using precision instruments like the refractometer.

Diamond Tool Equipment Spare Parts

Diamond Tool Equipment Spare Parts,Large Saw Blade Sharpening Machine,Large Diamond Saw Blade Sharpening,Bellows Cover For Testing Machine

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