Name: calibrating lab glassware for accurate volume
Uploaded: 2024-12-05T18:31:54.000Z
Duration: 1 min 11 s
Channel: JoVE

정확한 부피 측정은 용액 기반 분석에 매우 중요합니다. 표준 부피 측정 장비에는 플라스크, 피펫 및 뷰렛이 포함됩니다.
부피 측정 플라스크는 특정 부피에 대한 용액을 준비하고 희석하는 데 사용됩니다. 그것들은 "포함하다"를 의미하는 TC로 표시되어 있습니다.
지정된 온도에서 정확한 부피를 포함하도록 보정되며, 최소 유리 팽창 계수는 사소한 변화에도 불구하고 거의 일정한 부피를 허용합니다.
TD라고 표시된 피펫은 주어진 온도에서 특정 부피를 전달합니다. 유리 벽의 필름 배수를 고려하여 보정되며, 이는 배송 시간에 따라 달라집니다.
적절한 보정을 거친 부피 측정 피펫은 최대 4개 또는 5개의 유효 숫자까지 단일 부피를 정확하게 전달합니다. 측정 피펫은 최대 3개의 유효 숫자의 낮은 정확도로 다양한 부피를 제공합니다.
뷰렛은 적정제를 고정하기 위한 보정된 튜브로, 적정제 흐름을 제어하기 위해 수동 밸브 시스템을 통해 정확하게 분배할 수 있습니다.

유리 기구 교정

볼륨 플라스크, 피펫, 뷰렛과 같은 유리 기구의 정확한 교정은 분석 실험실에서 정확한 측정을 보장하는 데 필수적입니다. 교정은 측정에서 일관성을 유지하고 부정확한 부피로 인해 발생하는 오류를 방지하는 데 도움이 됩니다. 볼륨 플라스크

볼륨 플라스크는 목에 교정선이 있는 정확한 부피의 수용액을 정확하게 준비하도록 설계되었습니다. 볼륨 플라스크를 교정하려면 메니스커스(액체의 곡선 표면)가 교정 표시와 일치할 때까지 증류수로 채우는 것이 중요합니다. 눈높이에서 메니스커스를 보면 정확한 판독값을 얻을 수 있습니다. 교정은 일반적으로 부피에 미치는 온도의 영향을 고려하기 위해 특정 온도(~20°C)에서 수행됩니다. 수위가 선 위에 있는 경우 표시에 도달할 때까지 조심스럽게 빼내고, 수위가 선 아래에 있는 경우 표시에 도달할 때까지 물을 한 방울씩 더 추가합니다. 교정 후 플라스크의 용량은 물의 무게를 측정하고 밀도에 따른 이론 값과 비교하여 확인할 수 있습니다.

피펫

피펫은 특정 양의 액체를 옮기는 데 사용됩니다.

용량 피펫: 일반적으로 4~5자리의 유효 숫자까지 단일의 매우 정확한 양을 전달하도록 설계되었습니다. 교정을 위해 피펫을 먼저 세척하고 측정할 용액으로 헹군 다음 교정 표시까지 채운 다음 용기에 완전히 비웁니다. 그런 다음 전달된 물의 무게를 측정하고 이를 물 밀도에 따른 이론 값과 비교하여 정확도를 확인합니다.

그래듀에이티드 피펫: 그래듀에이티드 피펫은 그래듀에이티드 피펫과 달리 일련의 선으로 표시되어 있으며 여러 양을 전달할 수 있지만 정확도는 약간 낮습니다. 일반적으로 최대 3자리의 유효 숫자입니다. 교정 및 측정 중에 메니스커스도 주의 깊게 관찰해야 합니다.

뷰렛

뷰렛은 한쪽 끝에 탭이 있는 길고 그래듀에이티드 유리 튜브로, 특히 적정에서 다양한 양의 용액을 정확하게 분배합니다. 뷰렛을 교정할 때는 적정 전후에 메니스커스가 표시와 올바르게 정렬되었는지 확인하고, 공급된 물의 무게를 이론 값과 비교하여 분주된 양이 예상대로인지 확인합니다. 뷰렛의 저수조에는 액체의 양을 나타내는 표시가 있습니다. 바닥에 있는 스톱콕이나 탭은 사용자가 저수조에서 액체 흐름을 제어할 수 있는 수동 밸브 역할을 하여 분주된 양을 정확하게 측정할 수 있습니다.

기타 유리 제품

메스 실린더와 같은 다른 유형의 실험실 유리 제품도 일반적으로 부피 측정에 사용되지만 부피 측정 장비보다 정확도가 낮습니다. 일반적으로 최대 3자리의 유효 부피를 제공하므로 덜 정확한 작업에 적합합니다. 그러나 이러한 품목의 교정은 여전히 ​​측정 신뢰성을 유지하는 데 중요합니다.

실험실 유리 제품을 교정하면 정확하고 신뢰할 수 있는 측정이 보장되며, 이는 분석 결과의 무결성을 유지하는 데 중요합니다. 용량 플라스크, 피펫, 뷰렛 또는 기타 유리 제품을 사용하든 적절한 교정 기술은 오류를 방지하고 실험실 작업의 정확도를 개선하는 데 도움이 됩니다.

부피 측정 플라스크, 피펫 및 뷰렛과 같은 유리 제품의 정확한 교정은 분석 공정에서 정확한 측정을 보장하는 데 필수적입니다.

Education

교육

JoVE Core

Analytical Chemistry

분석 화학

Unit 1

제1단원

Method Development and Sampling Techniques

분석법 개발 및 시료 채취 기술

method-development-and-sampling-techniques

KEY TERMS AND CONCEPTS

주요 용어 및 개념

Glassware Calibration

calibrating lab glassware for accurate volume

Calibrating lab glassware helps students measure liquids accurately in the analytical laboratory. It reduces volume errors and supports consistent results across measurements. This matters when using volumetric flasks, pipettes, burettes, and other tools that depend on precise volume readings.

Volumetric flasks are used to prepare aqueous solutions with a precise final volume. They have a calibration line on the neck. To calibrate one, fill it with distilled water until the meniscus, the curved surface of the liquid, lines up with the mark at eye level. This is usually done at about 20°C because temperature can affect volume. If the water rises above the line, drain it carefully. If it is below the line, add water drop by drop until it reaches the mark. The flask’s capacity can then be checked by weighing the water and comparing it with the theoretical value from its density.

Pipettes are used to transfer set amounts of liquid. Volumetric pipettes are made to deliver one highly accurate volume, often to four or five significant figures. To calibrate one, clean it and rinse it with the solution to be measured, fill it to the calibration mark, and let it drain completely into a container. The volume delivered is checked by weighing the water and comparing it with the theoretical volume based on water density. Graduated pipettes have a series of marks and can deliver different volumes, but they are slightly less accurate. They are generally used to about three significant figures, so the meniscus must still be read carefully.

Burettes are long, graduated glass tubes with a tap at one end. They are used to dispense variable amounts of solution, especially during titrations. When a burette is calibrated, the meniscus must be aligned with the markings before and after use. The volume dispensed is then compared with the expected value by weighing the water delivered. The reservoir shows the liquid level, and the stopcock, or tap, acts as a manual valve that controls flow for precise measurement.

Other glassware, such as graduated cylinders, is also used for measuring volume. These tools are less accurate than volumetric equipment, but they are still useful for work that does not need the highest precision. They usually measure up to three significant figures. Even so, calibration remains important for reliable measurements in the lab. Careful calibration of lab glassware helps protect the accuracy and integrity of analytical results.

Calibrating Lab Glassware for Accurate Volume

calibrating-lab-glassware-for-accurate-volume

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Measuring Analyte Concentration

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Calibrating Lab Instruments for Accurate Results

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glassware calibration

Calibrating lab glassware helps students measure liquids accurately in the analytical laboratory. It reduces volume errors and supports consistent results across measurements. This matters when using volumetric flasks, pipettes, burettes, and other tools that depend on precise volume readings. Volumetric flasks are used to prepare aqueous solutions with a precise final volume. They have a calibration line on the neck. To calibrate one, fill it with distilled water until the meniscus, the...

standard solutions

Preparing Standard Solutions in the Lab

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Blank Solutions in Analytical Testing

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Sample Transport and Storage Basics

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Sampling Errors in Sample Preparation

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key terms and concepts

Learn how volumetric flasks, pipettes, burettes, and graduated cylinders are calibrated to improve volume accuracy, consistency, and lab reliability.

Calibrating Lab Glassware for Accurate Volume | JoVE K12

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Calibrating Lab Glassware for Accurate Volume

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