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Vicat softening temperature or Vicat hardness is the determination of the softening point for materials that have no definite melting point, such as plastics. It is taken as the temperature at which the specimen is penetrated to a depth of 1 mm by a flat-ended needle with a 1 mm 2 circular or square cross-section.
This is achieved by drawing surrounding air in and exhausting it through a HEPA filter to remove potentially hazardous microorganisms. Laminar flow cabinets exist in both horizontal and vertical configurations, and there are many different types of cabinets with a variety of airflow patterns and acceptable uses.
A Soxhlet extractor is a piece of laboratory apparatus [1] invented in 1879 by Franz von Soxhlet. [2] It was originally designed for the extraction of a lipid from a solid material. Typically, Soxhlet extraction is used when the desired compound has a limited solubility in a solvent, and the impurity is insoluble in that solvent. It allows for ...
Drawing of a Thiele tube with red arrows showing convection current A photograph of a Thiele tube. The oil level is a little low now to compensate for expansion when heating commences. The Thiele tube, named after the German chemist Johannes Thiele, is a laboratory glassware designed to contain and heat an oil bath.
Historically, the definition of a scientific instrument has varied, based on usage, laws, and historical time period. [1] [2] [3] Before the mid-nineteenth century such tools were referred to as "natural philosophical" or "philosophical" apparatus and instruments, and older tools from antiquity to the Middle Ages (such as the astrolabe and pendulum clock) defy a more modern definition of "a ...
A wash bottle is a squeeze bottle with a nozzle, used to rinse various pieces of laboratory glassware, such as test tubes and round bottom flasks. Wash bottles are sealed with a screw-top lid. When hand pressure is applied to the bottle, the liquid inside becomes pressurized and is forced out of the nozzle into a narrow stream of liquid.
A nozzle protrudes from below into a drawing nozzle, via which the air is blown into the glass tube. The nozzle also holds the drawing onion so that it does not move out laterally. Since the quality and drawing speed achieved during the vertical tube drawing process are relatively low, this process has nowadays almost no practical significance.
Laboratory distillation set-up using, without a fractionating column 1: Heat source 2: Still pot 3: Still head 4: Thermometer/Boiling point temperature 5: Condenser 6: Cooling water in 7: Cooling water out 8: Distillate/receiving flask 9: Vacuum/gas inlet 10: Still receiver 11: Heat control 12: Stirrer speed control 13: Stirrer/heat plate