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Humidity Indicator
A humidity indicator card (HIC) is a card on which a moisture-sensitive chemical is impregnated such that it will change color when the indicated relative humidity is exceeded. This has usually been a blotting paper impregnated with cobalt(II) chloride base; Less toxic alternatives include other chemicals such as cobalt-free chloride base and special plastic films. Humidity indicators are an inexpensive way to indicate or quantify moisture content inside sealed packaging. They are available in many configurations and used in many applications, especially military and semiconductor. The most common humidity indicator cards change color from blue (less than indicated RH level) to pink (greater than indicated RH level). History The need for an easily read humidity indicator that could not be damaged by vibration was identified during World War II. Rear Admiral Welford C. Blinn, at that time the Commander of the USS Pope, became concerned about the poor condition of the weapons an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relative Humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depends on the temperature and pressure of the system of interest. The same amount of water vapor results in higher relative humidity in cool air than warm air. A related parameter is the dew point. The amount of water vapor needed to achieve saturation increases as the temperature increases. As the temperature of a parcel of air decreases it will eventually reach the saturation point without adding or losing water mass. The amount of water vapor contained within a parcel of air can vary significantly. For example, a parcel of air near saturation may contain 28 g of water per cubic metre of air at , but only 8 g of water per cubic metre of air at . Three primary measurements of humidity are widely employed: absolute, relative, and specific. Ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Community
The European Economic Community (EEC) was a regional organization created by the Treaty of Rome of 1957,Today the largely rewritten treaty continues in force as the ''Treaty on the functioning of the European Union'', as renamed by the Lisbon Treaty. aiming to foster economic integration among its member states. It was subsequently renamed the European Community (EC) upon becoming integrated into the first pillar of the newly formed European Union in 1993. In the popular language, however, the singular ''European Community'' was sometimes inaccuratelly used in the wider sense of the plural '' European Communities'', in spite of the latter designation covering all the three constituent entities of the first pillar. In 2009, the EC formally ceased to exist and its institutions were directly absorbed by the EU. This made the Union the formal successor institution of the Community. The Community's initial aim was to bring about economic integration, including a common market and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Thermodynamics
Atmospheric thermodynamics is the study of heat-to-work transformations (and their reverse) that take place in the earth's atmosphere and manifest as weather or climate. Atmospheric thermodynamics use the laws of classical thermodynamics, to describe and explain such phenomena as the properties of moist air, the formation of clouds, atmospheric convection, boundary layer meteorology, and vertical instabilities in the atmosphere. Atmospheric thermodynamic diagrams are used as tools in the forecasting of storm development. Atmospheric thermodynamics forms a basis for cloud microphysics and convection parameterizations used in numerical weather models and is used in many climate considerations, including convective-equilibrium climate models. Overview The atmosphere is an example of a non-equilibrium system. Atmospheric thermodynamics describes the effect of buoyant forces that cause the rise of less dense (warmer) air, the descent of more dense air, and the transformation of water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desiccation
Desiccation () is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container. Industry Desiccation is widely employed in the oil and gas industry. These materials are obtained in a hydrated state, but the water content leads to corrosion or is incompatible with downstream processing. Removal of water is achieved by cryogenic condensation, absorption into glycols, and absorption onto desiccants such as silica gel. Laboratory A desiccator is a heavy glass or plastic container, now somewhat antiquated, used in practical chemistry for drying or keeping small amounts of materials very dry. The material is placed on a shelf, and a drying agent or ''desiccant'', such as dry silica gel or anhydrous sodium hydroxide, is placed below the shelf. Often some sort of humidity indicator is included in the desiccator to show, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperature Data Logger
A temperature data logger, also called temperature monitor, is a portable measurement instrument that is capable of autonomously recording temperature over a defined period of time. The digital data can be retrieved, viewed and evaluated after it has been recorded. A data logger is commonly used to monitor shipments in a cold chain and to gather temperature data from diverse field conditions. Construction A variety of constructions are available. Most have an internal thermistor or thermocouple or can be connected to external sources. Sampling and measurement are periodically taken and digitally stored. Some have a built in display of data or out-of- tolerance warnings. Data retrieval can be by cable, RFID, wireless systems, etc. They generally are small, battery powered, portable, and equipped with a microprocessor, internal memory for data storage, and sensors. Some data loggers interface with personal computers or smart phones for set-up, control, and analysis. Some inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Temperature Indicator
A time temperature indicator (TTI) is a device or smart label that shows the accumulated time-temperature history of a product. Time temperature indicators are commonly used on food, pharmaceutical, and medical products to indicate exposure to excessive temperature (and time at temperature). In contrast, a Temperature data logger measures and records the temperatures for a specified time period. The digital data can be downloaded and analyzed. Technology There are a large number of different time temperature indicators available in the market, based on different technologies. Some devices are based migration of dye through a filter paper, while others contain pouches with bacterial fluids that change color when certain time-temperature combinations have been reached. To the degree that these physical changes in the indicator match the degradation rate of the food, the indicator can help indicate probable food degradation. Digital Temperature data loggers are available to indi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moisture Sensitivity Level
Moisture sensitivity level (MSL) relates to the packaging and handling precautions for some semiconductors. The MSL is an electronic standard for the time period in which a moisture sensitive device can be exposed to ambient room conditions (30 °C/85%RH at Level 1; 30 °C/60%RH at all other levels). Increasingly, semiconductors have been manufactured in smaller sizes. Components such as thin fine-pitch devices and ball grid arrays could be damaged during SMT reflow when moisture trapped inside the component expands. The expansion of trapped moisture can result in internal separation (delamination) of the plastic from the die or lead-frame, wire bond damage, die damage, and internal cracks. Most of this damage is not visible on the component surface. In extreme cases, cracks will extend to the component surface. In the most severe cases, the component will bulge and pop. This is known as the "popcorn" effect. This occurs when part temperature rises rapidly to a high ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R Phrase
R-phrases (short for risk phrases) are defined in Annex III of European Union Directive 67/548/EEC: ''Nature of special risks attributed to dangerous substances and preparations''. The list was consolidated and republished in Directive 2001/59/EC, where translations into other EU languages may be found. These risk phrases are used internationally, not just in Europe, and there is an ongoing effort towards complete international harmonization using the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) which now generally replaces these risk phrases. Risk phrases Missing R-numbers indicate phrases that have been deleted or replaced by other phrases. Combinations R-phrases no longer in use * : Extremely flammable liquefied gas. * : May cause birth defects. See also * List of S-phrases * Material safety data sheet * Risk and Safety Statements {{short description, System of hazard codes and phrases for labeling dangerous chemicals and compounds Risk a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper(II) Chloride
Copper(II) chloride is the chemical compound with the chemical formula CuCl2. The anhydrous form is yellowish brown but slowly absorbs moisture to form a blue-green dihydrate. Both the anhydrous and the dihydrate forms occur naturally as the very rare minerals tolbachite and eriochalcite, respectively.Marlene C. Morris, Howard F. McMurdie, Eloise H. Evans, Boris Paretzkin, Harry S. Parker, and Nicolas C. Panagiotopoulos (1981) ''Copper chloride hydrate (eriochalcite)'', in Standard X-ray Diffraction Powder PatternsNational Bureau of Standards, Monograph 25, Section 18; page 33. Structure Anhydrous CuCl2 adopts a distorted cadmium iodide structure. In this motif, the copper centers are octahedral. Most copper(II) compounds exhibit distortions from idealized octahedral geometry due to the Jahn-Teller effect, which in this case describes the localization of one d-electron into a molecular orbital that is strongly antibonding with respect to a pair of chloride ligands. In CuCl2·2H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blotting Paper
Blotting paper, called bibulous paper, is a highly absorbent type of paper or other material. It is used to absorb an excess of liquid substances (such as ink or oil) from the surface of writing paper or objects. Blotting paper referred to as bibulous paper is mainly used in microscopy to remove excess liquids from the slide before viewing. Blotting paper has also been sold as a cosmetic to aid in the removal of skin oils and makeup. Manufacture Blotting paper is made from different materials of varying thickness, softness, etc. depending on the application. It is often made of cotton and manufactured on special paper machines. Blotting paper is reputed to be first referred to in the English language in the 15th century but there is a tradition in Norfolk, England that it was invented by accident at Lyng Mill on the River Wensum. It is reported that a Berkshire (England) paper mill worker failed to add sizing to a batch of paper that was being produced. The batch was discarde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
6 Spot Humidity Indicator Card
6 (six) is the natural number following 5 and preceding 7. It is a composite number and the smallest perfect number. In mathematics Six is the smallest positive integer which is neither a square number nor a prime number; it is the second smallest composite number, behind 4; its proper divisors are , and . Since 6 equals the sum of its proper divisors, it is a perfect number; 6 is the smallest of the perfect numbers. It is also the smallest Granville number, or \mathcal-perfect number. As a perfect number: *6 is related to the Mersenne prime 3, since . (The next perfect number is 28.) *6 is the only even perfect number that is not the sum of successive odd cubes. *6 is the root of the 6-aliquot tree, and is itself the aliquot sum of only one other number; the square number, . Six is the only number that is both the sum and the product of three consecutive positive numbers. Unrelated to 6's being a perfect number, a Golomb ruler of length 6 is a "perfect ruler". Six is a con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface-mount Device
Surface-mount technology (SMT), originally called planar mounting, is a method in which the electrical components are mounted directly onto the surface of a printed circuit board (PCB). An electrical component mounted in this manner is referred to as a surface-mount device (SMD). In industry, this approach has largely replaced the through-hole technology construction method of fitting components, in large part because SMT allows for increased manufacturing automation which reduces cost and improves quality. It also allows for more components to fit on a given area of substrate. Both technologies can be used on the same board, with the through-hole technology often used for components not suitable for surface mounting such as large transformers and heat-sinked power semiconductors. An SMT component is usually smaller than its through-hole counterpart because it has either smaller leads or no leads at all. It may have short pins or leads of various styles, flat contacts, a matrix ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
