Method Water Vapor Permeability

Oxygen and water vapor have obvious influence on active substance of food, pharmaceuticals and some cosmetics, which make chemical property of these products unstable. Therefore, commercial packaging usually raises demand on barrier property of specimen materials. At present, the fundamental method of water vapor permeability testing-gravimetric method is provoking criticism in terms of its test efficiency and test repeatability, etc. The expansibility of gravimetric method and whether gravimetric method will be replaced have become the focus of concern. This article presents a systematic analysis of test principle, present situation and prospect of gravimetric method.

Processing Maple Syrup with a Vapor Compression Distiller

A test of vapor compression distillers for processing maple syrup revealed that: (1) vapor compression equipment tested evaporated 1 pound of water with .047 pounds of steam equivalent (electrical energy); open-pan evaporators of similar capacity required 1.5 pounds of steam equivalent (oil energy) to produce 1 pound of water; (2) vapor compression evaporation produced a syrup equal in quality to that from a conventional open-pan evaporation plant; and (3) a central plant prodrucing 8,000 gallons of syrup per year should yield a return of 16 percent on investment. Increasing annual product output should increase the return on investment.

Water Vapor Confirmed a Major Greenhouse Gas

Water vapor is one of the most powerful greenhouse gases. As the
oceans warm, thanks to rising levels of CO2, they evaporate water
vapor more freely into the atmosphere. Similarly, as the land surface
warms, it too evaporates more water vapor into the warming atmosphere.

As the atmosphere warms, thanks to rising levels of CO2, it can hold
more water vapor.

Vapour Pressure

Water vapour is one of several gaseous constituents of air, the other principal ones being nitrogen, oxygen and carbon dioxide. Each exerts its own partial pressure in proportion to the amount of gas present, the sum of the pressures making up the total or barometric pressure of the air. When there is a difference in concentration of one of these gases between two points, there will be a corresponding difference in partial pressure. This will cause a flow of that particular gas from the point of higher concentration to the lower. When a partial pressure difference exists between two sides of a material, the gas involved will diffuse through the material until the partial pressures of that gas are equalized.

The rate of diffusion will be determined by the partial pressure difference, the length of the flow path, and the permeability to the particular gas involved of the medium through which flow is taking place.

Portable Gasoline Analyser

IROX 2000 is an extremely compact, robust and user friendly Mid-FTIR spectrometer for the automatic measurement of the concentration of the most important components of gasoline.

Thanks to an improved mathematical model and the use of a built-in density meter the instrument provides enhanced results for the prediction of key properties such as Octane Numbers, Distillation Properties and Vapor Pressure. A large number of country specific calibration samples is stored. Outlier fuels can be easily added even without a PC.

The portability and vehicle battery options are ideal for on-site field use.