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These kits were sold to physics teachers throughout the United States. In 1975, after breakthroughs in bar coding technology, it developed the world's first hand-held helium–neon laser bar code scanner. These bar code scanners use a broad array of technologies including laser, holographic, vision-based, and radio-frequency identification ...
As the helium ion beam interacts with the sample, it does not suffer from a large excitation volume, and hence provides sharp images with a large depth of field on a wide range of materials. Compared to a SEM, the secondary electron yield is quite high, allowing for imaging with currents as low as 1 femtoamp. The detectors provide information ...
Helium is used as a tracer because it penetrates small leaks rapidly. Helium also has the properties of being non-toxic, chemically inert and present in the atmosphere only in minute quantities (5 ppm). Typically a helium leak detector will be used to measure leaks in the range of 10 −5 to 10 −12 Pa·m 3 ·s −1.
Helium is the least water-soluble monatomic gas, [96] and one of the least water-soluble of any gas (CF 4, SF 6, and C 4 F 8 have lower mole fraction solubilities: 0.3802, 0.4394, and 0.2372 x 2 /10 −5, respectively, versus helium's 0.70797 x 2 /10 −5), [97] and helium's index of refraction is closer to unity than that of any other gas. [98]
The amount of He in the spirometer is known at the beginning of the test (concentration × volume = amount). The patient is then asked to breathe (normal breaths) in the mixture starting from FRC (functional residual capacity), which is the gas volume in the lung after a normal breath out. The spirometer measures helium concentration.
A radionuclide identification device (RID or RIID) is a small, lightweight, portable gamma-ray spectrometer used for the detection and identification of radioactive substances. [1]
Chemical Agent Identification Sets (CAIS), known by several other names, were sets of glass vials or bottles that contained small amounts of chemical agents. They were employed by all branches of the United States Armed Forces from 1928-1969 for the purpose of training in detection, handling and familiarization with chemical warfare .
A flame test involves introducing a sample of the element or compound to a hot, non-luminous flame and observing the color of the flame that results. [4] The compound can be made into a paste with concentrated hydrochloric acid, as metal halides , being volatile, give better results. [ 5 ]