Abstract: A temperature adjustable airflow device includes a vortex tube having a high pressure gas inlet and cooled and heated outlets. A mixing chamber is provided having first and second ends, one gas inlet end at the first end and a gas outlet end at the second end, and an intermediate gas inlet end between the first and second ends. A high pressure inlet conduit is connected to the high pressure gas inlet of the vortex tube and to the gas inlet of the mixing chamber. The cooled or the heated vortex tube outlet is connected to the intermediate gas inlet end, the mixing chamber mixing high pressure gas with cooled or heated gas, respectively, from the vortex tube to enhance the pressure of the cooled or heated gas emanating from the vortex tube. The arrangement allows cooled or heated gas from the vortex tube to be output for a given application at a higher pressure that would normally be available.

Abstract: A pen-like device having a scriber for scratching a deep groove in a yellow colored, metal article object, such as jewelry, being tested for the gold content thereof, and an applicator provided on an opposite end of the pen-like device for conveying an acid solution, which is housed within the pen-like device, onto, around and in the groove to observe whether there is a color change to the testing area, on which the acid solution was applied, making the the testing area darker or black, where such a color change would indicate that the metal article or object is imitation gold, or has a gold content which is less than minimum karat requirement of the test.