They can be stored in a freezer with a temperature of 0Â°F or less for 6 to 12 months. Refrigerated ground beef should be used within 1 or 2 days and can be stored in the freezer for up to 4 months. Leftover cooked beef that is refrigerated should be used within 3 or 4 days and can be frozen for up to 3 months.
A distortion analyzer is an electronic test instrument that measures the accuracy of an electronic circuit at reproducing a wave.For instance, an audio amplifier might have a sine wave input to it, and the distortion analyzer measures how close the output is to a sine wave.If the output is clipped, the wave will be distorted, and the analyzer will measure the amount of harmonics present.mplifiers will frequently have a Total Harmonic Distortion plus Noise specification which is an accurate term for the quantity measured by a distortion analyzer. There are many manufacturers of distortion analyzers. The Hewlett-Packard models 331a and 333 are laboratory standard instruments.
A hydrometer or areometer is an instrument that measures the specific gravity (relative density) of liquidsâthe ratio of the density of the liquid to the density of water. A hydrometer is usually made of glass, and consists of a cylindrical stem and a bulb weighted with mercury or lead shot to make it float upright. The liquid to test is poured into a tall container, often a graduated cylinder, and the hydrometer is gently lowered into the liquid until it floats freely. The point at which the surface of the liquid touches the stem of the hydrometer correlates to specific gravity.