XRS-2 | XRS-2
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For example, the CDP samples at 12288 Hz, so if the input signal contains frequencies higher than 6144 Hz the digital signal will not accurately represent the actual signal.
That is a rather incomplete description of aliasing. If you'd like to learn more, the University of California at Santa Cruz has a general discussion of converting a signal to digital form.
There are three ways that heat can travel: convection, conduction, and radiation. Conduction is what happens when you touch a cup of hot coffee; the heat flows from the hot cup directly to your skin. Convection is when a section of hot liquid or gas moves from one place to another. This happens in the air above your coffee -- a parcel of air just above the hot coffee is heated by conduction, and then, because it's lighter, that parcel rises, carrying heat by convection. The third way for heat to travel is by radiation. This is what you feel when you stand in the sunlight or near a hot fire.
In a dewar, the insulating material is a vacuum space. This eliminates conduction (since there is no material to conduct the heat) and convection (since there is no gas or liquid to convect). That leaves only radiation, which is stopped by covering the insides of the vacuum space with reflective material, which reflects nearly all the radiation before it enters the dewar.
The main XRS dewar contains solid neon at 17 Kelvin (17°C. above absolute zero). There is also a smaller dewar with 25 liters of liquid helium at 1.3 Kelvin.
Kelvin | °Celsius | °Fahrenheit | Notes |
---|---|---|---|
0 | -273.16 | -459.69 | Absolute zero |
273.16 | 0.0 | 32.0 | Triple point of water |
373.16 | 100.0 | 212.0 | Water boils |
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