Sometimes the temperature does not decrease with height in the troposphere, but increases. Such a situation is known as a temperature inversion. Temperature inversions limit or prevent the vertical mixing of air.
Middle range machines can cost on average $400 and are often multi-function with copier and laser printer capabilities. Finally, high-end machines which offer high speeds, high capacity and high resolution come at a higher price-expect to pay $1000 - $2500 for such a fax machine.
Here's the information essential to avoid these problems when buying a fax machine. Environmental Protection Agency, one of the most energy-intensive pieces of business equipment is the paper-intensive fax machine because it is often left on around the clock.