The full width at half maximum (FWHM) of a peak (spectroscopic peak) is measured at half its highest height. The FWHM is usually reported by a spectrometer software package along with other spectral information about the peak.
For example, if a spectrum showed two peaks at 5 K with FWHMs of 20 pm and 25 pm, then the resolution of the spectrometer was 20 pm.
In general, the FWHM provides an estimate of the precision with which chemical shifts can be determined from a nuclear magnetic resonance spectrum. A narrow line indicates that the sample under study contains only a few different chemicals with very close chemical shifts; a broad line indicates that the sample contains many different chemicals with little preference for any particular chemical shift value.
Nuclear magnetic resonance spectroscopy is a well-known method for determining the composition of materials and their structures. In this method, atoms within the material under study emit weak radio waves when exposed to a strong magnetic field. These radio waves are called "magnetic moments" because they have a tendency to align themselves with the field. The frequency at which these magnetic moments oscillate into alignment or out of alignment with the magnetic field is dependent on the properties of each atom.
In a distribution, full width at half maximum (FWHM) is the difference between two independent variable values at which the dependent variable equals half of its maximum value. It can also be expressed as the distance divided by the intensity ratio at which the values are equal.
The FWHM of a distribution is often interpreted as the range within which you will find the same frequency of occurrences as in the maximum value. That is, if we divide the maximum value by the FHWM, we get an integer number of occurrences per unit length.
For example, if the maximum reading on a histogram is 300 and the FHWM is 100, then there are 3 times as many occurrences of the data between 100 and 200 as there are between 200 and 300. Thus, some parts of the curve are overrepresented in comparison to others.
This means that observations that fall outside this range are unusual relative to the rest of the sample. So, while it is possible to measure positions beyond FHWM-1 or FHWM+1, they are unlikely to happen again given our current sample of readings.
FHD is an abbreviation for Full High Definition. In computers, FHD indicates that the display is capable of displaying @1920x1080 pixels. The most common FHD displays are those with a resolution of 1920 by 1080 pixels.
The first thing you should know about FHD displays is that they are usually much bigger than HD displays. Most modern FHD screens are between 15 and 17 inches diagonally, while most HD screens are under 12 inches. Even if you will be using only one screen at a time, make sure you get a model with a size that's suitable for your needs or desires. You might want to buy two smaller screens if you plan to use them simultaneously.
Some people may not like how big FHD displays are. If this is the case for you, then you should consider buying only one or two of these screens. There are many small screens available that have a resolution of 1440 by 900 or 1280 by 1024.
Also, note that some FHD displays are larger than others. For example, some models from Dell measure about 18 inches diagonally, while others are only 15 inches. If you need a very large screen, it might be best to look into purchasing two smaller screens instead.