Measuring Frequencies with iNMR
- Units. The fastest way to change the scale units is to press one of the following keys: p, H or n. You can also press a lower case h. p means ppm, H means Hz, n means points.
- Dialog. The command Format/Axes and Scales gives you more choices.
- The tool “info” is the solution to measure the central frequency of a peak, because it finds the nearest maximum and also performs a parabolic interpolation between the two upper neighbors. It does not require a click, but accepts the click and the right-click. The latter creates a permanent note. The underlying idea is that you'll spend a little time to make the note more readable and better formatted. The info tool can also be used to measure distances between peaks.
- An effective solution is that, for every spectrum, you spend a couple of minutes to create a few meaningful and good-looking notes. Quite often a spectrum contains only one or two really diagnostic values (Js or shifts). If you write them down once, you will save time in future. Writing too many values is less effective, because it makes more arduous, years later, to realize what the purpose of the spectrum was.
- The cross-hair tool does not find the nearest maximum. It reports the frequency value exactly corresponding to the mouse coordinates.
- The vertical and horizontal marks (Cmd-click and alt-click respectively) are more flexible. You can create many of them. They are a little more persistent. You can decide their numerical precision. Like the cross-hair, they don't look for peaks.
- When you synchronize two windows (commands: “Window/Tile” then “Window/Synchronize”) the first vertical mark and the first horizontal mark are duplicated in both windows.
- There is, of course, peak-picking.
- Peak-picking is one of the data sources of the J Manager. The latter keeps your data organized into a table, can format the numbers for publication and also includes a graph tool that draws the splitting tree annotated with the central shift and the individual coupling constants.