Standard ¹⁵N sensitivity test sample: 90% formamide in DMSO-d₆.

Insert the sample (ij).

Choose the solvent deuterium signal with the lock command

Tune and match the probehead (wobb or atma if required).

Optimize the shim procedure (read an optimized shim file with the rsh command or performs a gradshim if required).

Record a ¹H-decoupled ¹⁵N spectrum.

The calibration of the ¹⁵N sensitivity test is performed using the standard ¹H-decoupled ¹⁵N parameter set (the pulse program is set to pulprog zgig). This test is performed using the inverse gated decoupling scheme in order to avoid the build up of NOE. 

It is very important to use a long recycle delay, usually d1=5*T1(¹⁵N) (for instance d1=500 s). Use a single scan (ns=1).

Set p1 to the 90º ¹⁵N observe pulse at high power level pl1. This pulse is calibrated reaching the maximum signal for 90º and null point in 180º.

Start acquisition by rga and zg (the expected experimental time is displayed with the expt command).

The recorded data is Fourier transformed with ft (or ef) and phase and baseline corrections are performed using apk and abs, respectively. Modify processing parameters if required from the ProcPars section or using the ased command.. Reference the line to 0 ppm and plot the full spectrum.

Use the TOPSPIN plot editor (xwinplot)  Plot the noise with a minimum amplitude of 1.5 cm over a minimum of 100 Hz.