Tuning the 300 Probe

The Auto Switchable 4-nucleus probe (¹³C/³¹P/¹H/¹⁹F) is not tunable.

The other 3 probes are tunable.

Why would you want to tune the probe?
1) You want to detect a nucleus other than proton or ¹³C.

2) If the probe is not tuned to your sample, the pulse width for full excitation will be longer than standard. The sensitivity will thus be less. Even if the pulse width for full excitation were calibrated, the sensitivity will be less.

Why would you need to tune the probe?
1) You sample is not similar to the standard conditions CDCl3 at 25ºC. Tuning is very dependent upon solvent and temperature.