Sample Probe:

It is a key component in NMR spectrometer which not only holds the sample in a fixed position in the magnetic field but also contains an air turbine to rotate (spin) the sample. The sample is spinned so as to ensure that it experiences a uniform field. In addition to these, it houses a coil for generating radiofrequency for excitation and also for detection of the NMR signal. Previously NMR spectrometers used to have separate transmitter and receiver coils perpendicular to every other for excitation of the pulse and detection of the signal. Modern spectrometers hold a single coil probe that is simple and more efficient. Because most of the continuous wave spectrometers use field sweep mode, a fixed frequency is produced from the radiofrequency generator and frequency synthesizer. The spectrometer is known through its operating frequency e.g., a 60 MHz, a 100 MHz or a 500 MHz instrument and so on. Therefore, in Fourier transform spectra, the sample is irradiated with a pulse consisting of a range of frequencies sufficiently great to excite nucleus having different resonance frequencies. The pulse of radiation provides a relatively broad band of frequencies centered on the oscillator frequency.