The nuclear magnetic resonance probe based on a printed circuit board planar microcoil

The nuclear magnetic resonance (NMR) probe, one of the most important components in the spectrometer, has a considerable impact on overall instrument sensitivity. By the concept of a NMR analyzer with low-cost and portable was proposed in recent years, the earlier NMR probes were not suitable for the manufacture cost and cycle time. So, in this paper, a NMR probe based on the printed circuit board (PCB) planar microcoil was developed for time domain NMR measurement. When the Larmor frequency is 28.1 MHz, the NMR transverse relaxation time T₂ of a deionized water sample was detected by the 2mm inner diameter PCB microcoil with six turns, and results of T₂ measured value were stable under different scan times. In addition, relaxation times of used frying oil and three edible oils were analyzed by the PCB microcoil, both T₂₂ and T₂₃ components of used frying oil, obviously less than three edible oils, these results are agreed with the measurement of a commercial instrument Bruker minispec mq60.