title: Piezoelectric crystals generate NMR-like signals for rapid spectrometer troubleshooting.
abstract: Use of frequency-control quartz crystals for the generation of NMR-like signals via the piezoelectric effect is discussed. Such crystals are inexpensive and cover a wide range of RF frequencies. The crystal is connected to the spectrometer through a 30dB attenuator. Excitation by single, short RF pulses results in time domain signals similar to NMR FIDs. We show that the crystal should be shunted by a low resistance for largest Q (longest T2). By using odd higher overtones, the crystals were made to resonate at the high operating frequencies typical of modern spectrometers, here up to 630MHz. The performance of precision manufactured crystals is particularly better at high frequencies, compared to mass production crystals. The abundant and stable signal provided by the piezoelectric crystals yields a simple method for troubleshooting and testing NMR spectrometers.
authors.affiliation: Department of Physics, Washington University, Compton Hall, Campus Box 1105, One Brookings Drive, Saint Louis, MO 63130, USA. Electronic address: sbemery@wustl.edu.
authors.forename: Samuel B
authors.initials: SB
authors.lastname: Emery
authors.affiliation: Department of Physics, Washington University, Compton Hall, Campus Box 1105, One Brookings Drive, Saint Louis, MO 63130, USA. Electronic address: msc@wuphys.wustl.edu.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Conradi
mesh_terms: D017076:Computer-Aided Design; D004581:Electronics / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Piezoelectric; Quartz crystal; Spectrometer; Testing