Status: this preprint is open for discussion and under review for Geoscientific Instrumentation, Methods and Data Systems (GI).
Surface NMR groundwater measurements with dual transmitters
Sikender Gul,Matthew Peter Griffiths,Michel Hardenberg,and Jakob Juul Larsen
Abstract. One of the controlling factors for the depth of investigation in a groundwater measurement with surface NMR is the available excitation current. Increasing this current is generally a difficult and costly engineering challenge. In this paper, we experimentally demonstrate a different approach towards higher excitation currents. We simultaneously operate two surface NMR instruments with overlapping transmitter coils, which effectively turn them into one instrument with a maximum current twice as large as a single instrument. An analysis of the NMR excitation pulses shows that the combined pulses are very stable with negligible amplitude and timing errors. A field example is provided where data from a single instrument and from the dual instrument setup are compared. The paper contains a discussion on how this approach can be extended to novel surface NMR transmitter strategies.
Received: 18 Sep 2026 – Discussion started: 19 Oct 2026
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One of the controlling factors for the depth-of-investigation in groundwater measurements with surface nuclear magnetic resonance (NMR) is the maximum current of the transmitter pulses. Increasing the maximum current of a surface NMR transmitter is generally a costly and difficult engineering challenge. However, the challenge can be partially circumvented by operating two (or more) transmitter units in unison. We demonstrate the approach with a field measurement at a well characterized site.
One of the controlling factors for the depth-of-investigation in groundwater measurements with...
