Introduction - GDD Instrumentation MPP-EM2S Plus Instruction Manual

1. Introduction

Thank you for choosing the MPP-EM2S+ Multi Parameter Probe developed by Instrumentation GDD
Inc. to help you optimize your prospecting efforts. This probe will help you to better determine the
nature, the exact position as well as the intensity of magnetic/conductive horizons along your cores
and samples. The simplicity of the measurement process and the automatic recording will allow you
to easily obtain conductivity and magnetic susceptibility profiles corresponding to the core.
Here are the key benefits of the new MPP-EM2S+ probe:
• It provides you the ability to measure at all time the magnetic susceptibility with or without the
presence of a conductor such as pyrrhotite.
• It has improved software to measure in continuous mode using a time base with specific lengths
of your choice.
• It is equipped with new software to quickly create a profile from the measurements taken in
continuous mode.
Because the probe's response towards a conductor is similar to a conventional electromagnetic (EM)
survey's response, it will provide you more significant information than an ohmmeter or a visual
interpretation would do. To give an example, if the conductive zones of your core are evaluated by an
ohmmeter, the occurrence of chalcopyrite will induce a reading corresponding to a conductive zone.
In fact, chalcopyrite, even if it seems massive, will often not produce an anomaly detectable by an EM
survey. Along the core, the MPP-EM2S+ probe will have a similar response as the EM response and
will only indicate the conductors detectable by this type of survey. The use of the MPP-EM2S+ probe
could, therefore, prevent you to beginning an EM survey campaign for a type of ore that would not
respond to this approach.
In the previous example, the phenomenon that explains the absence of conductivity is probably
related to the chalcopyrite ore distribution in the sample. If the chalcopyrite grains are not touching
each other but are linked only by very thin filaments, the ohmmeter will detect the conductor
presence because of these tiny filaments connecting them. However, the grains, being linked only by
those filaments, will not form a sufficient surface to be detected by the probe.
For an equivalent content of conductive material, the probe's response will be higher in function of
the conductor's surface. You could try the following experience. Take an aluminium paper foil (a few
cm²), put the probe on the sheet and note the intensity of the anomaly. Roll the sheet in a small ball,
put the probe on the ball and take the reading again. You will see that the intensity of the anomaly is
higher for a larger contact surface even if the substance conductivity and quality are the same.
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