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Suggested Paleo-Magnetizm Combinations
Paleo-Magnetic equipment offered by Molspin centres on standard 1" (25.4mm) diameter x 1" (25.4mm) long cylindrical rock samples. These samples enable the identification of the magnetic north pole vector when the rocks were first laid down. Removal of "soft" or secondary magnetizm resulting from drift from when first laid down can be achieved by de-magnetizing the samples. De-magnetizing can also allow the user to make an assessment of the proportions of ferritic materials in the sample.
Spinner Magnetometer
As a minimum (unless you already have one), you will need a spinner magnetometer. These devices spin the rock sample in a shielded enclosure within coils to identify the North pole magnetic vector. Molspin's Minispin is designed to work in the field (or in a laboratory) and, when linked to a laptop computer, provides the perfect field research capability. The magnetometer operates continuously for around 8 hours on a single charge and the unit can be recharged from the cigarette lighter in a car/van.
To jump to the datasheet for the Minispin, click here. Please note that the large sample Minispin is not recommended here.
Demagnetizer
You will need a demagnetizer of one form or another to remove the viscous remanent or post depositional remanent magnetizm added to the sample by the environment after the sampled rock was laid down. There are two options to choose from here being a Field Demagnetizer and a Thermal Demagnetizer. Each method has its own merits and you should investigate both before choosing the method you wish to adopt (the best laboratories have both methods available to them). Molspin provides a field demagnetizer which tumbles the sample in two axes to ensure maximum secondary maznetizm removal.
Molspin's demagnetizer provides fields of up to 1500 Oersteds (depending upon the version selected). Power consumption is around 700W allowing use from a domestic supply.
To jump to the datasheet for the Demagnetizer, click here.
One of the advantages of a field demagnetizer is the ability to study Anhysteretic Remanent Magnetization where samples are subjected to a small constant DC field in a reducing AC field. If you wish to study this then you will need an ARM unit, the datasheet for which can be found here.
If you are particularly interested in characterising magnetic particles, you could opt for the PARM (Partial Anhysteretic Remanent Magnetizationunit which again provides a small constant DC field for the sample but allows the user to choose the AC field intensity at which the field starts as well as the peak field encountered. The AC field is then reduced and cuts off at the original starting point. The data sheet for the PARM unit can be found by clicking here.
For a thermal demagnetizer, Molspin suggests those made by Magnetic Measurements Ltd which can be found by clicking here.
Pulse Magnetizer
You will need a pulse magnetizer if you intend to study isothermal remanent magnetization (IRM). These devices provide a large pulse of magnetising field (up to 1 Te) over a very short period (1/100 second). This is achieved using a capacitor bank but has the advantage that the power consumption is around 100W - easily possible from a domestic power supply.
Molspin's pulse magnetizer provides fields of up to 1 Tesla and (depending upon the version selected) down to 0.1 T with precision.
To jump to the datasheet for the Pulse Magnetizer, click here.
Don't forget when ordering to indicate that the equipment is to be used for paleo-magnetizm!