What is Induced polarization method?
Induced polarization (IP) is a geophysical imaging technique used to identify the electrical chargeability of subsurface materials, such as ore. In the time-domain induced polarization method, the voltage response is observed as a function of time after the injected current is switched off or on.
What causes Induced polarization?
Induced Polarization and Resistivity The IP is caused by the current placed into the earth “charging” specific mineral phases similar to a capacitor. The polarization measures the slow decay of voltage from this stored charge after the flow of electric current ceases (Sumner, 1978).
What is time domain Induced polarization?
Time Domain Induced Polarization (TDIP) Time domain Induced polarization consists of measuring the voltage decay after the cessation of transmitted current. The area under a designated portion of the decay curve can be integrated and offered as an IP measurement of chargeability.
What is chargeability geophysics?
Chargeability is a physical property related to conductivity. As we learned previously, ionic charges within a rock’s pore water begin to move under the influence of an electric field, resulting in electrical current.
How does the SP method work?
The self-potential (SP) technique is a passive electrical geophysical method based upon the measurement of spontaneous or natural electrical potential developed in the earth due to: 1) electrochemical interactions between minerals and subsurface fluids; 2) electrokinetic processes resulting from the flow of ionic …
What is electrode polarization?
Polarization is a mechanism that typically results in a change in the potential of an electrode during electrolysis, when the anode’s potential becomes nobler than that of the cathode. Polarization can also be described as a kinetic deviation from equilibrium due to an electric current passing through a galvanic cell.
How is metal factor calculated?
metal factor (MF) A frequency-domain measure of induced polarization where apparent resistivities are measured at two low frequencies, usually a factor of 10 apart in magnitude (ρ dc and ρ ac); MF = 2π10 5(ρ dc − ρ ac)/ρ ac 2.
How do you calculate chargeability?
Chargeability (payroll dollars) = direct labor in $/(direct labor in $ + indirect labor in $). The danger is that you can fall into the trap of believing that utilization is not a problem for your firm even though your profits are not where they should be.
What is resistivity method?
The electrical resistivity method involves the measurement of the apparent resistivity of soils and rock as a function of depth or position. It is calculated by dividing the measured potential difference by the input current and multiplying by a geometric factor specific to the array being used and electrode spacing.
What are the electromagnetic methods?
Electromagnetics. Electromagnetic (EM) methods use transmitters to create strong time-varying primary magnetic fields that induce electrical currents to flow in conductive rocks. These currents, in turn, create secondary electromagnetic fields that are detected by receiver antennae.
What is chemical polarization?
In electrochemistry, polarization is a collective term for certain mechanical side-effects (of an electrochemical process) by which isolating barriers develop at the interface between electrode and electrolyte.
What does polarization actually mean?
Polarization, also called wave polarization, is an expression of the orientation of the lines of electric flux in an electromagnetic field ( EM field ). Polarization can be constant — that is, existing in a particular orientation at all times, or it can rotate with each wave cycle.
What is direction of polarization?
polarization, n a process wherein the direction of electromagnetic radiation or light is limited to a particular plane. the production of that condition in light in which its vibrations are parallel to each other in one plane, or in circles and ellipses.
What is polarization effect?
Polarization is an effect that drives people so far apart on an issue it is as if they are at opposite poles.
What is a polarization curve?
A polarization curve is a plot of current density (i) versus electrode potential (E) for a specific electrode-electrolyte combination. Plots of log |i| vs. E or vs. (E – Eo) are called polarization curves. The polarization curve is the basic kinetic law for any electrochemical reaction.