Nonpolarizing electrode (medium)

In Figure 1. you can see a nonpolarizing electrode which is free of potentials caused by electrochemical action between the electrode and the ground (R. E. Sheriff: Encyclopaedic Dictionary of Exploration Geophysics, Third Edition, p. 207). Its cylindrical body is made of PVC. The body is filled up with lead chloride saturated hard gel and a lead spiral is cemented in it.

Utilization:

Nonpolarizing electrode is used in geoelectrical and electromagnetic surveying especially in spontaneous potential (SP), resistivity, induced polarization (IP), telluric and magnetotelluric (MT) measurements.

Main features:

DC potential: a few mV Contact resistance: 30-300 W (for normal soils) Effective surface: 58 cm2 Mass: 1 kg Diameter: 90 mm Height: 80 mm

12-16 month long working life under normal conditions. It can be buried completely in the soil. Temperature drift: about 0.66 mikrovolt/C (using between 20-50 C)

Connection: isolated copper cable or tinned copper cable of 1-2.5 m length and 0.75-2.5 mm2 core, according to the order.

Safety regulations:

According to the laws and regulations concerning the manipulation of lead compounds.

Manufacturer:
WOLF Ltd
H-1195 Budapest, Hofherr Albert u. 3-15
Hungary
Phone/Fax: (36 1) 282 8881

Distributor and exporter:
Dr. Simon András geophisycist entrepreneur
1221, Budapest, Ringló u. 39.
Phone: 36 1 2261870
Fax: 36 1 3637256
Email: simandras@t-online.hu
www.geocities.com/simandras

Directions for use:

Transportation, storage: The nonpolarizing electrodes should be stored in their containers. There is an artificial sponge at the bottom of the container saturated with a special solution. The sponge should sometimes be soaked with distilled water (30 to 50 ml). The sponge must not be dried up and should be protected from sunshine. Deployment of the nonpolarizing elelectrodes: It is suggested to put the electrodes onto the plain wet soil resulting in a good contact between the soil and the electrode. Start of work: If one starts the work by putting the electrodes onto the soil, they reach the stationary (working) condition while the measuring device is prepared. End of work: after the work the nonpolarizing electrode should be washed down and put back into the container.

Special circumstances:

In the case of sandy soil and long measurements the soil around the nonpolarizing electrodes should sometimes be watered. The soil must not be dry up.
If the soil is strongly sandy it is recommended to put down 2-3 electrodes near each other. The isolation at the end of the electrode cables should be removed and the wires should be twisted together. The electrodes should be buried and the soil often watered.

In desert area several (2-3) nonpolarizing electrodes should be applied at a depth of several meters and they should be buried. The wires should be twisted together as mentioned above. Before the measurement the soil should frequently be watered and during the measurement this should be frequently be repeated.

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We have developed the medium nonpolarizing electrode in 1999. We think that their technical features are optimal for some of the field works.
However, we have been producing and selling nonpolarizing electrode with similar structure and technical features for 15 years but up to 1999 the volume and weight of electrode wa two times bigger. Several companies know our products and are satisfied with them.

Until now we have been selling 300-500 electrodes/year for the GEOSYSTEM, GEOINVEST, UNIVERSITA' DEGLI STUDI DI PADOVA, INSTITUTO DI GEOSCIENCE E GEORISORCE (Italy), for the GEOLOGICAL SURVEY OF FINLAND, for the UNIVERSIDADE DE LISBOA (Portugal), for the INSTITUTO COSTARRICENSE DE ELECTRICIDAD (Costa Rica), for the METRONIX Gmbh, BUNDESANSTALT für GEOWISSENSSCHAFTEN und ROHSTOFFE GEOZENTRUM HANNOVER (Germany), for the GEOPHYSICAL INSTITUTE ACAD. SCI. CZEH REPUBLIC, for the WOODS HOLE OCANOGRAPHIC INSTITUTION (USA), for the UNIVERSITAT de BARCELONA (Spain), and in Hungary for the EOTVOS LORAND GEOPHYSICAL INSTITUTE OF HUNGARY and for the MOL Hungarian OIL and Gas Co.

Price: 70 EURO/piece to European countries, including costs of delivery;
70 EURO/piece to other countries, costs of delivery according to the agreement.

NONPOLARIZING ELECTRODE (long)

This year we have developed new nonpolarizing electrode named "big" (see Fig. 3.). The purpose of this development is the decreasing of the contact resistance between the electrode and the ground.

Main features: diameter 121 mm, high: 90 mm, weight: about 2 kg., other features are the same as above.

Unit price: 78 EURO/piece

Distributor and exporter:
Dr. Simon András geophisycist entrepreneur
1221, Budapest, Ringló u. 39.
Phone: 36 1 2261870
Fax: 36 1 3637256
Email: simandras@t-online.hu
www.geocities.com/simandras