Geometrics.com

Testimonials - Magnetometers

We have found that the Geometrics G-880 magnetometer as reliable as any instrument we have ever used in marine applications. The lack of noise in 880 data collected, even in the most difficult environments, is of course the most notable feature that we have found but its outstanding reliability is an added, and greatly welcomed, benefit.

We have owned the magnetometer for about 10 years and have found it to be like the famous watch, even if it takes a lickin' it keeps on tickin' . From locating UXO to pinpointing the iron sounding board from a long submerged piano we have successfully used it in myriad search operations. Congratulations on building a fine instrument.

Recently we located a famous ship, the 6-masted Wyoming which was lost in a violent storm in 1924 off the coast of New England. At 329 feet in length and a loaded displacement of nearly 10,000 tons, she was the largest wooden vessel ever to carry a cargo.

Extensive sonar operations were sporadically carried out between 1978 and 2002 in search of the Wyoming. Although many wrecks were found in the area, the great schooner eluded us. In 2003 it was decided to use an 880 cesium vapor magnetometer because the ship, although constructed mainly of wood, was built with iron strapping to bind the ship's frames. Also, the region where she went down is very active and sediments are mobile in the area thus burial was a very real possibility.

The mag, as usual, performed magnificently. Once we located the ship, we were able to determine that the presence of the iron was all along the hull by towing the sensor longitudinally down the wreck. It made sense that an anchor and chain in the forecastle would have been a much more localized anomaly. Finally the wreck was imaged with sonar and inspected optically for final confirmation. The ship will be preserved and studied to give us more information concerning the art of constructing one of the world's biggest wooden ships

H. Arnold Carr
American Underwater Search & Survey, Ltd.


"I would like to tell you that our 858 Magnetometer is working great even after about 10 years of use. I have been retired a couple of years now and am working with our archaeologists."

Chuck Young


...and thanks again to you and the others for everything you did to help in this (G-882-TVG) project which lasted 7 months without any major problems...

Farokh Patel
EGS Survey


I have attached an example of the sort of thing that we usually use your magnetometers for. Its a single-sensor survey using the ag132 for guidance. The transect interval is very coarse for archaeology (2 meter spacing), which is why we refer to it as a reconnaissance survey. It was pretty effective for covering a large area rapidly and shows the layout of the town quite well. The recon survey was followed with high-resolution (.25m transect spacing) resistance & mag gradient survey of smaller areas, and shovel testing of several suspected archaeological features. There is more information here

Additional results can be found here:

  • Cambria Plan (1.5 MB)

  • Geoff Jones
    Archeo-Physics, LLC


    Thank you for your very prompt reply. It's been a long time since you & I last spoke but I'll never forget the support you gave us back in 1997 when I was working on an offshore salvage expedition off the coast of South Carolina.

    We had rented a G-880 from another rental company & had a significant set up problem linking the laptop computer with our GPS system. When it was obvious that they could not fix the problem, we called your company & you spent a good solid two – three hours on the phone with us eventually solving the problem. We left the dock, sailed out, conducted our survey & located a totally untouched portion of the wreck we were working on which produced some extremely valuable & very rare pre Civil War era American Gold Eagle coins. The salvage was a complete success thanks in part to you and your tech support team. We can't thank you enough.

    I have forwarded the information that you sent to me to several of my colleagues so I'm sure they will be as impressed as I was on that 'Tulco Image'. Fantastic clarity! It seems that you have a winner with the 882. I have heard nothing but good things from several individuals who have used the unit and they all say it's the best they have ever worked with.

    Thanks again and hopefully our latest project venture will move forward. If so, I'm sure we will be contacting you.

    Billy Gill


    We were able to use MagPick’s pipeline method to compute the depth of a buried cable from data collected by two G-882 cesium sensors set up as a transverse gradiometer. Later, we were able to compare these results against the expected depth of the cable for over thirty kilometers of its route. Nearly all of the computed depths agreed with expected values.

    By the way, you should give Misha his own testimonial section. He was extremely helpful in teaching us how to process our gradiometer data with MagPick!

    Dan Ciarletta
    Alpine Ocean Seismic Survey Inc


    Ross,

    It was good to talk to you today. Thanks for the information on the G-882. I think at this time I will need to wait until at least the fall to think about getting a second G-882. I started in the 70's doing survey work and have used at least 5 different type magnetometers. The Geometrics G-882 is by far the best. On one job I did a few years ago, I was able to determine quarter gamma targets with the cesium magnetometer.

    In 1995 we used a Geometrics 866 proton magnetometer to locate the first submarine to sink a warship the H L Hunley (ca 1864); by 1997 we had moved up to the G-881 cesium magnetometer. We first used one on the National Underwater and Marine Agency (NUMA) search in Pass Cavallo Channel, Texas. Later we moved up to the G-882, when we needed (by contract) to keep the mag a given distance from the bottom. We were able to record the depth, produce a contour map to show we had met the contract altitude requirements and were able to detect quarter gamma targets. From what I have seen this is the best magnetometer available bar none.

    Ralph Wilbanks
    Diversified Wilbanks, Inc.
    NUMA Trustee


    Hello Ross,

    ...Geometrics has proven to be an outstanding company with very high quality products and service level. It’s very good value for money. I am very impressed and pleased with the results.

    Misha is doing an outstanding job. I am very pleased with him. He has a deep knowledge of the mag and related systems and has been able to train us very effectively. He his a great guy, enthusiastic and a very good teacher. Our expectations where exceeded by far.

    Best regards.
    Luis Sa Couto
    SubNauta


    The G-856 and G-858 magnetometers are an essential part of our site assessment toolbox. I just had the 858 out in blowing rain and snow yesterday at an old dump site.

    Randolph L. Brown
    L.G. Site Assessment Unit Chief
    Remedial Section
    Bureau of Environmental Remediation


    I would like to extend my thanks for all troubleshooting and start up help received, it has been a steep learning curve trying to get up to speed on an entirely new system and software, as well as attempting to nail down MagPick processing on the fly has been interesting to say the least. I appreciate all the support Geometrics has offered over this process of throw and go, trying to hit the ground running seldom works out as planned with new equipment and software in such a quick time frame, so you guys have been a huge help. We have been very impressed with the quality and accuracy of the data collected in an array of survey environments.

    Steve MacDonald
    Terrasond Ltd

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