You may be able to equal the results of the Disto-X2 with the new BRIC4, yet find it more useful because you don’t have to worry about the BRIC4 dying when it is accidentally dropped into a pool of water. See Aaron Bird’s evaluation (from the 2021 NSS Convention) of the BRIC4 as a cave survey device (he compares it to the Disto-X2).
https://www.youtube.com/watch?v=OCi35qMwDQI I’ve found the BRIC4 is relatively easy to calibrate compared to the Disto-X2, but it needs to be re-calibrated when you move to different locations due to local magnetic field changes. Fortunately it tells you (through it’s error message code) that’s the problem, and re-calibration is done internally on the device so you can do it prior to a day of cave survey. https://ngdc.noaa.gov/geomag/calculators/magcalc.shtml?#declination Diana ************************************************** Diana R. Tomchick Professor Departments of Biophysics and Biochemistry UT Southwestern Medical Center 5323 Harry Hines Blvd. Rm. ND10.214A Dallas, TX 75390-8816 diana.tomch...@utsouthwestern.edu<mailto:diana.tomch...@utsouthwestern.edu> (214) 645-6383 (phone) (214) 645-6353 (fax) On Feb 10, 2022, at 5:17 PM, Mark Minton <mamintonca...@gmail.com<mailto:mamintonca...@gmail.com>> wrote: EXTERNAL MAIL If your accuracy was less than 1%, I think you had a problem! ;-) Brunton accuracy was pretty good, but you can't beat properly calibrated Disto-X2s with front and backsights. I've done several surveys with less than 0.5% loop-closure error, and a couple of large loops (over 2000 feet) had 0.1% error! Mark Minton On Thu, Feb 10, 2022 at 5:58 PM Reddell, James R <jreddell.ca...@austin.utexas.edu<mailto:jreddell.ca...@austin.utexas.edu>> wrote: I mapped all of Caverns of Sonora up to the pit with a Brunton on a tripod and we consistently got less than 1% accuracy in short and long loops. I also got very good accuracy in some long surveys in Yucatan caves. James ________________________________ From: Texascavers <texascavers-boun...@texascavers.com<mailto:texascavers-boun...@texascavers.com>> on behalf of speodes...@gmail.com<mailto:speodes...@gmail.com> <speodes...@gmail.com<mailto:speodes...@gmail.com>> Sent: Thursday, February 10, 2022 4:40 PM To: texascavers@texascavers.com<mailto:texascavers@texascavers.com> <texascavers@texascavers.com<mailto:texascavers@texascavers.com>> Subject: Re: [Texascavers] Brunton Revisited Thanks for leveling with us, Dwight. Doing the inclinations was hard going handheld. All I ever owned were two Army Bruntons. Suuntos were a big change! And thanks to Carl for his good article. William R. (Bill) Elliott Sent from my iPhone On Feb 10, 2022, at 4:34 PM, Dwight Deal <dirt...@comcast.net<mailto:dirt...@comcast.net>> wrote: Carl Kunath wrote an excellent historical article on the use of the old Brunton compass in cave surveying. Unfortunately, the major source of error was not clearly noted. That error is not having the Brunton as near perfectly level as possible when you make the sighting. A tripod helps if you pay attention, but it is possible to make accurate sights hand-held as well. I taught Herb Conn how to survey with a Brunton in 1959, and in many miles of hand-held Jewel Cave survey loops our error was consistently on the order of ½ of 1%. Keeping it level was the key. Considerable contortions were sometimes required of the surveyor, however. DirtDoc CAUTION: This email originated from outside UTSW. Please be cautious of links or attachments, and validate the sender's email address before replying. _______________________________________________ Texascavers mailing list | http://texascavers.com Texascavers@texascavers.com<mailto:Texascavers@texascavers.com> | Archives: http://www.mail-archive.com/texascavers@texascavers.com/ http://lists.texascavers.com/listinfo/texascavers ________________________________ UT Southwestern Medical Center The future of medicine, today.
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