James,
I can discuss this with you if you wish to speak directly with the
manufacturer. But basically it is almost impossible to quantify the effects
of metal due to (1) the type of metal, (2) the amount and (3) the location.
All these factors affect distortion in different ways. Indeed DC trackers
are less susceptible to distortion since we are able to take the sample
measurements in between cycles at a point where the eddy currents have or
are decaying (so remember, the lower the measurement rates you use, the
better results you will have if there is metal present). If you can let me
know a bit more about your testing device, we can try to help.
Greg Erdmann
-----Original Message-----
From: Biomechanics and Movement Science listserver
[mailto:BIOMCH-L@NIC.SURFNET.NL]On Behalf Of James L. Metzler
Sent: Monday, November 05, 2001 12:10 PM
To: BIOMCH-L@NIC.SURFNET.NL
Subject: [BIOMCH-L] ASCENSION TECHNOLOGY CORP "Flock of Birds"
I am presently researching on the performance of 'Flock
of Birds' which is manufactured by Ascension Tech Corp.
Flock of Birds is a magnetic orientation device.
Specifically on how performance is degraded by using a
metal testing device within the magnetic field. Also comments
on AC or DC Pulsed magentic transmitters would be helpful.
I understand that on metal devices, eddy currents may be produced
on the surface of the device and DC Pulsed may perform better.
Any comments would be greatly appreciated.
James Metzler
The Pennsylvania State University
Biomechanics Laboratory
39 Rec Bldg
University Park, Pa 16802
Office: 814-863-1648
Email: jlm55@psu.edu
www.psu.edu/dept/biomechanics
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I can discuss this with you if you wish to speak directly with the
manufacturer. But basically it is almost impossible to quantify the effects
of metal due to (1) the type of metal, (2) the amount and (3) the location.
All these factors affect distortion in different ways. Indeed DC trackers
are less susceptible to distortion since we are able to take the sample
measurements in between cycles at a point where the eddy currents have or
are decaying (so remember, the lower the measurement rates you use, the
better results you will have if there is metal present). If you can let me
know a bit more about your testing device, we can try to help.
Greg Erdmann
-----Original Message-----
From: Biomechanics and Movement Science listserver
[mailto:BIOMCH-L@NIC.SURFNET.NL]On Behalf Of James L. Metzler
Sent: Monday, November 05, 2001 12:10 PM
To: BIOMCH-L@NIC.SURFNET.NL
Subject: [BIOMCH-L] ASCENSION TECHNOLOGY CORP "Flock of Birds"
I am presently researching on the performance of 'Flock
of Birds' which is manufactured by Ascension Tech Corp.
Flock of Birds is a magnetic orientation device.
Specifically on how performance is degraded by using a
metal testing device within the magnetic field. Also comments
on AC or DC Pulsed magentic transmitters would be helpful.
I understand that on metal devices, eddy currents may be produced
on the surface of the device and DC Pulsed may perform better.
Any comments would be greatly appreciated.
James Metzler
The Pennsylvania State University
Biomechanics Laboratory
39 Rec Bldg
University Park, Pa 16802
Office: 814-863-1648
Email: jlm55@psu.edu
www.psu.edu/dept/biomechanics
---------------------------------------------------------------
To unsubscribe send SIGNOFF BIOMCH-L to LISTSERV@nic.surfnet.nl
For information and archives: http://isb.ri.ccf.org/biomch-l
---------------------------------------------------------------
---------------------------------------------------------------
To unsubscribe send SIGNOFF BIOMCH-L to LISTSERV@nic.surfnet.nl
For information and archives: http://isb.ri.ccf.org/biomch-l
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