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Author
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Topic: Plunging GSC
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wpd2688
Member
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posted 11-02-2005 11:37 AM
  
Lately in the tests I've run, after the first chart the GSC on my Stoelting CPS does not respond at all. I get a sloping line. What can I do to remedy this?IP: Logged |
sackett
Moderator
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posted 11-02-2005 12:04 PM
Does this happen after collecting appropriate GSC responses during the first test? Are you using plates or disposables?Jim IP: Logged |
wpd2688
Member
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posted 11-02-2005 12:13 PM
i'm using disposables. It happens after collecting the first chart. The data for the GSC is good on the first chart, then it drops on the 2nd and 3rd. IP: Logged |
sackett
Moderator
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posted 11-02-2005 03:29 PM
If you get acceptable reactions on your first chart then nothing but a plunging GSR or GSC, it sounds like a cold (or cooling) hand. Try either warming up the test area/room or your examinee's hand with a scarf (or the like). Disposables are less succeptable to CM's by pressure than plates are so you don't have to worry about not being able to see the electrodes. Or, reposition the electrodes to the palm of the hand, I seem to get better reactions there than on cold or really dry fingers. Jim
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J.B. McCloughan
Member
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posted 11-03-2005 08:40 AM
In addition to the previous suggestions and to expound on Sackett’s suggestion, a plunging EDA can also be related to a bad or loss of contact. Check your leads and contacts(snaps). If they both appear to be in order, I would suspect that either the disposable tabs are not properly adhering or the examinee is causing the problem by tampering with the connection (pressing his fingers down or readjusting the tabs). I suggest keeping a roll of surgical type tape on hand. This can be used to aid with adhesion, as the tabs do not always stick properly on someone who is significantly sweating.If the plunging EDA is a consistent and significant plunging with an equal rise in tracing, the EDA component in the instrument could be malfunctioning. Just some of my ideas from anecdotal experiences. I am interested to find out what you discover to be the cause in your trouble shooting. What were the minimum, maximum, and average ohms readings on the examinations you had the plunging EDA. [This message has been edited by J.B. McCloughan (edited 11-03-2005).] IP: Logged |
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