Patent ID: 6265880
Filing Date: 2001-07-24
Classification: G01R

Abstract:
A method for identifying chafing of a conduit using a medium, wherein said medium is selected from the group consisting of at least one of those mediums which are capable of supporting an electrical current and voltage, an electromagnetic signal, and an optical signal, comprising the steps of:placing at least one said medium along the length of said conduit, wherein said medium has a first end and a second end, said medium being placed such that a chafing object contacts said medium prior contacting said conduit;determining whether said chafing object has contacted said medium;locating the approximate point on said conduit where said medium is chafed;I. performing a first test sequence wherein said medium supports said electrical current and voltage and said electromagnetic signal, further comprising the steps of:attaching a first resistor of resistance value R.sub.B1 ohms between said first end and an electrical ground;attaching a second resistor of resistance value R.sub.B2 ohms between said second end and said electrical ground;wherein said resistance value R.sub.B1 ohms of said first resistor is equivalent to said resistance value R.sub.B2 ohms of said second resistor such thatR.sub.B1 =R.sub.B2 =R.sub.Bmeasuring a resistance from a point on said medium to said electrical ground;determining if said measured resistance is substantially equal to either R.sub.b /2 or not, the possibilities being:a. if said measured resistance substantially equals R.sub.B /2, then either:there is no chafing on said medium orchafing exists but has not caused said medium to short to said electrical ground;b. if said measured resistance does not substantially equal R.sub.B /2, then chafing exists on said medium;c. if said measured resistance substantially equals R.sub.B, then said medium is broken and the one of said first and said second end connected to said point is electrically floating;d. if said measured resistance substantially equals zero, then said medium is broken or chafed and either said break or said chafe on said medium is in contact with an electrically grounded member;choosing whether or not to repeat said step of measuring and said step of determining on an opposite point of said medium;if the choice is to repeat, then repeating said steps of measuring and determining;II. performing a second test sequence wherein said medium supports said electrical current and voltage and said electromagnetic signal, further comprising the steps of:accessing both said first and said second ends of said medium;measuring a resistance between said first and said second ends of said medium, where:a. if said measured resistance does not substantially equal R.sub.M, the total resistance of said medium, then said medium is broken;b. if said measured resistance substantially equals R.sub.M, then either:said medium is not broken orsaid medium is broken and both ends of a break are contacting a conducting member ORsaid medium is not broken but chafed by a non-conducting member or said conducting member;III. performing a third test sequence wherein said medium supports said electrical current and voltage and said electromagnetic signal, further comprising the steps of:attaching a first resistor of resistance value R.sub.B1 ohms between said first end of said medium and said electrical ground;attaching a second resistor of resistance value R.sub.B2 ohms between said second end of said medium and said electrical ground;wherein said said resistance value R.sub.B1 ohms of said first resistor is not equivalent to said resistance value R.sub.B2 ohms of said second resistor such thatR.sub.B1.noteq.R.sub.B2measuring a resistance from a point on said medium to said electrical ground;determining, from said step of measuring, where:a. if said resistance substantially equals R.sub.B1 R.sub.B2 /(R.sub.B1 +R.sub.B2), then either:there is no chafing on said medium orchafing, exists but has not caused said medium to short to said electrical ground;b. it said resistance does not substantially equal R.sub.B1 R.sub.B2 /(R.sub.B1 +R.sub.B2), then chafing exists on said medium;c. if said resistance substantially equals either R.sub.B1 or R.sub.B2, then said medium is broken and the one of said first and said second ends whose said attached resistor equals said resistance is electrically floating;d. if said resistance substantially equals zero, then said medium is broken or chafed and either said break or said chafe on said medium is in contact with said electrically grounded member;choosing whether or not to repeat said step of measuring and said step of determining on an opposite end of said medium; andif the choice is to repeat, then repeating said steps of measuring and determining.