Pham Huy Dung on May 15 at 3:28 AM: Could you help me in this issue: Which standard specifies how to calculate the average current density as in the formula below ? J’o = [Jo + (T – 25oC)].[(v-2)*10%+1] 5:59 AM Roger Alexander sent the following messages at 6:30 AM Do not be fooled by this mention of current density, it is a smoke screen. Current density is supposed to be the amount of current passing through a given area of metal at the interface with the electrolyte. This concept begs the question 'how do we know the surface area exposed?' Coating faults are accurately located by DCVG (that I invented ) but the surface area exposed can be anodic or cathodic. CP current will pass readily into the cathodic area but will be resisted by the corrosion current emitting from the anodic area. I suggest you study our on line course that is based on real science and actual experience in the field. ... http://www.pipeline-corrosion-control.com/CorrespondenceCourse/ welcome to Cathodic Protection Network technology....... real science ... not bullshit 6:32 AM Pham Huy Dung sent the following message at 6:37 AM View Pham’s profile Pham Huy Dung Thanks 6:37 AM Roger Alexander sent the following messages at 6:41 AM this link will help you as the Alexander Cell is the only method to actually measure current density because it has a measurable surface area of anode and cathode http://www.pipeline-corrosion-control.com/alcemake/ 6:41 AM Pham Huy Dung sent the following message at 6:43 AM View Pham’s profile Pham Huy Dung Thank you so much 6:43 AM Roger Alexander sent the following messages at 6:45 AM http://www.pipeline-corrosion-control.com/disbondment/CPshielding3.htm there is much more and you are the first in Vietnam 6:46 AM Pham Huy Dung sent the following messages at 6:48 AM View Pham’s profile Pham Huy Dung I am designing for internal cathodic protection for cooling pipe and water box View Pham’s profile Pham Huy Dung have you ever done like this? View Pham’s profile Pham Huy Dung When i calculate the average current density follow this formula the Owner ask the reference standard? View Pham’s profile Pham Huy Dung i have found some standard like EN 12499, BS 7361, SP0169 but can not have infor 6:52 AM Roger Alexander sent the following messages at 7:10 AM I have seen some internal CP systems in an atomic power station and they failed to deliver their designed results. I looked at the specifications and drawings (including asbuilt) but they were all unsoundly based. These included monitoring by 'resistance loops' which did not render accurate information. I know the company and the individual who designed this system and the company that installed it. They were 'old school' established specialists who did not even understand Gibbs Free Energy or the effect this has on the Nernst equations. My own opinion is that internal cathodic protection of pipes might only be possible using strip anodes such as those that are like wires coated in conductive plastic. Raychem are one of the manufacturers but I believe there are others in China. you have not said if the structure is internally coated or the coating specification remember that electrical charges take the least line of resistance to complete their circuit Kirchhoffs laws that is why sacrificial anodes are always installed with an insulating 'mat' to spread the charges 7:16 AM Pham Huy Dung sent the following message at 7:23 AM View Pham’s profile Pham Huy Dung the structure is coated with 2 epoxy coating layers about 500 microns 7:23 AM Roger Alexander sent the following messages at 8:07 AM Then you must test the circuit resistance between your anode and the subject metal. There is no way to calculate this as we cannot possible inspect the internal coating accurately. No cathodic protection system can be designed by theory as there are too many variables. it is unlikely that you can use pigs to acquire data 8:10 AM Fri Pham Huy Dung sent the following messages at 6:58 AM View Pham’s profile Pham Huy Dung I have one thing that want to ask you View Pham’s profile Pham Huy Dung Do you know the current density of impress current in the fresh water with the resistivity about 44 ohm.m 7:02 AM Roger Alexander sent the following message at 11:41 AM This is not a technical or scientific question. Fresh water? Resistivity of about 44 ohm.m? What sort of instrments are used to gather such dataand what is the specific procedure? Please understand real science and not bullshit put out by NACE and ICorr. Refer to proper research establishments that are party to real science such as Cerne LHC and real scientists such as Eisten and Hawking. 11:41 AM Pham Huy Dung sent the following messages at 12:20 PM View Pham’s profile Pham Huy Dung Fresh water is river water View Pham’s profile Pham Huy Dung The conductivity is 223 microSiemen, so the resistivity is calculated to about 44 ohm.m View Pham’s profile Pham Huy Dung I took the data from customer View Pham’s profile Pham Huy Dung Is there any standard related to current density like iso 15589, DNV B401 for freshwater? View Pham’s profile Pham Huy Dung Iso 15589 for soil, dnv b401 for sea water 12:25 PM Sun Roger Alexander sent the following message at 7:26 PM describe current density please. 7:26 PM Pham Huy Dung sent the following message at 10:13 PM View Pham’s profile Pham Huy Dung I choose current density is 10 mA/m2 10:13 PM Today Roger Alexander sent the following message at 12:29 AM how do you measure this? 12:29 AM Pham Huy Dung sent the following messages at 12:36 AM View Pham’s profile Pham Huy Dung I follow one document that they give this value View Pham’s profile Pham Huy Dung I choose this value for my design 12:36 AM Read Pham Huy Dung Pham Huy Dung on May 15 at 3:28 AM: Could you help me in this issue: Which standard specifies how to calculate the average current density as in the formula below ? J’o = [Jo + (T – 25oC)].[(v-2)*10%+1] 5:59 AM Roger Alexander sent the following messages at 6:30 AM Do not be fooled by this mention of current density, it is a smoke screen. Current density is supposed to be the amount of current passing through a given area of metal at the interface with the electrolyte. This concept begs the question 'how do we know the surface area exposed?' Coating faults are accurately located by DCVG (that I invented ) but the surface area exposed can be anodic or cathodic. CP current will pass readily into the cathodic area but will be resisted by the corrosion current emitting from the anodic area. I suggest you study our on line course that is based on real science and actual experience in the field. ... http://www.pipeline-corrosion-control.com/CorrespondenceCourse/ welcome to Cathodic Protection Network technology....... real science ... not bullshit 6:32 AM Pham Huy Dung sent the following message at 6:37 AM View Pham’s profile Pham Huy Dung Thanks 6:37 AM Roger Alexander sent the following messages at 6:41 AM this link will help you as the Alexander Cell is the only method to actually measure current density because it has a measurable surface area of anode and cathode http://www.pipeline-corrosion-control.com/alcemake/ 6:41 AM Pham Huy Dung sent the following message at 6:43 AM View Pham’s profile Pham Huy Dung Thank you so much 6:43 AM Roger Alexander sent the following messages at 6:45 AM http://www.pipeline-corrosion-control.com/disbondment/CPshielding3.htm there is much more and you are the first in Vietnam 6:46 AM Pham Huy Dung sent the following messages at 6:48 AM View Pham’s profile Pham Huy Dung I am designing for internal cathodic protection for cooling pipe and water box View Pham’s profile Pham Huy Dung have you ever done like this? View Pham’s profile Pham Huy Dung When i calculate the average current density follow this formula the Owner ask the reference standard? View Pham’s profile Pham Huy Dung i have found some standard like EN 12499, BS 7361, SP0169 but can not have infor 6:52 AM Roger Alexander sent the following messages at 7:10 AM I have seen some internal CP systems in an atomic power station and they failed to deliver their designed results. I looked at the specifications and drawings (including asbuilt) but they were all unsoundly based. These included monitoring by 'resistance loops' which did not render accurate information. I know the company and the individual who designed this system and the company that installed it. They were 'old school' established specialists who did not even understand Gibbs Free Energy or the effect this has on the Nernst equations. My own opinion is that internal cathodic protection of pipes might only be possible using strip anodes such as those that are like wires coated in conductive plastic. Raychem are one of the manufacturers but I believe there are others in China. you have not said if the structure is internally coated or the coating specification remember that electrical charges take the least line of resistance to complete their circuit Kirchhoffs laws that is why sacrificial anodes are always installed with an insulating 'mat' to spread the charges 7:16 AM Pham Huy Dung sent the following message at 7:23 AM View Pham’s profile Pham Huy Dung the structure is coated with 2 epoxy coating layers about 500 microns 7:23 AM Roger Alexander sent the following messages at 8:07 AM Then you must test the circuit resistance between your anode and the subject metal. There is no way to calculate this as we cannot possible inspect the internal coating accurately. No cathodic protection system can be designed by theory as there are too many variables. it is unlikely that you can use pigs to acquire data 8:10 AM Fri Pham Huy Dung sent the following messages at 6:58 AM View Pham’s profile Pham Huy Dung I have one thing that want to ask you View Pham’s profile Pham Huy Dung Do you know the current density of impress current in the fresh water with the resistivity about 44 ohm.m 7:02 AM Roger Alexander sent the following message at 11:41 AM This is not a technical or scientific question. Fresh water? Resistivity of about 44 ohm.m? What sort of instrments are used to gather such dataand what is the specific procedure? Please understand real science and not bullshit put out by NACE and ICorr. Refer to proper research establishments that are party to real science such as Cerne LHC and real scientists such as Eisten and Hawking. 11:41 AM Pham Huy Dung sent the following messages at 12:20 PM View Pham’s profile Pham Huy Dung Fresh water is river water View Pham’s profile Pham Huy Dung The conductivity is 223 microSiemen, so the resistivity is calculated to about 44 ohm.m View Pham’s profile Pham Huy Dung I took the data from customer View Pham’s profile Pham Huy Dung Is there any standard related to current density like iso 15589, DNV B401 for freshwater? View Pham’s profile Pham Huy Dung Iso 15589 for soil, dnv b401 for sea water 12:25 PM Sun Roger Alexander sent the following message at 7:26 PM describe current density please. 7:26 PM Pham Huy Dung sent the following message at 10:13 PM View Pham’s profile Pham Huy Dung I choose current density is 10 mA/m2 10:13 PM Today Roger Alexander sent the following message at 12:29 AM how do you measure this? 12:29 AM Pham Huy Dung sent the following messages at 12:36 AM View Pham’s profile Pham Huy Dung I follow one document that they give this value View Pham’s profile Pham Huy Dung I choose this value for my design 12:36 AM Read Pham Huy Dung Pham Huy Dung on May 15 at 3:28 AM: Could you help me in this issue: Which standard specifies how to calculate the average current density as in the formula below ? J’o = [Jo + (T – 25oC)].[(v-2)*10%+1] 5:59 AM Roger Alexander sent the following messages at 6:30 AM Do not be fooled by this mention of current density, it is a smoke screen. Current density is supposed to be the amount of current passing through a given area of metal at the interface with the electrolyte. This concept begs the question 'how do we know the surface area exposed?' Coating faults are accurately located by DCVG (that I invented ) but the surface area exposed can be anodic or cathodic. CP current will pass readily into the cathodic area but will be resisted by the corrosion current emitting from the anodic area. I suggest you study our on line course that is based on real science and actual experience in the field. ... http://www.pipeline-corrosion-control.com/CorrespondenceCourse/ welcome to Cathodic Protection Network technology....... real science ... not bullshit 6:32 AM Pham Huy Dung sent the following message at 6:37 AM View Pham’s profile Pham Huy Dung Thanks 6:37 AM Roger Alexander sent the following messages at 6:41 AM this link will help you as the Alexander Cell is the only method to actually measure current density because it has a measurable surface area of anode and cathode http://www.pipeline-corrosion-control.com/alcemake/ 6:41 AM Pham Huy Dung sent the following message at 6:43 AM View Pham’s profile Pham Huy Dung Thank you so much 6:43 AM Roger Alexander sent the following messages at 6:45 AM http://www.pipeline-corrosion-control.com/disbondment/CPshielding3.htm there is much more and you are the first in Vietnam 6:46 AM Pham Huy Dung sent the following messages at 6:48 AM View Pham’s profile Pham Huy Dung I am designing for internal cathodic protection for cooling pipe and water box View Pham’s profile Pham Huy Dung have you ever done like this? View Pham’s profile Pham Huy Dung When i calculate the average current density follow this formula the Owner ask the reference standard? View Pham’s profile Pham Huy Dung i have found some standard like EN 12499, BS 7361, SP0169 but can not have infor 6:52 AM Roger Alexander sent the following messages at 7:10 AM I have seen some internal CP systems in an atomic power station and they failed to deliver their designed results. I looked at the specifications and drawings (including asbuilt) but they were all unsoundly based. These included monitoring by 'resistance loops' which did not render accurate information. I know the company and the individual who designed this system and the company that installed it. They were 'old school' established specialists who did not even understand Gibbs Free Energy or the effect this has on the Nernst equations. My own opinion is that internal cathodic protection of pipes might only be possible using strip anodes such as those that are like wires coated in conductive plastic. Raychem are one of the manufacturers but I believe there are others in China. you have not said if the structure is internally coated or the coating specification remember that electrical charges take the least line of resistance to complete their circuit Kirchhoffs laws that is why sacrificial anodes are always installed with an insulating 'mat' to spread the charges 7:16 AM Pham Huy Dung sent the following message at 7:23 AM View Pham’s profile Pham Huy Dung the structure is coated with 2 epoxy coating layers about 500 microns 7:23 AM Roger Alexander sent the following messages at 8:07 AM Then you must test the circuit resistance between your anode and the subject metal. There is no way to calculate this as we cannot possible inspect the internal coating accurately. No cathodic protection system can be designed by theory as there are too many variables. it is unlikely that you can use pigs to acquire data 8:10 AM Fri Pham Huy Dung sent the following messages at 6:58 AM View Pham’s profile Pham Huy Dung I have one thing that want to ask you View Pham’s profile Pham Huy Dung Do you know the current density of impress current in the fresh water with the resistivity about 44 ohm.m 7:02 AM Roger Alexander sent the following message at 11:41 AM This is not a technical or scientific question. Fresh water? Resistivity of about 44 ohm.m? What sort of instrments are used to gather such dataand what is the specific procedure? Please understand real science and not bullshit put out by NACE and ICorr. Refer to proper research establishments that are party to real science such as Cerne LHC and real scientists such as Eisten and Hawking. 11:41 AM Pham Huy Dung sent the following messages at 12:20 PM View Pham’s profile Pham Huy Dung Fresh water is river water View Pham’s profile Pham Huy Dung The conductivity is 223 microSiemen, so the resistivity is calculated to about 44 ohm.m View Pham’s profile Pham Huy Dung I took the data from customer View Pham’s profile Pham Huy Dung Is there any standard related to current density like iso 15589, DNV B401 for freshwater? View Pham’s profile Pham Huy Dung Iso 15589 for soil, dnv b401 for sea water 12:25 PM Sun Roger Alexander sent the following message at 7:26 PM describe current density please. 7:26 PM Pham Huy Dung sent the following message at 10:13 PM View Pham’s profile Pham Huy Dung I choose current density is 10 mA/m2 10:13 PM Today Roger Alexander sent the following message at 12:29 AM how do you measure this? 12:29 AM Pham Huy Dung sent the following messages at 12:36 AM View Pham’s profile Pham Huy Dung I follow one document that they give this value View Pham’s profile Pham Huy Dung I choose this value for my design 12:36 AM Read Pham Huy Dung Read Pham Huy Dung Roger Alexander sent the following messages at 9:14 AM This discussion is very interesting to me and very important to science as it is an example of misinformation and the corruption of science. It would be useful if you can gather all your references so that each one can be scrutinised to see if they are all soundly based on repeated observations and analysis of real data. I will now prepare a full examination of the words 'current density' because 'current' is the passage of electrical energy and 'density' is a quantitative quality relating to volume. 10ma/m2 is an expression of the amount of current passing through a SQUARE meter, and that is a measurement of area that begs the question 'how do you measure this value?' If we cannot measure current density then any discussion is not soundly based.