Cathodic Protection Network Technotoy Stage 2

Real time recorded measurements of corrosion

reactions.

Technotoy first stage.

All meters operativeOscilloscopeRecording multimeterData loggerMicro-ammeterAlexander Cell in placeDry cell battery in place

Orac connected

Stage 2 Technotoy

The measurements• Oscilloscope will be used

to examine the so called ‘off potential’ measurement and see if it is really possible to identify the ‘polarized potential’.

• It will also be used with a probe to measure the pH if the electrolyte in a variety of places at various stages of all measurements as required by Pourbaix

Left hand meter• This has built in

memory of 40,000 measurements.

• It can measure temperature, volts, amps, resistance and capacitance.

• All stored data can be downloaded to a spread sheet after the tests.

The centre meter.• This is a multi-meter with a

RS232c (infra-red) connection to the computer USB

• It can measure volts, amps, resistance, heat, capacitance and frequency.

• It is connected between the breadboard zero rail and the Cu/CuSO4 electrode and can be used to probe the measurements made in field work that are replicated in Orac.

The right hand meter.• This meter will be used to

measure actual corrosion current.

• It will be connected to the anode and cathode of the Alexander Cell and provide the only path for the charges from the corrosion reaction.

• There is no other source of energy in the Alexander Cell.

Breadboard circuit

Orac circuit• The copper board is remote

earth with zero resistance.• The groundbed resistance is

replicated underneath.• Pipe-to-soil measurements can

be made at test posts, one of which is connected to the negative rail of the breadboard.

• Charges from the positive source are conducted through the yellow jumper to remote earth.

• The TR can be connected to the groundbed itself through a red wire that is not visible in this picture.

The spread sheet screenshot

Compare with spreadsheet

Picture of actual live spreadsheet

The goal• Data is put into the spreadsheet direct from the

instruments.• Formulae in each cell calculates the effects on the

charges as they pass through each conductive path.• Electronic components have specified values and

variable components will be seen to have variable effects on the data.

• The spreadsheet will display the effects of variations dynamically.

• Components can be built into the breadboard to trigger adjustments to the output controls of the energy source.

• This can be built to replicate any pipeline network.

Measurements 1• Photographing is difficult

because of reflections but you can see the time and date.

• The oscilloscope trace is straight line and the data log shows the voltage with the dry cell battery in it’s holder.

• The Alexander Cell is not active as the electrolyte sample is not bridging between the anode and cathode

Measurements 2• The left hand meter is

showing 1.3477 volts between the blue and green breadboard posts.

• The green post is connected to the zero rail of the breadboard circuit, this can be checked by referring to previous slides.

Measurements 3• In this picture you can see that

the centre meter is displaying the same as the computer log of the voltage of the dry cell battery.

• 1.329volts between the green breadboard post and the red post.

• The red post is not connected directly to a breadboard rail but used as a measuring node.

• It is connected to the Cu/CuSO4 electrode that is touching remote earth of Orac.

Measurement 4• The dry cell battery is in it’s

holder and charges resulting from this corrosion reaction are being drained from the negative rail of the lower grid of the breadboard through the blue jumper lead.

• The charges from the reaction are passing from the carbon rod inside the battery to the red rail of the breadboard.

• Red and black jumpers are connecting through the breadboard to the metering systems.

Circuit continuity

Breadboard details

Breadboard and Orac details

Electrolyte bridging Alexander Cell

Measurements 5• The Alexander Cell has been

activated by polishing the anode.

• 4.5 micro-amps are passing from the meter into the ground, remote earth, and back into the second base electro of the Alexander cell to complete it’s measuring circuit.

• The anode of the Alexander cell is connected to the first test post on the Orac pipeline.

• Test post 4 of the Orac pipeline is connected to the negative (zero) rail of the breadboard by the white jumper.

Measurements 6• The dry cell battery has

been disconnected.• The meter displays show

the equilibrium as the capacitance of the system discharges.

• The yellow jumper connects the groundbed remote earth to the positive rail of the breadboard and there is a capacitor built into Orac to show what is called polarisation decay,

Measurements 6

Measurements 7

Measurements 8

• The data logger is recording the decay over time.

• The time stamp shows camera time.

• The oscilloscope is recording the decay curve.

Measurement 9

Measurement 10

Oscilloscope display

Oscilloscope record.• This can be seen as a straight line but events ac be seen

when the battery was disconnected and when the scope probe was free.

• During much of my work I have seen corrosion noise and background electrical disturbances.

• The oscilloscope allows these to be examined by experimentation on the bench and in the field.

• I have found it impossible to see the ‘polarised potential’ kick as described by the scientists in the Hague. The closed circuit experiment that they conducted was with a controlled pH of the electrolyte in which there was a narrow band that could be measured at all.

Data to Excel

Voltages logged in Excel

• This is a selection from a period when the battery was removed from it’s folder and the capacitance of the system was decaying.

• It can be seen as a straight line, for this section, but the whole log was over a longer period and recorded voltages during many of the events.

We can now examine real data about corrosion cells.

• We have a few simple measurements of voltages and some measurements of corrosion current itself.

• We have a log of voltages over a short period of time and an oscilloscope image of electrons during a period of time.

• We have the ability to describe a real equivalent circuit and embed more features that we observe in field work.

• Software developers can now start to visualise how to use higher level coding to best represent this data on displays and for the computer to make real science-based calculations to analyse real cathodic protection systems.

Podemos agora examinar os dados reais sobre as células de corrosão. • Temos algumas medidas simples de tensões e algumas medições

da própria corrente de corrosão.

• Temos um registo das tensões ao longo de um período curto de uma imagem osciloscópio de electrões tempo e durante um período de tempo.

• Temos a capacidade para descrever um circuito equivalente real e incorporar mais recursos que observamos no trabalho de campo.

• Os desenvolvedores de software podem agora começar a visualizar como usar maior codificação nível para melhor representar esses dados em monitores e para o computador para fazer cálculos baseados na ciência reais para analisar sistemas reais de proteção catódica.

Thumb nail sketch of circuit

What is all this about?• Millions of voltage measurements are recorded and

represented in graphs.• People pretend that they can interpret these readings to

determine if corrosion has been controlled.• They even describe some values a s ‘protected’ and

investors believe that they have controlled corrosion.• Pipelines leak due to corrosion that is claimed to have

been controlled and everybody blames everybody else.• I am seeking to rationalize this situation using computer

power and the first job is to examine the credibility of the data input.

O que é tudo isso? • Milhões de medições de tensão são registrados e

representadas em gráficos.As pessoas fingem que eles podem interpretar estas leituras para determinar se a corrosão tem sido controlada.Eles ainda descrever alguns valores de S 'protegidas' e os investidores acreditam que eles têm controlado a corrosão.Pipelines vazar devido à corrosão que é reivindicado ter sido controlada e todos culpam todo mundo.Estou buscando racionalizar esta situação usando alimentação do computador e o primeiro trabalho é examinar a credibilidade da entrada de dados.

Thumb nail sketch 2

Observe the voltages and micro-amps

• 1.329 volts is seen on the data logger display from the RS232c connected to the centre meter. This meter is connected between the negative rail (zero) and the copper in the copper-sulphate solution.

• The Oscilloscope display can show the wave forms of each event.

• 1.3477 is the measurement of the dry cell battery through the conductive paths seen in the sketch.

• The porous plug of the Cu/CuSO4 electrode is in contact with the remote earth plate of Orac.

• The positive of the battery (corrosion cell) is connected to the active rail of the breadboard and through to Orac groundbed.

Thumb nail sketch 3

Observations • The data logger is recording 1.366 volts between

the Cu/CuSO4 electrode and the negative rail on the breadboard that is the zero of this circuit.

• The battery is discharging current into the system and 7.1 micro-amps are passing through the meter on the right. We do not know why.

• The left hand meter is displaying 1.3477 volts between the positive rail of the breadboard and the zero rail. The paths of these charges can be seen by following the black lines on the sketch.

Alexander Cell in circuit• The electrolyte sample is

bridging the anode and the cathode allowing current to flow through meter 3.

• The anode of this corrosion cell is connected to Orac test post.

• Orac pipeline 1 is connected through variable resistors to pipelines 2 and 3.

Under Orac

• The resistors in the pipelines underneath Orac can be used to simulate different lengths of steel pipelines buried between isolation joints.

System capacitance

• I have added random fixed capacitors that produce a ‘depolarisation time’ on the oscilloscope and the data logger.

• We find that the depolarisation of the Alexander Cell itself can be recorded when the cathodic protection is switched off.

• We find this feature in case studies of field work and need to model this on our computer.

Impressed cathodic protection measuring circuit

• The actual CP circuit can only be measured at nodes such as isolation joints and junction boxes.

Computable drawing

We can apply this data to our spreadsheet.

• We simply feed the data from the meters into the appropriate cells.

• This is all that is done by the instruments that are sold at present for CP work.

• They only display voltages in graphic form and do not analyse the cathodic protection circuit.

• We can apply Ohms and Kirchhoffs laws to our spreadsheet, as I have already done in the Dynamic Project itself.