CATHODIC PROTECTION TESTER 1
(CBT STUDY GUIDE)
Electrons7are7particles7of7an7atom7that7carry7a?7-7ans--Negative7charge
________7is7an7electromotive7force7or7a7difference7in7potential7expressed7in7volts7-
7ans--Voltage
emf7=7-7ans--electromotive7force
E7=7-7ans--Voltage7rise7across7the7voltage7source7of7electrical7energy.
(battery,7pipe7to7soil7potential)
V7=7-7ans--Voltage7drop7across7a7sink7of7electrical7energy7(resistor)
__________7Is7the7flow7of7charges7along7a7conducting7path7and7is7measured7in7amper
es7-7ans--Current7(I)
What7are7the7symbols7used7for7current?7-7ans--
I7(any7unit7of7current)7,7A7(ampere7or7amps),7mA7(Milliamps)7,7μA7(Microamps)
_________7flows7constantly7in7one7direction7in7a7current7-7ans--Direct7current7(DC)
____________7regularly7reverses7direction7of7flow,71007or71207times7per7second.7-
7ans--Alternating7current7(AC)
________7is7a7relationship7between7the7ratio7of7voltage7to7current7and7resistance7of7a7c
ircuit7-7ans--Ohms7law
_______7is7the7rate7at7which7energy7is7used7by7an7electrical7device7-7ans--Power
Power7is7measured7in7what?7-7ans--Watts7(W)
Equation7for7power7=7-7ans--
P(power7in7watts)7=7E(voltage7in7volts)7X7I(current7in7amps)7or7I(current)^27X7R7(resista
nce)
This7law7states7that7the7sum7of7Source7voltages7around7in7a7closed7loop7of7a7series7cir
cuit7is7equal7to7the7sum7of7the7voltage7across7the7resistance7is7in7that7loop7-7ans--
Voltage7Law
, In7series7circuits7what7must7happen?7-7ans--Voltage7must7be7the7same7
Resistor7some7should7add7up7to7equal7total7voltage
This7law7states7that7as7much7current7flows7away7from7a7point7as7towards7it7-7ans--
Current7law
The7three7rules7for7a7parallel7circuit7-7ans--
Voltage7drop7crossed7each7branch7is7the7same7and7is7equal7to7the7source7voltage.7Tot
al7current7flowing7into7and7out7of7the7junction7point7of7the7branches7equals7the7sum7of7t
he7branches7currents.7The7total7equivalent7resistance7is7always7less7than7the7smallest7r
esistance7in7the7current.
_________7Maybe7used7to7increase7or7decrease7voltage7or7to7isolate7an7incoming7volt
age7source7from7the7outgoing7voltage.7-7ans--Transformer
The7transformer7has7a7limited7iron7core7with7two7sets7of7windings7these7are7called?7-
7ans--Primary7and7secondary
The7primary7winding7is7connected7to7the?7-7ans--Voltage7source
The7secondary7winding7is7connected7to?7-7ans--
The7unit7to7which7voltage7is7to7be7supplied
Where7are7taps7located?7-7ans--
In7the7secondary7winding7so7that7several7voltage7adjustments7are7possible
________7is7the7total7opposition7that7a7current7presents7to7an7alternating7current,7simila
r7to7resistance7in7the7direct7current7circle.7-7ans--Impedance
impedance7symbol7-7ans--Z
An7instrument7that7has7a7needle7that7rotates7across7the7meter7face7and7indicates7the7r
eading7on7a7scale?7-7ans--Analog7meter
Hybrid7meters7that7are7electronic7with7analog7displays7(electronic7amplifiers7driving7in7e
lectro7mechanical7coil)7or7sometimes7referred7to7as?7-7ans--Electronic7meters
When7using7an7analog7meter7the7reference7electrode7is7connected7to7which7terminal7to
7obtain7an7upscale7reading?7-7ans--Positive7terminal
For7low7voltage7ranges7the7circuit7resistance7becomes7more7sensitive7an7external7resis
tance7to7such7as7those7associated7with7test7leads7in7reference7electrode7to7electrolyte7
contact7me7causing7air7in7the7reading7-7ans--Voltmeters
Voltmeter7ranges7in7DC7-7ans--2007millivolts7=7current7shunt7readings
27volts7=7structure7to7electrolyte7potential
(CBT STUDY GUIDE)
Electrons7are7particles7of7an7atom7that7carry7a?7-7ans--Negative7charge
________7is7an7electromotive7force7or7a7difference7in7potential7expressed7in7volts7-
7ans--Voltage
emf7=7-7ans--electromotive7force
E7=7-7ans--Voltage7rise7across7the7voltage7source7of7electrical7energy.
(battery,7pipe7to7soil7potential)
V7=7-7ans--Voltage7drop7across7a7sink7of7electrical7energy7(resistor)
__________7Is7the7flow7of7charges7along7a7conducting7path7and7is7measured7in7amper
es7-7ans--Current7(I)
What7are7the7symbols7used7for7current?7-7ans--
I7(any7unit7of7current)7,7A7(ampere7or7amps),7mA7(Milliamps)7,7μA7(Microamps)
_________7flows7constantly7in7one7direction7in7a7current7-7ans--Direct7current7(DC)
____________7regularly7reverses7direction7of7flow,71007or71207times7per7second.7-
7ans--Alternating7current7(AC)
________7is7a7relationship7between7the7ratio7of7voltage7to7current7and7resistance7of7a7c
ircuit7-7ans--Ohms7law
_______7is7the7rate7at7which7energy7is7used7by7an7electrical7device7-7ans--Power
Power7is7measured7in7what?7-7ans--Watts7(W)
Equation7for7power7=7-7ans--
P(power7in7watts)7=7E(voltage7in7volts)7X7I(current7in7amps)7or7I(current)^27X7R7(resista
nce)
This7law7states7that7the7sum7of7Source7voltages7around7in7a7closed7loop7of7a7series7cir
cuit7is7equal7to7the7sum7of7the7voltage7across7the7resistance7is7in7that7loop7-7ans--
Voltage7Law
, In7series7circuits7what7must7happen?7-7ans--Voltage7must7be7the7same7
Resistor7some7should7add7up7to7equal7total7voltage
This7law7states7that7as7much7current7flows7away7from7a7point7as7towards7it7-7ans--
Current7law
The7three7rules7for7a7parallel7circuit7-7ans--
Voltage7drop7crossed7each7branch7is7the7same7and7is7equal7to7the7source7voltage.7Tot
al7current7flowing7into7and7out7of7the7junction7point7of7the7branches7equals7the7sum7of7t
he7branches7currents.7The7total7equivalent7resistance7is7always7less7than7the7smallest7r
esistance7in7the7current.
_________7Maybe7used7to7increase7or7decrease7voltage7or7to7isolate7an7incoming7volt
age7source7from7the7outgoing7voltage.7-7ans--Transformer
The7transformer7has7a7limited7iron7core7with7two7sets7of7windings7these7are7called?7-
7ans--Primary7and7secondary
The7primary7winding7is7connected7to7the?7-7ans--Voltage7source
The7secondary7winding7is7connected7to?7-7ans--
The7unit7to7which7voltage7is7to7be7supplied
Where7are7taps7located?7-7ans--
In7the7secondary7winding7so7that7several7voltage7adjustments7are7possible
________7is7the7total7opposition7that7a7current7presents7to7an7alternating7current,7simila
r7to7resistance7in7the7direct7current7circle.7-7ans--Impedance
impedance7symbol7-7ans--Z
An7instrument7that7has7a7needle7that7rotates7across7the7meter7face7and7indicates7the7r
eading7on7a7scale?7-7ans--Analog7meter
Hybrid7meters7that7are7electronic7with7analog7displays7(electronic7amplifiers7driving7in7e
lectro7mechanical7coil)7or7sometimes7referred7to7as?7-7ans--Electronic7meters
When7using7an7analog7meter7the7reference7electrode7is7connected7to7which7terminal7to
7obtain7an7upscale7reading?7-7ans--Positive7terminal
For7low7voltage7ranges7the7circuit7resistance7becomes7more7sensitive7an7external7resis
tance7to7such7as7those7associated7with7test7leads7in7reference7electrode7to7electrolyte7
contact7me7causing7air7in7the7reading7-7ans--Voltmeters
Voltmeter7ranges7in7DC7-7ans--2007millivolts7=7current7shunt7readings
27volts7=7structure7to7electrolyte7potential
