Radiologic Equipment and Maintenance Overview

X-ray Machine

Converts electric energy into electromagnetic energy.

Electrostatics

Study of stationary electric charges.

Electrodynamics

Study of electric charges in motion.

Electrification

Process of electrifying through contact, friction, induction.

Electric Charge

Fundamental unit is the coulomb (C).

Coulomb (C)

1C equals 6.3×10^18 electron charges.

mAs

Measure of electric charge in amperes per second.

Electrostatic Force

Like charges repel; unlike charges attract.

Electric Charge Distribution

Charge is concentrated on sharp surface curvatures.

Coulomb's Law

Force proportional to product of charges, inversely distance squared.

Electric Potential

Potential energy per unit charge, measured in volts.

Volt (V)

1 Volt equals 1 Joule per Coulomb.

Electric Current

Flow of electric charge, opposite to electron flow.

Conductor

Material allowing easy electron flow, e.g., copper.

Insulator

Material that does not allow electron flow, e.g., rubber.

Semiconductor

Material behaving as insulator or conductor under conditions.

Superconductor

Material with no resistance below critical temperature.

Electric Circuit

Closed path for controlled electric current.

Electric Resistance

Opposition to electric current flow.

Electric Potential Energy

Energy stored due to position of electric charges.

Electric Field

Region around charged objects affecting other charges.

Electrostatic Repulsion

Similar charges push away from each other.

Electric Charge Magnitude

Protons and electrons have equal but opposite charges.

Electric Potential

Measured in volts; energy per unit charge.

Volt (V)

Unit of electric potential; 1 J/C.

Potential Energy

Energy stored due to position; measured in joules.

Electric Current

Flow of electric charge; opposite to electron flow.

Conductor

Material allowing easy electron flow; e.g., copper.

Insulator

Material preventing electron flow; e.g., rubber.

Semiconductor

Material acting as conductor or insulator under conditions.

Ohm's Law

V = I × R; relationship of voltage, current, resistance.

Series Circuit

Circuit elements connected in a single path.

Parallel Circuit

Circuit elements connected across common points.

Electric Power

Rate of doing work; P = V × I.

Watt (W)

Unit of power; 1 A at 1 V.

Magnetism

Property of matter related to magnetic fields.

Magnetic Field

Area around a magnet where magnetic forces act.

Magnetic Moment

Dipole created by spinning charged particles.

Magnetic Domain

Region with aligned atomic magnetic dipoles.

Magnetic Permeability

Material's ability to conduct magnetic field lines.

Natural Magnet

Magnet occurring in nature; e.g., Earth.

Permanent Magnet

Magnet made from ferromagnetic material in strong field.

Electromagnet

Magnet created by electric current in wire.

Resistance (Ω)

Opposition to current flow in a conductor.

Current (A)

Flow rate of electric charge; measured in amperes.

Electric Current

Flow of electric charge through a conductor.

Magnetic Field

Region around a magnet where magnetic forces act.

North Pole

One of the two ends of a magnet.

South Pole

The opposite end of a magnet from the North Pole.

Magnetism Reduction

Decreased magnetism from hitting or heating a magnet.

Magnetic Repulsion

Same poles of magnets push each other away.

Magnetic Attraction

Opposite poles of magnets pull each other together.

Magnetic Force Formula

Force is proportional to pole strength over distance squared.

Tesla (T)

SI unit for measuring magnetic field strength.

Gauss (G)

Old unit for measuring magnetic field strength.

1 Tesla

Equal to 10,000 Gauss.

Earth's Magnetic Field

Approximately 50 micro Tesla at core.

MRI System Strength

Can reach up to 3 Tesla.

Luigi Galvani

Observed frog leg twitching with metal contact.

Alessandro Volta

Invented the first battery using zinc-copper plates.

Hans Christian Oersted

Showed current through wire produces magnetism.

Michael Faraday

Demonstrated moving magnetic fields generate electric current.

Heinrich Lenz

Established electricity and magnetism produce each other.

Electromagnetic Induction

Current induced by changing magnetic field in circuit.

Electric Motor

Converts electrical energy into mechanical energy.

Electric Generator

Converts mechanical energy into electrical energy.

Induction Motor

Type of motor used in x-ray tubes.

Transformer Function

Transforms electric potential and current intensity.

Transformer Law

Voltage change proportional to turns ratio of coils.

Step-Up Transformer

Increases voltage; turns ratio greater than one.

Step-Down Transformer

Decreases voltage; turns ratio less than one.

Closed-Core Transformer

Laminated iron layers reduce energy losses.

Shell-Type Transformer

More efficient; confines magnetic field lines better.

Autotransformer

Single winding acts as both primary and secondary.

Operating Console

Controls x-ray tube current and voltage settings.

Line Compensator

Adjusts voltage to 220 V for x-ray system.

Radiation Quality

Penetrability of x-ray beam, expressed in kVp.

Radiation Quantity

Number of x-rays or beam intensity, in mG.

Autotransformer

Supplies precise voltage to x-ray circuits.

Exposure Timers

Terminate exposure after approximately 6 seconds.

Synchronous Timers

Runs at 60 rpm, uses electric motor.

Electronic Timers

Accurate to 1 ms, controlled by microprocessor.

mAs Timers

Monitors product of mA and exposure time.