Essentia / Devices / X-ray

Device Lab 68

X-ray

A floor-mounted tube column on a rail, a high-frequency generator in a cabinet, a table with a floating top and a Bucky tray under it, an erect stand against the wall, and a control console behind lead glass. In the tray, in front of the digital detector, sit a twelve-to-one focused grid and three ionisation chambers.

Also called: X-Ray Machine, Radiography, X Ray. Arabic: جهاز الأشعة السينية. Device Lab 68 of 69 in BMEssentia Medical City, 2 configurations.

Overview: the configurations

How it works: the main parts

What each part does, from the X-ray lessons in the 3D Device Lab.

Cathode filaments and focusing cup

Two coils of tungsten wire, each a few millimetres long, lying in slots cut into a block of nickel at the far end of the tube from the target. One coil is short and one is longer.

Rotating anode, target track and rotor

A disc of molybdenum about ninety millimetres across with a band of tungsten and rhenium brazed onto a bevel at its rim, spinning at several thousand revolutions a minute inside the vacuum. The bevel is the most important angle in the device.

Tube housing, insulating oil and lead shielding

A heavy cylinder, lead-lined, filled with oil, with the tube insert suspended inside it and one square window in the wall where the beam is allowed out. It weighs far more than the tube it contains, and almost all of that weight is doing two jobs: holding off a hundred kilovolts and absorbing the photons that were not asked for.

Tube port and inherent filtration

A thin window in the envelope where the beam leaves, the oil in front of it, and the window in the housing wall beyond that. Together they are the filtration nobody chose.

Added aluminium filtration

Two thin sheets of aluminium in a drawer under the port, held by a clip, with a handle to pull them out. They are the cheapest and least interesting-looking part of the machine, and removing them raises the exposure a patient absorbs without improving the radiograph at all.

Collimator, light field and lead shutters

A box bolted under the port with two pairs of lead shutters inside it, a lamp, a mirror at forty-five degrees and a pair of cross-hair wires. The lamp and the mirror exist so that somebody can see where an invisible beam is going.

High-frequency generator and high-tension transformer

A cabinet the size of a wardrobe holding an inverter, a transformer in oil with two bushings on top, a rectifier stack and a control board. It decides how fast the electrons are going when they hit the target, and that single decision is what makes bone look different from soft tissue.

High-tension cables and receptacles

Two cables as thick as a wrist, running from the generator to the two ends of the tube housing, each ending in a plug that screws into a well full of insulating grease. They are the least glamorous expensive part of the room and the one most often damaged by the room being rearranged.

Explore it in the Device Lab

• The exchange rate between the two knobs: Hold the receptor exposure where it is and raise the kilovoltage by fifteen per cent, taking out the milliampere-seconds that the extra penetration allows. Watch three numbers: what the receptor gets, what the patient absorbs, and the contrast.
• Where the contrast actually comes from: Sweep the kilovoltage and watch one quantity that is not on any real console: the fraction of cortical bone’s attenuation that is NOT Compton scattering.
• Two ways to deal with scatter, and only one is free: Set a thick patient and a wide field, then reduce the field and watch the scatter-to-primary ratio fall. Then restore the field and put a grid in instead, and watch the contrast recover at the price of a large increase in exposure.
• Why the fixed system is the blurrier one: Compare the penumbra on the two configurations. 15 m and the mobile unit at one metre, so the fixed room should be the sharper of the two. It is not.
• Measuring it, or predicting it: Make the patient six centimetres thicker on each configuration in turn and watch what happens.

Common faults and what to check

Most reported device problems (FDA MAUDE)

Raw counts of adverse event reports for this device type (FDA product code KPR, MQB), all years. Not adjusted for the number of units in use, so they show what gets reported, not failure rates. Report text is never copied.

Planned maintenance checks

From the BMEssentia procedure library: every 12 months, about 120 minutes, electrical class I, applied part type B.

Test instruments: Non-invasive kVp and dose meter (multimeter for X-ray); Aluminium filters for HVL; Collimation test tool; Electrical safety analyser.

Standards engineers test against

Recent FDA recalls

From the FDA recall database (openFDA), newest first, imported 2026-10-22. 363 recalls on record for this device type. Recall text is the FDA's public text; each recall links to the official record.

Learn it, see it in 3D, ask about it

• Ask Essentia about the X-ray: answers from named sources, with the device open in its 3D Device Lab beside the answer.
• The X-ray on the BMEssentia Platform: the Device Library course, 13 sections from physics to maintenance.
• BMEssentia Medical City: Device Lab 68, the X-ray fully assembled in 3D, with lab tasks and the simulations.

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