EBME Forums Forums Maintenance Technical Assistance dental x-ray tube problem

hi dear brothers
i need assistance, a small xray tube for dental radiography that has expose sound ( like ggggggggggggggz) but it does not have any effect or image on film,

Is that the sound you normally hear, Saeed? What is it ... a mechanical timer, or a "buzzing" transformer?

And are you sure that there's no exposure?

You could start by checking the tube filament for continuity.

Good Luck.

Geoff sir,
Based on my understanding, i think the tube is arcing already...

dear Hannis
the sound in not from timer, the filament has 6 ohm,
the mail supply 220 is inserted in tube( there is no transformer)

That doesn't sound right, Saeed. You need at least 40 kV or so to generate x-rays.

If that noise is abnormal, maybe something is breaking down (flashing over, arcing across, whatever) as Bala suggests.

Hi, In most dental x-ray machines the tube and the transformer are contained within the head. The head will have two connections from the mains supply via some form of timer.Usually the timer switches the mains on to both the filament and HT transformer at the same time. As a result the filament lights at the same time as the HT is applied. Is the noise coming from the head? If you tilt the head from side to side can you hear oil splashing? If the answer to either of these questions is yes then the tube may be arcing over or broken.