Hologic makes a great Bone Densitometer(link is external). As a matter of fact, from their QDR-4500 series introduced in 1995, to their Discovery series, still manufactured today, Hologic has arguably had the most reliable DEXA scanner on the market.

And a lot of that reliability has to do with Hologic’s X-ray Tube and High-Voltage Tank assembly. As the beating heart of the Hologic DEXA, the X-Ray tube is enclosed in an oil-filled tank, which both cools the tube and prolongs its life.

Since these two assemblies are inextricably connected, both literally and figuratively, you can’t separate one from the other. This is why you’ll hear some people call this assembly a tank, while others call it a tube. Really, it is both!

A VERY GOOD tank membrane-- just like NEW!

Weighing in at 250lbs, the Hologic tank is not an easy beast to replace. Typically your new or refurbished tube will be shipped in a wooden crate. The swapping out of the tank usually takes two guys and is a significant undertaking that you’ll want to leave to an experienced service engineer who has tackled this task before. The tank is filled with oil and sealed with an expandable black rubber membrane. Typically the membrane fails due to the heat it is subjected to when the X-ray tube is active, as well as constant expansion and contraction due to the heating and cooling of the oil inside. If your rubber membrane is failing you will often see fine cracks and a slick surface— sure signs that the membrane is aging and probably starting to leak oil. This eventual failure means that an older tube will begin to seep, letting air inside, and causing the tube to “slosh” as the oil level diminishes, leading to the life of the tube/tank assembly being shortened. You won’t be able to see the rubber membrane without removing several covers, and the X-Ray Controller Assembly, so you might not want to try unless you are very comfortable with a screwdriver and removing electronics parts.

The black rubber membrane on new or refurbished tanks have a dry, pliant, nicely concave surface when cold, showing that a vacuum is still present inside. Older tank membranes can often be seen to have a flat or even convex surface, with a rough or slightly crackled exterior.

Currently Hologic charges $8000-13,000 for a new or remanufactured tank/tube assembly— plus labor to install.

As an alternative, we can provide good, tested, fully warrantied tanks for about 30% less. We also offer installation nationwide, and usually have 1-2 tanks on the shelf ready to ship.

If your local service people tell you you have a bad, failing or leaking tank, give us a call. 800-722-3646, 239.454.9555 or Contact Us!