Check water vapour permeability of seals

Seals, mastics, adhesives, gaskets, O-rings and enclosures can be highly sensitive to changes in pressure, temperature and water vapour: so how can you measure water vapour permeability?

Seals, mastics, adhesives, gaskets, O-rings and enclosures can be highly sensitive to changes in pressure, temperature and other conditions.

Water vapour, in particular, is extraordinarily invasive and the problems it causes have been estimated to cost UK Engineering over a hundred million pounds each year in ruined products and equipment.

So how can you make the perfect seal? The problem is that many seals which keep out water as a liquid allow it to pass through virtually unhindered as vapour ­ possibly rendering seal useless! Versaperm Limited, a world leader in water vapour permeability measurement, has introduced a quick and simple way to test this and thus help to overcome the difficulty.

The Versaperm WVTR (Water Vapour Transmission) meter was purpose designed for this task.

It can cope with several samples, seals or enclosures at a time, often give a reading in as little as 30 minutes ­ whereas conventional gravimetric measurement takes several days and is significantly less accurate.

The WVTR meter is easy to use and gives a series of digital readouts that can be recorded or simply read off a screen.

It needs no re-calibration and requires, at most, minimal training to give results that can be as accurate as better than one part per million (with some samples a few parts per hundred million).

Sensitivities are in the range 0.05 ­ 3200g/m2/day.

A wide range of variations is available, depending on the specific application, but both single and multi-sample systems and a variety of chambers are available for testing samples from the size of a thimble up to a pallet load and beyond.

As well as manufacturing the instruments, Versaperm also offers a water vapour permeability laboratory service for companies that need to test samples on an irregular basis.

Back to top