Water vapour permeability is critical in optical fibres not only because the strength of polymer coated fibres depends on water vapour activity at the polymer/glass interface (because of stress corrosion) but also due to the spectral shift response of optical whispering-gallery modes due to the adsorption and desorption of water molecules.
It is also vital if you are using the fibre as a sensor (for example in an oil well for gas analysis or to measure temperature or pressure).
Because of this Versaperm has launched a dedicated mass spectrometer version of its successful optical fibre vapour permeability measurement system which works across not just water vapour, but also with every gas or group of gasses.
This is particularly important when using optical fibres for transferring data long distances (especially under water where signal attenuation is particularly important).
The vapour permeability of optic fibres is difficult to determine using conventional techniques and some people simply rely on published values for flat samples, ignoring manufacturing processes which can change permeability by a factor of at least four. Fortunately, Versaperm can measure the value it with an accuracy of well into the Parts Per Million (PPM) or sometimes Parts Per Billion (PPB) ranges. Results are precise and repeatable.
The system can control a wide range of physical conditions from temperature (-80 to over +1,000°C), pressure, environment and partial pressure / humidity.
As well as designing, manufacturing and supplying the equipment to laboratories, including standards laboratories around the world, Versaperm additionally offers both laboratory testing and consultancy services.