Fibre relocation errors

Sometimes it is neccessary to disconnect fibre and diffuser. Reconnection can cause a change in the diffuser-fibre distance, which could lead to errors in previous calibrations. Thermal expansion can also be a reason for a changing diffuser-fibre distance .

The following graph shows the change in photomultiplier signal due to a changing fibre distance.

When the fibre is relocated with care relocation errors are around 0.1mm. The thermal expansion coeficient of teflon is 0.00012 mm per degree Celcius.

The graph shows that thermal expansion and fibre relocations do not affect calibrations, if relocatio n is done with care.

Info, questions and remarks, contact: Richard McKenzie. 


Emeritus Researcher – Atmospheric Radiation