FEATURE TEST & MEASUREMENT
WE ALL WANT TO TEST QUICKER, SAYS METREL
A
fantasy world? Not since Metrel introduced the auto sequence facility
to its multi-function testers. This testing procedure allows a selected range of tests to be completed with a single press of the test button. Each test is automatically compared to pre-set limits and passed or failed, and the results displayed and stored. It saves so much time, and produces
stable, repeatable results quickly. The auto sequence facility is pre- programmed in to Metrel multi-function testers, ensuring a cost efficient and easy way of installation testing and improving operator safety. This system is ideal for situations where the same test is repeated continuously such as electrical installation condition reports (EICR). The
results can be stored on-board the tester and then downloaded to an IET certificate. The pre-programmed sequence of tests is selected by the
operator depending on the part of the installation to be tested, the earthing system, whether the installation is single- or three-phase and whether there is a RCD present in the installation. Having connected the test leads, and pressed the test button, the tester will automatically perform the tests and indicate if each test is passed or failed. It also tells the operator where their interaction is required.
The key benefit to users of the auto sequence procedures is that they complete the testing up to five times faster than ordinary methods.
Metrel
metrel.co.uk
Vapour permeability and optical fibre strength, spectral shift and sensors
W
ater 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 highly repeatable. The system can control a wide range
of physical conditions from temperature (-80 to over +1000°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.
Versaperm
versaperm.com
16 MARCH 2019 | ELECTRICAL ENGINEERING
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