Maintenance
116
Senscient ELDS™
Rev 15
GB
In the event that the signal reaching the Receiver is low after the lens-windows have been
(6)
cleaned, check the alignment of each end of the system using the alignment telescope. (See
section 4.3.2)
Perform a functional test using SimuGas™ Live or SimuGas Auto (see section 5).
(7)
6.2. Cleaning Lens-Windows
The optics of Senscient’s ELDS OPGDs were designed in the expectation that operational service
would result in the exposed surfaces of the TX & RX lens-windows becoming contaminated by the
various airborne contaminants encountered at industrial facilities around the world. In contrast with
NDIR OPGDs, the use of Harmonic Fingerprint technology in ELDS OPGDs means that none of
the airborne contaminants likely to be deposited upon the lens-windows of an ELDS OPGD will
give rise to false alarms or other spurious effects.
The principle effect of the build-up of contaminants upon the exposed lens-windows will be the
gradual reduction of the amount of signal reaching the Receiver’s infrared detector from the
Transmitter. In the event of the build-up of extremely heavy contamination, this could result in an
ELDS OPGD signalling either a Low Signal or a Beam-Block condition, suggesting that the system
be visited and its optics cleaned if necessary.
Cleaning of the lens-windows of the TX or RX of an ELDS OPGD requires the following:
A reasonable quantity of a pure, clear solvent such as tap water or IPA, preferably in a bottle
with a nozzle through which the solvent can be squeezed.
A quantity of clean, disposable cloth or paper towelling, preferably of a type that will remain in
one piece when soaked with cleaning solvent and repeatedly rubbed.
An alignment telescope.
The
OBJECTIVE
of cleaning the lens-windows of an ELDS OPGD is to remove any contaminants
that might have built up on the exposed surfaces
WITHOUT
leaving behind a smeared film.
Achieving smear-free, film-free results is much simpler if relatively pure, clear solvents are used,
such as tap water or IPA (isopropyl alcohol).
Avoid
using cleaning liquids containing detergents or
that are coloured, because the detergent or colour components will tend to leave a film residue
after the liquid has evaporated.
CAUTION
Do not use aggressive solvents or abrasives on the lens-windows of Senscient ELDS™ OPGD
units.
Summary of Contents for Senscient ELDS 1000 series
Page 58: ...Installation Commissioning 58 Senscient ELDS Rev 15 GB 2 x Mounting Brackets ...
Page 140: ...Certification 140 Senscient ELDS Rev 15 GB 9 1 2 Control Drawing CENELEC ATEX ...
Page 142: ...Certification 142 Senscient ELDS Rev 15 GB 9 1 4 Control Drawing CSA US Canada ...
Page 159: ...Appendix D Manufacturer s EC Declarations Senscient ELDS Rev 15 159 GB ...
Page 160: ...Appendix D Manufacturer s EC Declarations 160 Senscient ELDS Rev 15 GB ...
Page 184: ...For local MSA contacts please visit us at MSAsafety com Because every life has a purpose ...
