Chemical Engineering May 2012 - 23

LumaSense
Equipment News Roundup
THE SENSITIVE SIDE OF
CHEMICAL PROCESSING
Advanced sensors
reduce costs via
reliability, digital
designs and in-situ
measurements
A
s in almost all other aspects of
producing chemicals, processors
are looking for cost-effective
sensing solutions. And they won't
be disappointed by the newest offering
of sensors for the chemical process industries
(CPI). Gas and pH sensors, as
well as spectrometers, are experiencing
noteworthy advancements that allow
the technologies to reduce costs via reliability,
digital and intelligent design
and in-process measurement.
" The big thing in sensors is reliability
and ease of use, which help chemical
processors save money in the end, "
says Fred Kohlmann, product business
manager with Endress+Hauser
(Greenwood, Ind.; www.us.endress.
com). " As competition increases, chemical
processors are looking to maximize
both products and manpower and get
greater yields. And that goes hand in
hand with measuring a variety of parameters
in a way that is better, faster
and less expensive than it has been
done in the past. "
" Expense " means not only the price
tag for the sensor itself, but also relates
to operator friendliness and reliability.
" Calibrating in the field can be tedious
and time-consuming, " says Stefan Van
der Wal, marketing segment manager
for the chemical industries with Mettler
Toledo (Urdorf, Switzerland; www.
mt.com). " Typically analytical instruments,
regardless of the parameter
they measure, are not at all easy to
operate compared to transmitters that
deal with physical parameters, such as
temperature or pressure. "
The DGA (Dissolved Gas Analysis) Solution
from LumaSense is a costeffective
online monitoring solution
based on proven, state-of-the-art
non-dispersive infrared
(NDIR) technology
Compared with traditional zirconia oxide
and paramagnetic sensors, TDL (tunable diode
laser) sensors are much easier to use. They don't
require a lot of specialist know how or time for
servicing and operation. TDL sensors are very robust,
making them efficient and accurate
Troubleshooting sensor problems is
also often considered a difficult and
time-consuming endeavor. " Usually
the whole measuring loop needs to be
taken into account, " says Van der Wal.
" That means the sensor, the cable and
the transmitter, as each of these can
be experiencing a problem. While the
sensor can be simply broken, coated or
in need of recalibration, the cable and
signal may also experience electromagnetic
interference. On the transmitter
side, wiring problems may be
the cause of measurement failure. "
Digital, intelligent sensors
For this reason, the introduction of
digital and intelligent sensors has
made huge leaps toward eradicating
these problems, while reducing the associated
labor and loss of productivity
costs. Oxidation-reduction potential
(ORP), pH, conductivity, dissolved
oxygen and several other parameters
have benefited from the digitalization
of the electrode output signal and the
intelligence that has been integrated
into the technology.
Mettler Toledo has used this technology
to develop the Intelligent
Mettler
Toledo
Sensor Management (ISM) platform,
which allows the electrode itself to
alert operators when it needs to be
replaced. The onboard intelligence includes
a circuit board in the head of
pH electrodes, or other sensors, which
harbors a sophisticated algorithm that
collects various process and sensor
status data. Through continuous dynamic
calculations, the ISM electrode
is capable of predicting when its reliable
operating life will end under the
past and current process conditions.
Similarly, it will alert users when
recalibration is required, which encourages
predictive maintenance
based on when the sensor feels it is
necessary. And because the ISM " sensors "
are self-configuring, the maintenance
engineer needs to spend very
little time at the measurement point.
Upon connecting, the sensor starts
to measure immediately. Any sensor
in need of recalibration can be taken
from the process to the workshop,
where it can be recalibrated using a
laptop instead of a transmitter.
Endress+Hauser has a similar
technology in its Memosens line. This
sensor technology offers inductive
CHEMICAL ENGINEERING WWW.CHE.COM MAY 2012 23
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Chemical Engineering May 2012

Table of Contents for the Digital Edition of Chemical Engineering May 2012
