Michell Instruments TDL600 Specifications

Process Analyzers

OptiPEAK TDL600

Moisture in Natural Gas Analyzer

The next generation TDLAS Analyzer for automatic online measurement of moisture in variable
compositions of natural gas and biomethane. The OptiPEAK TDL600 Tuneable Diode Laser
Analyzer employs the latest techniques in laser absorption spectroscopy and signal processing
power to offer a robust high performance analyzer, designed specifically for the measurement
of moisture in natural gas. This non-contact technology requires minimal maintenance, even in
demanding applications such as changing methane concentrations or sour gas. The analyzer is
fully hazardous area certified and delivers class-leading measurement performance, stability and
detection sensitivity.

Highlights

• D-MET system: Factory ready for varying gas
compositions e.g. after stream blending, in shale gas
or biomethane

• Operating range down to 1 ppmV

• Sour gas compatible

• Simple installation and setup

• Low maintenance

• IECEx, ATEX and cQPSus certified for EExd flameproof

• Integrated sample handling

• Proven Michell Instruments quality: 40 years of
expertise in moisture measurement built into the
design

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Applications

• Natural gas glycol dehydration

• Natural gas transmission monitoring

• Custody transfer

• Natural gas storage

• Offshore export pipeline natural gas

• LNG receiving / re-gasification plants

• Vaporized NGL

• Biomethane

Process Analyzers

40 Years of Experience with Moisture and Hydrocarbon
Dew-Point Measurement in Natural Gas

The control of moisture and hydrocarbon dew point is critical
for the operational safety and efficiency of the plant
equipment in upstream through to downstream processes.

We at Michell Instruments have been developing expert
moisture sensing instruments and systems for 40 years.
Over this time, we have gained extensive knowledge of
applications in natural gas with over 1000 analyzer
installations in sites across the globe. Today Michell
Instruments offers customers in the oil and gas industry a
suite of complementary moisture and hydrocarbon dew­point analyzers and systems.

The OptiPEAK Difference

Performance

• High accuracy with lower detection limit of <1 ppm

• Range of 1 to 1000 ppm

The OptiPEAK TDL600’s lower detection limit (LDL) of less
than 1 ppmV makes the instrument a class leader in single
path TDLAS moisture analyzers currently commercially
available.

The maintenance-free, simple dual pass cell offers reliable
measurement results throughout its range. It combines
sensitivity and robustness without the high top-end range
limit which could make the analyzer likely to saturate quickly
at higher moisture levels. This is sometimes the case with
comparable, costly and difficult to maintain multi-pass
(Herriot) cells. With its accuracy of 1 ppmV the analyzer is
future proof and comfortably exceeds the requirements of
the main international natural gas quality harmonization
guidelines in Europe and United States.

V

Dynamic background gas
compensation

• D-MET — active gas composition compensation for
multi-source dynamic gas streams: shale gas and
biomethane ready

Natural gas stream compositions can vary. In some
applications it is difficult to use an older generation TDL
instrument which can only be tuned to one defined gas
composition. Michell Instruments’ next generation TDL
hygrometers overcome this limit. The OptiPEAK TDL600
utilizes the innovative D-MET System, dynamic background
gas compensation. For the user, this means that the moisture
measurement is virtually independent of changes in the
methane level. No further manual correction factors are
required.

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Reliability

• Signal drift reduction — built-in, continuous laser
optimization

Tuneable diode lasers can drift. This inherent property of
diode lasers can lead to reduction in sensitivity and drift in
measured readings. The OptiPEAK’s built-in continuous laser
optimization system ensures that the laser remains locked to
the correct water absorption peak for the highest
measurement integrity at all times.

• High-accuracy temperature control

For the optimal performance of any TDL hygrometer the
temperature stability is of highest concern. The OptiPEAK
series not only utilizes the highest quality laser with
exceptional life span, but also has a sophisticated multi­stage control system to maintain the temperature of the
laser to within tight limits.

Simplicity

• Human Machine Interface (HMI)

The TDL600 provides a highly intuitive, color, menu-driven
interface, utilizing a capacitive touch pad. This allows
operation and interrogation of the analyzer in the field with
no need for a hot-works permit. Navigation is easy and there
is no need for a stylus.

• Easy integration into existing control systems

The OptiPEAK TDL600 is equipped with 3 programmable
4–20 mA analog outputs and a digital output utilizing the
widespread ModBus Protocol for easy connection to a SCADA
or other user-defined data acquisition system.

• Integrated sampling system

The OptiPEAK series is supplied with a high quality, in-house
designed, sample conditioning system that is optimized for
the applications in natural gas as well as the high speed of
response of the analyzer.

• Remote application software supplied as standard

Allows remote control and configuration of the analyzer to
simplify operations on large, distributed locations.

Reduced cost of ownership

• Minimum installation and maintenance

With its integrated sampling system and small footprint, the
OptiPEAK TDL600 can be easily retrofitted into existing plant
infrastructure. Due to the inherent stability of the instrument,
regular field calibration is not required under normal
operating conditions. The analyzer will perform reliably for
many years with just basic maintenance and housekeeping.

• Built-in self verification

The OptiPEAK TDL600’s innovative self-verification and self­compensation system checks itself against calibration data
on every update cycle, adjusting if necessary, without the
need for an additional gas reference cell. This function is
extremely useful after a system upset — there is no need for
a lengthy setup procedure.

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