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.

V

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.

www.michell.com

Sample Conditioning Systems

A well designed sampling system is key to achieving correct measurement and reliable
long-term operation of any natural gas moisture analyzer. The sample conditioning
system of the OptiPEAK TDL600 applies state-of-the-art filtration and multi-stage
pressure reduction to present a clean, wholly gaseous phase representative sample
for continuous analysis. Systems that disregard the requirements for adequate sample
conditioning will fail to achieve the levels of accuracy promised in the analyzer data
sheet and also may be very costly for the user in the longer term.

Process Analyzers

Whilst the fast response speed of TDL based analyzers is an important advantage,
it is also widely accepted that the quality of the sample conditioning system design
and its finish determine the performance of the entire measuring system. This is
particularly valid for measurement of trace water vapor in single or double digit ppm
ranges where the adsorption and desorption of the water molecules from surfaces in
the conditioning system has to be considered.

Michell Instruments have 40 years of experience with low moisture measurements
in process applications. The OptiPEAK series instruments are supplied with a high
quality sample conditioning system that is optimized for applications in natural gas,
as well as the high speed of response of the analyzer.

Our products are also backed up by global
service and support. With locations on
6 continents and 56 countries, Michell
Instruments offers an extensive network of
factory trained application engineers ready
to analyze your application and deliver the
solution. This allows us to assure customer
satisfaction throughout your products lifetime.

If you can’t find a product to fit your application
contact your local Michell Instruments office,
or visit our website www.michell.com — we’re
here to help.

The Moisture Specialists:

We have the solution for your moisture sensing
needs

With 5 proprietary moisture sensing technologies, Michell Instruments will
tailor solutions to best fit the specifics of your application, as well as the
project budget.

Relative Humidity Sensors:

Designed for a broad range of heavy industrial and process industries.

Ceramic Sensor Technology:

3rd generation of metal oxide for natural gas applications at high pressure
(CNG) and economical, easy gas processing applications.

www.michell.com

Chilled Mirror:

For precise reference measurements at the highest accuracy and NPL or
NIST traceability.

Quartz Crystal Microbalance:

For fast, precise measurement at low ranges in changing backgrounds.

TDLAS:

For fast, precise and low maintenance measurement in natural gas from
1000 ppmV down to 1 ppmV.

Process Analyzers

OptiPEAK TDL600

Process Moisture Analyzer

550mm

(21.65”)

970mm

(38.18”)

600mm
(23.62”)

1000mm

(39.36”)

Technical Specifications

Measurement technology TDLAS

Measurement range 1 ppmV to 1000 ppm

Accuracy ±1% of reading >100 ppmV

Repeatability <1 ppmV (long term stability <0.1 ppmv/

Limit of detection 1 ppm

Available units ppmV, lb/MMSCF, mg/Nm3, dew point °C

Response speed Optical response 0.2s

Environmental Conditions

Indoor version:

Outdoor version*:

Outdoor with cooling option*:

± 1ppmV <100 ppm

year)

V

or °F (ISO18453 or IGT#8)

Display update 2 to 3s

+10 ºC to +45 ºC

-20 ºC to +45 ºC

-20 ºC to +55 ºC

V

V

Electrical Specifications

Supply voltage 110 V AC or 230 V AC 50/60 Hz

Power requirements

Analog signals

Digital communications RS485 ModBus RTU

Data logging Logs all process variables with a user

Indoor system:

Outdoor system:

Input:

Output:

80 W
180 W

2 x 4–20 mA user configurable
3 x 4–20 mA, 3 alarms 250 V AC, 3A
(volt-free contacts)

selectable sample period in the range of
10s to 1 day

Local interface 4.3” color LCD with touch pad operation

Electrical connections 3 x M20 entries for cable glands

Calibration

Factory method 3-point, traceable to NPL and NIST

Recommended calibration None required, dependant on user or

quality system requirements

Physical Specifications

Sample flow rate 1 Nl/min cell sample

Inlet pressure Maximum 1450 psig (100 barg)

Outlet pressure Cell vent 0.7 to 1.4 bara

Enclosure type/ packaging Aluminium alloy, explosion proof,

Gas connections 1/4” NPT (F)

Weight 40kg (88lbs) (without sampling system)

Sample system enclosure 304L or 316L stainless steel

Hazardous area certification

IECEx:

cQPSus:

TC TR Ex:

*If installed outside, the analyzer must be shaded from direct
sunlight to prevent heating effects through sun radiation

1 to 5 Nl/min sample filter by-pass

Filter by-pass maximum 3 barg

polyester coated, IP66, NEMA 4

ATEX:

II 2 G Ex d ib op is IIC T5 Gb
Ex d ib op is IIC T5 Gb
Tamb –20 °C to +60 °C
Class I, Division 1, Groups A, B, C, D, T5,
Tamb –20 °C to +60 °C, IP66
1 Ex d ib op is IIC T5 Gb

Sampling Conditioning Systems

Indoor Version

OptiPEAK TDL600 with sampling system on
panel mounting

Outdoor Version

OptiPEAK TDL600 and sampling system with
enclosure, including heater

Michell Instruments Ltd 48 Lancaster Way Business Park, Ely, Cambridgeshire, CB6 3NW

Tel: [phone], Fax: [phone], Email: [e-mail], Web: www.michell.com/uk

Michell Instruments adopts a continuous development programme which sometimes necessitates specification changes without notice.
Issue no: OptiPEAK TDL600_ 97470_V5_UK_Datasheet_0419

© 2018 Michell Instruments