Michell Instruments Liquidew I.S Specifications

Process Analyzers

Liquidew I.S.

Moisture in Liquid Analyzer

On-line measurement of moisture content in liquids is accurate, fast and reliable with the
Liquidew I.S. Moisture in Liquid Analyzer from Michell. A wide variety of non-polar liquids can
be measured continuously, on-line, including fl ammable liquids and hazardous area applications,
petrochemicals, power industry and pharmaceutical manufacturing.

Highlights

• Simple, cost-effi cient operation and low maintenance

• Retrofi t functionality, easy to integrate into existing
sampling or distribution systems

• High integrity moisture in liquid measurement from

0.01 ppm

• Multi-channel with up to four completely independent
measurement channels

• Robust design for undisturbed operation in many
non-polar liquids over a long time

• Two 4-20 mA confi gurable outputs and digital
Modbus RTU-based communication

• Replaceable sensor element with Michell Calibration
Exchange Service for reliable cost-effi cient calibration

• NIST and NPL traceable calibration

• EExd version available

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to saturation point

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Applications

• Naphtha feedstock to isomerization catalyst

• Hexane solvent in HDPE and LDPE process

• Benzene in styrene manufacture

• LNG LPG production and product checking

• Diesel and aero fuels to avoid liquid water phase
separation

• BTX process monitoring — benzene, toluene and
xylene

• Ethylene and proylene feed to polymer process

• Butadiene for the manufacture of synthetic rubber.

Process Analyzers

Michell Liquidew I.S.
Moisture in Liquid Analyzer

Michell Liquidew I.S. moisture in liquid analyzer provides a
complete solution for accurate, on-line moisture measurement
in process liquids, and offers many advantages over sample
collection and laboratory analysis methods.

Continuous on-line measurement allows monitoring and
control of moisture conditions to achieve optimum effi ciency
for production or maintenance. Intrinsically safe sensors, with
a sampling system, can be installed in the hazardous zones to
minimize sample transportation time and ensure a fast response
to process moisture changes. The rack-mounted Liquidew I.S.
Control Unit, which is conveniently located in a safe area,
provides real-time display of moisture content, user settable
alarms as well as analog output and digital communications.

The Control Unit is connected to the sensors/sampling system
in the fi eld by standard instrument pairs cable, so existing cable
runs can often be used where Liquidew I.S. is installed as a site
retrofi t.

The Control Unit in multi-channel MCU format can also
include moisture in gas analysis function by combining with
Promet I.S. Moisture in Gas Analyzer.

Accurate on-line moisture measurement in liquid

Michell’s Calibration Laboratories are world recognized through
the UKAS accreditation scheme under the auspices of EAL
(European co-operation for the Accreditation of Laboratories).
Each sensor is calibrated and certifi ed traceable to the humidity
standards of leading international metrology institutes, NPL
(UK) and NIST (USA), so assuring correct measurement of the
moisture in your process.

Certifi ed Intrinsically Safe

Liquidew I.S. sensors and sampling systems are designed for
fl ammable and non-fl ammable liquid within hazardous areas.
ATEX certifi ed by EECS for use in hazardous areas to II 1G EEx
ia IIC T4. Complete packages conforming to NEC Class 1 Div 1
or IECEx certifi cations are also available. Liquidew I.S. carries
GOST pattern approval and GOST Ex.

Flexible confi guration. Total analyzer system tailored
to specifi c customer requirements

Liquidew I.S. is available in a multi-channel format (MCU).
This MCU enables up to four measurement channels within
a single 19” sub-rack unit. The sister product for moisture
in gas analysis, Promet I.S., can be combined together with
Liquidew I.S. into an MCU to enable both gas and liquid
samples measurement with a single analyzer system. With the
MCU, each measurement channel functions independently, so
that any maintenance on one channel will not affect the others.
Customers can also order blank channels for future expansion.

The Liquidew I.S uses the rugged Easidew PRO I.S. sensor,
allowing the transmitter to be installed directly outdoors.

Channel connectors on back of MCU

Features

Reliable

Michell’s Thick- and Thin-fi lm Ceramic Moisture Sensor is
exceedingly durable; chemically inert materials coupled with
physical resilience provide long-term reliable service in liquid
phase measurements.

The robust construction prevents Michell sensors from damage
caused by dense liquid fl ow or even pressure shocks from rapid
process pressure changes during start-up and maintenance.

Easy to use with complete functionality

The 19” sub-rack mounting Liquidew I.S. Control Unit provides
complete operational functionality. The bright alphanumeric
LED display with auto-scale function gives measurement
values across six orders of magnitude, from sub-ppm levels
to saturation conditions. There are pre-set saturation constant

) values of most common hydrocarbon liquids for moisture

(C

S

calculation, together with 2 user defi ned liquids and ability to
mix any 2 liquids from the list, so the user has the fl exibility
to select or enter the appropriate liquid profi le for the specifi c
application.

Four user-adjustable alarm points and two analog 4-20
mA outputs are provided as well as a digital RS485 RTU for
connection to external devices.

Simple to maintain with a sensor calibration exchange
program

For Liquidew I.S., calibration maintenance is simple. The unique
Michell Calibration Exchange Service offers fast, world-wide
delivery of replacement ceramic sensors certifi ed traceable to
metrology standards of NPL and NIST. As the calibration data
for the sensor is factory programmed into on-board non-volatile
memory, fi tment of a Calibration Exchange Sensor renews the
calibration, with minimal down-time. No programming or data
input is required by the user to complete the calibration process.
The Calibration Exchange Service facilitates a professional,
scheduled user QA programme at a lower cost than a traditional
‘return to manufacturer’ re-calibration service.

Retrofi t ready

If customers or system integrators wish to use their own
sampling systems, the analyzer solution can easily be integrated
into any existing sampling or distribution system offering an
extremely cost-effi cient, low-maintenance, multi-channel
solution that can be cascaded to any number of channels.

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Best practice sampling systems

The design of the Liquidew I.S. Premium Sampling System
has drawn on Michell’s 35 years of expertise in on-line process
gas analyzers. Particulate fi ltration is provided in single or dual
stages so that sensor and system performance is maintained
even in processes prone to contamination. A panel-mounted
version of the sampling system and sensor are offered for
internal installations, while various enclosures and heating
options are available for fi eld installation next to the sample
source. Sample cooling, using a water heat exchanger, is
available for process fl uids at elevated temperature.

Process Analyzers

With Liquidew IS the amount of dissolved moisture dispersed
throughout the immiscible process liquid is measured on-line in
real time in units of ppmW moisture content using Henry’s Law:

C (ppm

Where

C = Moisture concentration
C
measurement temperature
e = Actual water vapor pressure derived from the
measurement dew-point temperature
es = Saturation water vapor at the measured temperature

The advanced fi rmware of Liquidew I.S. provides moisture
measurements in ppm
Law using pre-programmed saturation concentration (CS)
values for the most common hydrocarbon liquid applications.
A proportional mixing setting can be used for mixtures of two
solutes, such as the propane and butane in LPG. Two user
programmable entry tables enable CS values to be entered for
other solutes or for complex fl uid compositions where the user
may wish to enter their own CS values either from their own
sources, or from laboratory analysis of their process samples
or estimated values from proportional calculation based on the
CS values for each of the major components in the solute mix.

) = CS x e/e

W

= Saturation concentration specifi c to the fl uid at the

S

s

through the application of Henry’s

W

Liquidew I.S Sampling system

If your need is not accommodated by standard options, Michell’s
Systems Engineering department will work with you to provide
a customized solution for your specifi c application.

Technology

Reliable and robust sensor design is fundamental to achieving
accurate measurement of moisture in liquids over a long period
of time. Proprietary thick- and thin-fi lm techniques are applied
in the Michell Ceramic Moisture Sensor. Base metal layers
on semi-conductor grade ceramic substrate sense dissolved
moisture within the sample liquid fl ow. The inert materials of
the sensor have a high resistance to aggressive media while
the inherent strength of the sensor and the thermal bonded
connections to the active device ensure reliable operation even
in dense fl uid samples.

The Ceramic Sensor responds to the partial pressure of water
vapor of dissolved moisture in the liquid being measured,
which is directly related to the dew-point temperature. Every
Liquidew I.S sensor is calibrated against fundamental dew point
measurement systems in Michell’s world-class laboratory, which
is internationally accredited and directly traceable to both NPL
(UK) and NIST (USA) base standards.

Moisture
Molecules

Permeable Gold film

g

g

Hygroscopic Mono-layer

Base Electrode

g

Ceramic Substrate

g

Moisture
Molecules

Structure of the Michell Ceramic Moisture Sensor

g

g

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Operation of the Michell Ceramic Moisture Sensor

Process Analyzers

Technical Specifi cations

Sensors

Sensor technology Michell Ceramic Moisture Sensor

Sensor version Easidew PRO I.S.

Measurement range 0.001 to 1000 ppm

Calibration range -100 to +20°Cdp

Accuracy Dew

point:

Moisture
content:

Resolution 0.1°C between +20 and -100°Cdp

Temperature
measurement

Temperature
measurement range

Temperature
measurement
accuracy

Analysis pressure Up to 5 MPa (50 barg)

Analysis temperature 0 to +50°C
Sample fl ow rate Min 0.01 l/min, max 10 l/min

Calibration Traceable to British (NPL) and American (NIST)

actual range dependent on solubility of sample
fl uid

±1°C between –59.9 & +20°Cdp
(±1.8°F between -75.9 to +68°Fdp)
±2°C between –60 & -100°Cdp
(±3.6°F between -76 to -148°Fdp)

±10% of reading
±20% of reading

Pt100

-20 to +70°C

Accuracy: ± 0.2°C

0.1 to 0.3 l/min recommended

National Humidity Standards

; Higher range on request,

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Certifi cations

Hazardous area
certifi cation

Pattern Approval GOST-R, GOST-K

ATEX II 1 G Ex ia IIC T4 Ga (–20°C to +70°C)

IECEx Ex ia IIC T4 Ga (–20°C to +70°C)

TC TR 0Ex ia IIC T4 Ga (–20°C to +70°C)

FM Class I, Division 1, Groups A B C D, T4

cCSAus Class I, Division I Groups A B C D, T4

Control Unit

Display Two line 6-digits LED, displaying moisture

Analog output Two 4-20 mA (max. load 500 Ω) - User

Digital output RS485 Modbus RTU

Display mode Moisture content (ppm

Display resolution 0.1°Cdp, 0.1°Fdp, 0.001 ppm

Alarms Four alarm relays. Control action and setpoint

I.S. Barriers Galvanic isolation type, integrated to Control Unit

Power supply 85 to 265 V AC 50/60Hz or 10 to 72 V DC

Enclosure 19” sub rack unit

Operating
environment

content / dew point (user toggle) and
temperature

confi gured for parameter, unit and range

)
Dew point (°C or °F)
Temperature (°C or °F)

are user programmable
Two Form C contacts rated 10 A, 240 V AC or 8
A, 24 V DC. Non-inductive load
Two Form A contacts rated 5 A, 240 V AC or
4A, 24 V DC. Non-inductive load

10 W max power consumption

Dimensions 132 x 483 x 375mm (h x w x d)
(100mm minimum clearance depth for cables
and vents)

Indoor, safe area, 0 to +50°C, < 90% RH

W

, 0.1°C temp

W

Premium Sampling Systems

Enclosure 304 stainless steel (EN1.4301) enclosure.

Enclosure mounting Stainless steel wall mounting brackets

Enclosure ingress
protection

Enclosure temperature
control

Heater power supply 110/120 or 220/240/255 V AC, 50/60 Hz Power

Operating
environment

Sample cooling option Recommended for process fl uid temperatures >

Option for complete enclosure in 316 stainless
steel (EN1.4401); All fi xtures stainless steel;
Galvanised steel internal mounting plate; Open
panel version available for indoor installation
Dimensions 800 x 600 x 300mm (h x w x d)

IP66

Heater/thermostat options for fi xed set-point
+20°C or adjustable set-point range 0 to control
+50°C

consumption 100 W max.

Shaded position, on or off shore, -20 to +40°C
(-40 to +60°C max. transient)
Enclosure cooling option recommended for
climate ambient > +45°C

+40°C
Plant water supply required, ≤ +30°C

Michell Instruments Ltd, Rotronic Instruments Corp. 135 Engineers Road, Suite 150, Hauppauge NY 11788
Tel: [phone], Email: [e-mail], Web: www.michell.com/us

Michell Instruments adopts a continuous development programme which sometimes necessitates specifi cation changes without notice.
Issue no: Liquidew I.S_97153_V5.2_US_1018

© 2018 Michell Instruments