Michell Instruments Condumax II Operating Manual
Condumax II
Hydrocarbon Dew-Point Analyzer
User’s Manual
97081 Issue 29.1
July 2019
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Condumax II
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Condumax II User’s Manual
Contents
Safety ...............................................................................................................................vii
Electrical Safety .................................................................................................................vii
Pressure Safety .................................................................................................................vii
Toxic Materials ...................................................................................................................vii
Repair and Maintenance .....................................................................................................vii
Calibration (factory validation) ...........................................................................................vii
Safety Conformity ..............................................................................................................vii
Abbreviations .................................................................................................................... viii
Warnings .......................................................................................................................... viii
1 INTRODUCTION ................................................................................................1
1.1 General ..................................................................................................................1
1.2 System Description ..................................................................................................1
1.2.1 Sample Gas Path ........................................................................................... 1
1.2.2 Operating Overview....................................................................................... 3
1.2.3 Condumax II User Display and Interface ......................................................... 3
1.2.4 Calibration .................................................................................................... 3
1.3 Condumax II Analyzer Storage Instructions ...............................................................4
2 INSTALLATION ..................................................................................................5
2.1 Electrical Safety ...................................................................................................... 5
2.1.1 Equipment Ratings and Installation Details ...................................................... 5
2.2 Hazardous Area Safety ............................................................................................8
2.3 Pressure Safety ....................................................................................................... 9
2.4 Lifting and Handling ................................................................................................ 9
2.5 Measurement System ............................................................................................ 10
2.5.1 Gas Connections, Sample Extraction & Conditioning ...................................... 11
2.5.2 Power Connection ...................................................................................... 15
2.5.3 Analog and Digital Communications ............................................................. 16
2.6 Condumax II Start-Up Purge Procedure .................................................................. 17
2.7 Sample Gas Flows ................................................................................................. 18
2.8 Sample Flow Alarms .............................................................................................. 19
3 OPERATION ....................................................................................................20
3.1 Timing Synchronization.......................................................................................... 20
3.2 Recovery Phase ....................................................................................................20
3.3 Measurement Phase .............................................................................................. 20
3.3.1 Water Dew-Point Measurement .................................................................... 21
3.3.2 Signal Changes and Trip Point ...................................................................... 21
3.3.3 Sensitivity Calibration .................................................................................. 22
3.3.4 Adjustment of Measurement Sensitivity to User Defined Reference ................. 23
3.4 User Interface ....................................................................................................... 24
3.4.1 Interface Controls ...................................................................................... 24
3.4.2 ‘Up/Down Arrow’ Buttons ............................................................................. 24
3.4.3 ‘SELECT’ Button ......................................................................................... 25
3.4.4 ‘MENU/MAIN’ Button ................................................................................... 25
3.5 Menu Structure ..................................................................................................... 26
3.6 Main Page ............................................................................................................ 27
3.7 Menu Page ........................................................................................................... 27
3.8 Status Pages ......................................................................................................... 28
3.8.1 Status Page 1 ............................................................................................. 28
3.8.2 Status Page 2 ............................................................................................. 29
3.9 Logging Menu Page ............................................................................................... 30
3.9.1 Logged Data Page ....................................................................................... 30
3.9.2 Statistics .................................................................................................... 31
3.9.3 Viewing Historical System Faults ................................................................... 31
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Condumax II User’s Manual
3.10 Adjusting and Viewing System Variables .................................................................32
3.10.1 Enter Password ........................................................................................... 32
3.10.2 Variable Pages ............................................................................................ 32
3.10.3 Variables Page 1 ......................................................................................... 33
3.10.4 Variables Page 2 ......................................................................................... 33
3.10.5 Variables Page 3 ......................................................................................... 33
3.10.6 Variables Page 4 ......................................................................................... 34
3.10.7 Variables Page 5 ......................................................................................... 34
3.11 Sensitivity Calibration ............................................................................................ 35
3.11.1 Executing the Sensitivity Calibration ............................................................. 35
3.11.2 Viewing the Calibration Data ........................................................................ 35
3.12 Water Dew-Point Sensor Information ...................................................................... 36
3.13 Contact/About Information .................................................................................... 36
4 MAINTENANCE ................................................................................................37
4.1 Calibration ............................................................................................................ 37
4.2 Enclosure Cover and User Interface ........................................................................ 38
4.3 Inspection/Cleaning of Hydrocarbon Sensor Cell Optical Surface ............................... 39
4.4 Replacement of the Hydrocarbon Sensor Cell Assembly ........................................... 40
4.5 Replacement of the Water Dew-Point Sensor ........................................................... 41
4.6 Troubleshooting .................................................................................................... 42
4.6.1 Error Messages ........................................................................................... 42
4.6.2 Logged Error Codes ..................................................................................... 43
4.6.3 mA1 Output Analyzer Fault Alarm ................................................................. 44
4.6.4 Heat-Pump Depression ................................................................................ 45
Figures
Figure 1 Power Connection Connector ........................................................................... 5
Figure 2 Earthing Stud And Nut Washer Assembly .......................................................... 6
Figure 3 Condumax Dimensions .................................................................................. 10
Figure 4 Flow Schematic ............................................................................................. 11
Figure 5 Typical Phase Envelope for Northern Europe Natural Gas .................................. 14
Figure 6 Wiring Hook-Up Diagram ............................................................................... 15
Figure 7 Minimum Requirements for Start-Up Purging ................................................... 18
Figure 8 Sensitivity Calibration Plot (Example) .............................................................. 23
Figure 9 User Interface ............................................................................................... 24
Figure 10 ‘UP/DOWN ARROW’ Buttons........................................................................... 24
Figure 11 ‘SELECT’ Button ............................................................................................ 25
Figure 12 ‘MENU/MAIN’ Button ..................................................................................... 25
Figure 13 Menu Structure ............................................................................................. 26
Figure 14 MAIN Page With Wdp Sensor Fitted ................................................................ 27
Figure 15 MAIN Page Without Wdp Sensor Fitted ........................................................... 27
Figure 16 MENU Page ................................................................................................... 27
Figure 17 STATUS Page 1 ............................................................................................. 28
Figure 18 STATUS Page 2 ............................................................................................. 29
Figure 19 LOGGED DATA Page ...................................................................................... 30
Figure 20 STATISTICS Page .......................................................................................... 31
Figure 21 Logged Error Codes ....................................................................................... 31
Figure 22 Password Page .............................................................................................. 32
Figure 23 Variables Page .............................................................................................. 32
Figure 24 Sensitivity Calibration Page ............................................................................ 35
Figure 25 Sensitivity Calibration Data Page .................................................................... 35
Figure 26 Water Dew-Point Sensor Information Page ...................................................... 36
Figure 27 Contact/About Information Page .................................................................... 36
Figure 28 Error Messages ............................................................................................. 42
Figure 29 Logged Error Codes ....................................................................................... 43
Figure 30 Reading Holding Registers State Diagram ........................................................ 68
Figure 31 Write Single Register State Diagram ............................................................... 70
Michell Instruments v
Condumax II User’s Manual
Appendices
Appendix A Technical Specications ..............................................................................47
A.1 Mounting Drawing ....................................................................... 48
A.2 Flow Diagram ............................................................................. 49
A.3 Wiring Hook-Up Diagram ............................................................. 50
Appendix B Modbus RTU Communications ....................................................................52
B.1 Introduction ...............................................................................52
B.2 Modbus RTU Basics ..................................................................... 52
B.3 Modbus RTU Basics ..................................................................... 52
B.4 Register Map .............................................................................. 53
Appendix C Software ................................................................................................... 57
C.1 System Requirements .................................................................. 57
Appendix D Variables Pages ......................................................................................... 59
D.1 Variables Page 1 .........................................................................59
D.2 Variables Page 2 .........................................................................61
D.3 Variables Page 3 .........................................................................62
D.4 Variables Page 4 .........................................................................63
D.5 Variables Page 5 .........................................................................65
Appendix E Modbus RTU Details ..................................................................................67
E.1 Message Framing ........................................................................ 67
E.2 Implemented Functions ...............................................................68
E.3 Exceptions .................................................................................. 72
Appendix F Number Formats ....................................................................................... 74
Appendix G Hazardous Area Certication ......................................................................80
G.1 Product Standards ....................................................................... 80
G.2 Product Certication ....................................................................80
G.3 Global Certicates/Approvals ........................................................ 80
G.4 Special Conditions of Use ............................................................. 81
G.5 Maintenance and Installation ....................................................... 81
Appendix H Quality, Recycling, Compliance & Warranty Information ................................ 83
Appendix I Analyzer Return Document & Decontamination Declaration .......................... 85
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!
Safety
This manual contains all the required information to install, operate and maintain the Condumax II.
Prior to installation and use of this instrument, this entire manual should be read and understood.
Installation and operation of this product should be carried out by suitably competent personnel only.
The operation of this product must be in accordance with the terms of this manual and associated
safety certificates. Incorrect installation and use of this product for other than its intended purpose
will render all warranties void.
This product is intended for use in a Hazardous Area and is awarded an ATEX, IECEx and CSA
Certificate. The relevant certificates should be fully examined prior to installation or use of this
product.
Where this hazard warning symbol appears in the following
sections, it is used to indicate areas where potentially hazardous
operations need to be carried out and where particular attention to
personal and personnel safety must be observed.
Electrical Safety
The instrument is designed to be completely safe when used with options and accessories supplied
by the manufacturer for use with the instrument. The input power supply voltage limits are 90 to
260 V AC, 47/63 Hz.
Pressure Safety
DO NOT permit pressures greater than the safe working pressure to be applied directly to the
instrument. Refer to the Technical Specifications in Appendix A.
Toxic Materials
The use of hazardous materials in the construction of this instrument has been minimized. During
normal operation it is not possible for the user to come into contact with any hazardous substance
which might be employed in the construction of the instrument. Care should, however, be exercised
during maintenance and the disposal of certain parts.
Repair and Maintenance
The instrument must only be maintained either by the manufacturer or an accredited service agent.
Refer to www.michell.com for details of Michell Instruments’ worldwide offices contact information.
Calibration (factory validation)
Prior to shipment, both the hydrocarbon dew-point cell and the water dew-point cell undergo
stringent factory calibration to internationally traceable standards - NPL (UK) and NIST (USA). Due
to the inherent stability of the instruments, only periodic calibration maintenance is required under
normal operating conditions. Refer to Section 1.2.4 and 4.1 for more information.
Safety Conformity
This product meets the essential protection requirements of the relevant EU directives. Further
details of applied standards may be found in the product specification.
Michell Instruments vii
Abbreviations
The following abbreviations are used in this manual:
AC alternating current
atm pressure unit (atmosphere)
barg pressure unit (=100 kP or 0.987 atm) gauge
°C degrees Celsius
°F degrees Fahrenheit
DC direct current
dp dew point
EU European Union
3
g/m
HCdp hydrocarbon dew point
IEC International Electrotechnical Commission
kg kilogram
lb pound
lbs/mmscf pounds of water per million standard cubic feet of gas
m meter(s)
mA milliampere
max maximum
3
mg/m
mm millimeters
mV millivolts
Nl/min normal liters per minute
Nm3/hr normal cubic meters per hour
% percentage
ppmV parts per million by volume
psig pounds per square inch
RS232 serial data transmission standard
RS485 serial data transmission standard
RTU Remote Terminal Unit
scfh standard cubic feet per hour
temp temperature
V Volts
W Watts
Wdp water dew point
Ω Ohms
“ inch(es)
Condumax II User’s Manual
grams per cubic meter
milligrams per cubic meter
Warnings
The following general warnings listed below are applicable to this instrument. They are
repeated in the text in the appropriate locations.
Where this hazard warning symbol appears in the following
sections it is used to indicate areas where potentially
hazardous operations need to be carried out.
Where this symbol appears in the following sections it is
used to indicate areas of potential risk of electric shock.
viii 97081 Issue 29.1, July 2019
Condumax II User’s Manual
1 INTRODUCTION
1.1 General
The Condumax II is designed for continuous, automatic measurement of the hydrocarbon
dew point and water dew point of processed natural gas. It is the result of more than 30
years' experience in the supply of analyzers to the worldwide oil, gas and petrochemical
industry.
The system consists of a hydrocarbon dew-point measurement sensor cell and control
electronics housed in an Exd enclosure. An optional water dew-point measurement
sensor can be accommodated, either at the time of build or as a retro-t option. A
sample gas handling panel to prepare the gas sample prior to entry into the Condumax
II can also be supplied. The analyzer is designed to be positioned close to the process
sample point and is ATEX Directive, IECEx or cCSAus compliant for use in a Zone 1 or
2 Hazardous Area and Class I, Div 1 Hazardous Location. See marking label located on
right hand side of analyzer to identify approvals.
INTRODUCTION
The unique measurement principle of the Condumax II involves detecting the formation
of hydrocarbon condensate through a highly sensitive secondary optical eect.
A reduction in scattered light intensity is observed when a well-collimated incident
light beam is reected from a shallow, abraded, conical depression by hydrocarbon
condensate forming on the measurement surface. This measurement surface is referred
to as the Optical Surface (see Section 3.8.1). The cooling of the measurement surface
is achieved using a Peltier eect (thermo-electric) heat pump. The use of this device
enables measurements to be made down to more than 50°C below the operating
temperature of the analyzer.
The Condumax II operates on a periodic measurement cycle basis. The sample ow is
continuous until, at the start of a measuring cycle, the ow is interrupted, trapping a
sample of gas within the sensor cell until the dew point is measured.
This technique of analyzing a xed volume sample successfully de-couples thermal
mass transfer and ow eects on the observed dew point ensuring that repeatable
measurements are made to a constant level of measurement sensitivity.
1.2 System Description
The requirements for operation are a 90 to 260 V AC, 47/63 Hz power supply of 125 W
and eld communications; Modbus RTU and/or 4-20 mA. Refer to the ‘Wiring Hook-Up
Diagram’ in Appendix A.3.
1.2.1 Sample Gas Path
The Condumax II measurement system must be supplied with gas at the required
pressure via a sample gas handling panel. The hydrocarbon dew-point stream is always
included as part of the system and, as an additional option, the water dew-point stream
can be tted. Sample gas entry and exit ports pass the gas through ame arrestors
which provide the explosion proof protection.
Michell Instruments 1
INTRODUCTION
The measurement system components are housed within a cast aluminum EExd rated
enclosure. The enclosure has a screw cover incorporating a sealed window. It is
chromate primed, polyester coated in black, and provides environmental protection to
IP66/NEMA 4. An enclosure breather is tted in the form of an additional ame arrestor.
It is important that no pipe connection is made to this breather and that no restriction
is allowed to occur.
All sample wetted metallic parts are manufactured in AISI 316L stainless steel with
Viton soft parts that comply with the NACE standard MR-01-75 (latest edition). Tube
ttings are twin ferrule compression type. All electrical and gas connections are made
through the base of the enclosure. Refer to the Mounting Drawing in Appendix A.1.
The hydrocarbon dew-point ow components are as follows (refer to the ‘Flow Diagram’
in Appendix A.2):
• Flow Switch 1
Provides indication that a ow is present throughout the hydrocarbon
dew-point measurement stream.
Condumax II User’s Manual
• Hydrocarbon Dew-point Sensor Cell
Provides the measurement of hydrocarbon dew point within the sample
gas.
• Pressure Transmitter 1
Provides the measurement of the sample gas pressure within the
hydrocarbon dew-point measurement cell.
• Solenoid Valve
Enables sample gas shut o to provide xed volume measurement.
The water dew-point ow components are as follows:
• Flow Switch 2
Provides indication that a ow is present throughout the water dew-point
measurement stream.
• Pressure Transmitter 2
Provides the measurement of the sample gas pressure within the water
dew-point measurement cell.
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Condumax II User’s Manual
1.2.2 Operating Overview
At the beginning of a measurement cycle, the sample solenoid valve is closed to trap a
gas sample in the hydrocarbon sensor cell for analysis and the controlled cooling of the
optical surface commences. When the scattered light intensity, measured by the optical
measurement system, reaches a user-set trip point, the temperature of the optical
surface is recorded as the hydrocarbon dew point. After this, the sample gas ow is
restored and the optical surface is heated to the temperature set-point. The heating of
the optical surface to an elevated temperature ensures that any hydrocarbon residue is
released from the optical surface before the next measurement cycle.
This measurement process is repeated cyclically at intervals determined by the control
system and pre-set by the operator. The minimum cycle time is 10 minutes and under
ideal conditions, when the condensate formed is suciently volatile to evaporate the
residue, the recovery phase will be approximately 8 minutes. However, in applications
where relatively high hydrocarbon dew points occur (within 10°C of saturation at the
sampling system temperature) then longer cycle times may be required in order to
avoid residue build-up on the optical surface.
The measurement of the water dew point is continuous and the gas sample ow is
uninterrupted.
INTRODUCTION
The measured hydrocarbon and water dew-point temperature, pressure, date and
time are stored and indexed in the memory, with the most recent reading logged as
number 1. The temperature and pressure readings are available via both the digital
and analog communications. The date and time are only available through digital
communication.
1.2.3 Condumax II User Display and Interface
The Condumax II User Display and Interface Unit is presented via the circular window
of the enclosure. Operation is achieved by a unique system which allows full control
through the glass of the enclosure cover. The cover is fully detachable for greater
access into the enclosure during the installation and initial set-up of the instrument.
During normal operation of the instrument the cover must remain fully secured.
1.2.4 Calibration
The Condumax II is factory-tested and calibrated prior to delivery. Certication is provided
for the hydrocarbon dew-point sensor and the optional water dew-point sensor, if tted.
The hydrocarbon dew-point sensor is calibrated at three points across its operating range
using a certied gas mixture of 10% (mol) n-butane in pure nitrogen. The calibration gas
is a gravimetric mixture produced using weights traceable to National Physical Laboratory
(NPL). Calculation of the relationship between calibration gas pressure and hydrocarbon
(n-butane) dew-point temperature is determined using the Peng/Robinson equation of
state. The sensor is also performance tested against samples of synthetic natural gas,
to conrm the correct optical response to multiple condensable components. These
speciality gas mixtures are analyzed by a UKAS accredited laboratory in accordance with
BS EN ISO 17025.
The water dew-point sensor is supplied with its own Calibration Certicate, providing
direct traceability to both UK (NPL) and US (NIST) Humidity Standards. The sensor is
certied at 7 dew-point levels across its operating range against a certied reference
hygrometer, using a mass-ow humidity generator system as a source of reference
calibration gas (refer to Section 4.1 for details on calibration maintenance).
Michell Instruments 3
INTRODUCTION
Condumax II User’s Manual
1.3 Condumax II Analyzer Storage Instructions
The Condumax analyzer has been designed for the accurate measurement of hydrocarbon
and water dew point within natural gas. In order for the analyzer to be functional upon
installation it should be stored in accordance with the guidelines below:
• The analyzer must be housed in a sheltered area, out of direct sunlight
and rain.
• The analyzer should be stored to minimize the possibility of sitting in
ground water.
• The temperature within the storage environment should be maintained
between 0 and +50°C (+32 and +122°F).
• The humidity within the storage environment must be non-condensing.
• The storage environment must not expose the analyzer to any corrosive
elements.
• The analyzer may stay assembled with its sample conditioning system (if
supplied).
• All electrical and process connections should remain disconnected.
• All protective coatings should remain in place until installation.
• For prolonged periods of storage, the lid of the packaging crate should be
removed to allow air to circulate.
• The documentation supplied with the analyzer should be removed from
the packaging crate and stored elsewhere to protect its integrity.
For the period from installation of the Condumax II analyzer to commissioning start-up,
the following precautions should be followed:
• The analyzer and associated sampling system must remain isolated from
the process gas, and the enclosure should remain closed to ensure ingress
protection is maintained.
• The sampling system enclosure heating/thermostat circuit should be
operated if the climatic temperature might fall below 0°C (+32°F).
• At time of start-up the procedures contained in the User Manuals for both
analyzer and sampling system must be followed.
If the Condumax analyzer was previously in service/operation then the following
precautions should be followed before storage:
• Upon isolation from the gas sample the entire system should be purged
with a dry nitrogen gas before powering down of the analyzer.
• All connections and ports (gas and electrical) to the analyzer or sample
system (if provided) should be capped.
• If the analyzer is not removed from its location, the electrical grounding
of the analyzer should remain in place.
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2 INSTALLATION
2.1 Electrical Safety
During the installation of this product ensure that all
applicable national and local electrical safety regulations
Always ensure that power is switched o prior to accessing
the product for any purpose other than normal operation or
INSTALLATION
WARNING:
are observed.
WARNING:
Isolate the power prior to installation.
WARNING:
prior to disconnecting any cables.
2.1.1 Equipment Ratings and Installation Details
The following mandatory statements refer to the Ex certied Condumax Analyzer only
(not including the sampling system).
This equipment must be supplied with a voltage between the range of 90 to 260 V AC,
47/63 Hz. Maximum power rating is 125 W.
The power is connected via PL1 on the mains connector PCB.
Figure 1
All input and output connectors are 2-part PCB mounted type, rated at 300 V 10 A.
The detachable, screw terminal half of each connector is designed to accept 0.5 to
2.5mm2 [24 -12 AWG] stranded or solid conductors.
Power Connection Connector
Michell Instruments 5
INSTALLATION
Any power connection cable should be 3 core over sleeved, with minimum 0.5mm
insulation and rated at 300 V. Cables should have Live (L), Neutral (N) and Earth
[Ground] (E) conductors. Ensure suitably rated power supply cables and glands are
used to ensure that electrical safety is maintained. Connect each of the Live (L), Neutral
(N) and Earth [Ground] (E) conductors to the similarly marked terminals (L, N, E) on the
Power In connector shown in Figure 1. Ensure the power supply can deliver sucient
power consumption requirement.
Any power supply terminals and voltages must be suitably separated from the other I/O
requirements of this product.
Before applying power, perform a continuity test to ensure that the power supply cable
and product are eectively connected to the protective Earth.
The Protective Earth terminal is mounted internally and the Earth wire connected to it
should never be disconnected. The product enclosure is supplied with an external earth
stud at the lower right hand side. At installation, connect this earth stud to plant earth
by a minimum 4mm2 earthing bonding. M6 stud and 2 o M6 nuts and washers, all
nickel plated.
Condumax II User’s Manual
Figure 2
Fuse: A replacement fuse can be obtained by contacting Michell Instruments' technical
support. Fuse rating = 5 x 20mm 2.5 A anti-surge to IEC 60127-2.
This product is designed to operate, as a minimum, between a temperature range of -40
to +60°C, in maximum 80% relative humidity for temperatures up to +31°C decreasing
linearly to 50% RH at +50°C. Supply voltages of ±10% and transient over voltages
up to Overvoltage Category II. Pollution Degree 2. Altitudes up to 2000m. Outdoor
mounting is permitted using suitably rated glands equivalent to NEMA 4 / IP66. See
Appendix A, Technical Specication for full operating parameters.
Do not remove or exchange any of the cables or electrical components supplied with
this product. Doing so will invalidate all warranties.
There are no additional or special electrical safety requirements other than those
referred to in this manual.
Earthing Stud And Nut Washer Assembly
6 97081 Issue 29.1, July 2019
Condumax II User’s Manual
Location and mounting arrangements - refer to the relevant sections of this manual for
the location and mounting details.
Installation of this equipment must include the provision of a suitable and locally
positioned power isolation switch or circuit breaker. Indication of the purpose of the
switch or circuit breaker is strongly recommended. An over-current protection device
should be rated to a maximum of 10 A.
This equipment and all power isolation devices must be installed in a location and
position that allows safe and easy access to their operation and is able to rigidly support
the equipment.
Do not install this equipment in a location that would expose it to impact or high levels
of vibration.
Operation of this equipment, other than in a manner specied by the manufacturer, may
impair the safety protections provided.
The safe installation of this equipment and any system incorporating this equipment is
the responsibility of the installer. Ensure local regulations and requirements are referred
to prior to any installation commencing.
INSTALLATION
Michell Instruments 7
INSTALLATION
!
2.2 Hazardous Area Safety
Refer to Appendix G for the Hazardous Area Certication of this product.
This product is tted with a marking label that contains Hazardous Area information
pertinent to the suitable location and installation.
During all installation and operation activities, local regulations and permitted working
routines must be observed. Installation should only be performed by competent personnel
and in accordance with the latest version of IEC/EN60079-14 or local equivalent.
Repair and servicing of this equipment must only be carried out by the manufacturer.
An Installation and Maintenance Information Sheet is supplied separately to the manual.
This product is certied safe for use in a Zone 1 and Zone 2
area only. This product must not be installed or used within
Condumax II User’s Manual
WARNING:
a Zone 0 area.
WARNING:
This product must not be operated within an explosive
atmosphere greater than 1.1 bara.
WARNING:
This product must not be operated with enriched oxygen
gas samples (more than 21% oxygen content).
WARNING:
This product must not be operated outside of the
temperature range of -40 to +59°C (-40 to +138°F).
WARNING:
The enclosure of this product provides Exd protection, partly
through the threads used for mounting the lid, stopping
plugs and cable gland. At all times eort should be made to
ensure these threads are suitably protected from damage
and that only appropriately rated mating parts are applied
to them, in accordance with the certifying requirements.
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2.3 Pressure Safety
This product is used in conjunction with pressurized gases.
Observe pressurized gas handling precautions.
Pressurized gas should only handled by suitably trained personnel.
INSTALLATION
WARNING:
WARNING:
Pressurized gas is dangerous.
This product requires pressurized gas to be connected to it. Observe pressurized gas
handling regulations. Only suitably trained personnel should carry out tasks that include
the use of pressurized gas mediums.
2.4 Lifting and Handling
Personnel must observe suitable lifting and handling precautions.
This product is not designed as portable or transportable equipment. It should be rigidly
xed in position as per the full installation instructions.
The weight of the analyzer is in excess of 18kg (40lbs). Therefore, appropriate lifting and
handling techniques should be used during the installation process. Before commencing
any lifting or handling ensure that its intended location is suitable and appropriately
prepared. Make sure that mounting point design considerations have employed locally
approved safety factors.
WARNING:
This instrument is in excess of 18kg (40lbs).
When handling and installing this product (particularly after removal from its packaging)
ensure that it is not dropped, impacted or subjected to high levels of vibration or
environmental conditions that may impair its operation.
Michell Instruments 9
INSTALLATION
2.5 Measurement System
Refer to the Installation & Maintenance Information sheet (supplied separately) and the
System Drawings in Appendix A.
The instrument is housed in an aluminum EExd enclosure suitable for wall or panel
mounting. Four mounting points are available with M12 clearance holes on xing centres
of X = 270mm (10.62") x Y = 318mm (12.51").
The dimensions of the enclosure are:
Height: 355mm (13.9”), 500mm (19.68”) including installation clearance
Width: 310mm (12.20”), 500mm (19.68”) including installation clearance
Depth: 245mm (9.64”)
The enclosure provides environmental ingress protection IP66/NEMA 4 and should be
mounted vertically in a location free of any appreciable vibration. It should be placed in
a shaded position to prevent heating eects through sun radiation.
Condumax II User’s Manual
The weight of the analyzer is 25kg (55lbs).
245mm 9.65"
290mm [11.41"]
Water Dew-Point Channel
1/8" NPT Female (ATEX/IECEx/CSA)
Hydrocarbon Dew-Point Channel
1/8" NPT Female (ATEX/IECEx/CSA)
Flame Arrestor
Flame Arrestor
270mm 10.63"
4 off M12 (1/2")
Clearance
318mm 12.52"
Enclosure Breather
Flame Arrestor
Do NOT obscure
Hydrocarbon Dew-Point Channel
Flame Arrestor
1/8" NPT Female (ATEX/IECEx/CSA)
Water Dew-Point Channel
Flame Arrestor
1/8" NPT Female (ATEX/IECEx/CSA)
Cable Entry Glands
3 off M20 (ATEX)
3 off M20 -> 1/2" NPT Thread Adaptor (CSA)
Figure 3
310mm [12.20"]
Condumax Dimensions
10 97081 Issue 29.1, July 2019
Condumax II User’s Manual
FLOW
FLOW
PRESSURE
PRESSURE
GAS SAMPLING BLOCK
HYDROCARBON
DEW-POINT
SENSOR CELL
MICHELL WATER
DEW-POINT SENSOR
GAS IN
GAS IN
GAS OUT
GAS OUT
FLAME
ARRESTORS
FLAME
ARRESTORS
SOLENOID VALVE
TRANSMITTER
TRANSMITTER
SWITCH SWITCH
MAX. 138/206 BARG MAX. 100 BARG
ENCLOSURE BREATHER
(DO NOT OBSTRUCT)
1
12
2
2.5.1 Gas Connections, Sample Extraction & Conditioning
INSTALLATION
NOTE: Ensure that the process sample gas supply line is well ushed through
to clear any liquids and debris present prior to connection to the instrument. A
sample handling system must prepare the gas in terms of pressure regulation
and ltration before entering into the measurement system.
The pipe work connections are as follows:
Figure 4
Flow Schematic
In accordance with the certication requirements for safe
operation of this product, the Condumax II must have, as a
minimum, those components described in Section 2.7 and
Hydrocarbon gas sample inlet
positioned as shown in Appendix A.1.
(Maximum pressure of 100 barg (1450 psig))
Hydrocarbon gas sample outlet
(Vent to atmosphere or low pressure flare line)
Water dew-point gas inlet
(Maximum pressure of 138 barg (2000 psig))
Water dew-point gas outlet
(Vent to atmosphere or low pressure flare line)
1/8" NPT Female
(ATEX/IECEx/
CSA)
Michell Instruments 11
INSTALLATION
The following points should be considered when installing the sample gas supply line:
PTFE tape is recommended for pipe connections. Solvent based pipe thread sealant
should not be used, as condensable components or contaminates can be leached during
the curing period.
It is recommended that Viton is used for all O-rings.
Care and attention to the position and installation of the piping will minimize problems
caused by avoidable contamination of the measurement system. The most common
cause of diculty is the accumulation of liquid in impulse lines during a shutdown
period. If the measurement system has not been isolated on restart-up, condensate
can be displaced into components and associated pipe work within the measurement
system.
If this event follows a period when process lines may have been contaminated by nonhydrocarbons e.g. glycol, corrosion inhibitors etc., the problem is magnied. Similarly,
diculty will be encountered in sample gases carrying liquids, including hydrocarbon
liquids.
Condumax II User’s Manual
Our recommendations are:
• The sampling point on the process line should be on the top of the pipe.
If a radial probe is used the orice should face downstream.
• The internal volume of the impulse tubing between the process line and
any sampling system should be as low as possible to minimize response
lag time to changing process conditions.
• Piping should be lagged and/or trace heated if ambient temperatures
could cause the sample gas to fall below its dew-point temperature.
• A drain valve should be placed at the low point (if any) in the system.
• It should be standard procedure to isolate the measurement system
during shutdowns or when plant problems are being experienced and to
properly purge the supply lines before restarting.
• The relatively large area of surfaces and internal volume of pressure
regulators can be particularly troublesome if contamination is experienced.
Prolonged purging with gas may be necessary to remove the contamination.
Stripping and cleaning followed by purging of the system is preferred.
• Avoid sample gas streams that are already very close to the dew point
or which have dispersed liquid (not necessarily hydrocarbon) burden. In
such cases, sampling from fast loops and/or from downstream of existing
catch pot/coalesce systems is always preferred.
Failure to observe these recommendations will potentially cause problems of
contamination as well as causing consequential inaccurate, unreliable and inconsistent
monitoring. If a top-entry sample point is not available, extra attention should be given
to the design of the sample line installation to avoid unwanted contamination.
12 97081 Issue 29.1, July 2019
Condumax II User’s Manual
Sample Extraction and Conditioning
Sample extraction, handling and conditioning techniques are of critical importance
to assure optimal performance and reliability of all gas analyzers which accurately
quantify specic components within a process gas composition. Michell Instruments'
recommendations and requirements in relation to the Condumax II are outlined below.
Michell Instruments oers a range of sample conditioning systems which are designed to
exceed these minimum requirements. For further information and advice please contact
your local Michell oce or distributor – See contact details on www.michell.com.
Sample Extraction and Impulse Tubing
An insertion probe, with tip positioned within the central 1/3rd of the cross sectional
area of the pipe, should be used to derive a sample composition that is representative
of the majority of gas owing within the pipeline.
Attention should be given to the installation of impulse tubing connecting from sample
probe to the analyzer sample conditioning system. Analytical grade acid-etched
stainless steel tubing should be used, which has a low moisture sorption capacity. Tube
size should not be larger than ¼” or 6mm outside diameter to ensure that sample
transportation delay time is kept to a minimum. Likewise, to ensure best dynamic
response of the complete installed analyzer system, the positioning of the analyzer with
sample conditioning system should be as close as possible to the sample extraction
probe.
INSTALLATION
To avoid any risk of condensation forming during transportation to the analyzer, and so
ensure the integrity of the sample gas is maintained, the temperature of the sample
impulse tubing must be maintained at a temperature above the highest envisaged
water dew point. It is recommended that the sample tubing temperature is maintained
at least 5°C (10°F) above the maximum water dew point at the prevailing pressure, as
a suitable ‘safety margin’. Self-limiting heating cable should be applied to the complete
length of the impulse tube, enclosed within suitable insulation. The power rating of
heating cable should be selected to achieve the required maintained temperature given
the minimum climatic temperature at the installation location. For convenience during
installation, a number of leading process electric heating companies oer tube ‘bundles’
comprising instrumentation tubing, self-limiting heating cable, insulation and protective
outer sheath. Trace heated tube bundle is a factory tted option for Michell produced
sample conditioning systems.
Sample Conditioning
The sample conditioning system must address the needs for ltration, pressure reduction
and sample ow control.
To maintain cleanliness of the analyzers optical detection system, the process sample
ow must be ltered to eliminate entrained liquids and particles. To provide protection
against HC condensates and compressor oils that may be present in process natural
gas, it is recommended to use micro-porous membrane ltration with an oleo-phobic
element specically intended to reject such low-surface tension liquids.
Michell Instruments 13
INSTALLATION
Pressure reduction and sample ow control is required to achieve the desired analysis
pressures and the stated sample ow requirements of the analyzer – see Section 2.7.
Care should be taken to counteract though directly applied heating the Joule-Thomson
cooling eect of sample expansion to reduced pressure. Established business practice
at custody transfer is to measure water dew point at full line whilst HC dew point is
determined at intermediate pressure, commonly 27 barg (400 psig), the cricondentherm
condition at which HC dew point temperature will be highest on the retrograde phase
envelope – see gure below:
Condumax II User’s Manual
H2O Dew Point
8
7
6
5
Water and
4
HC liquids
3
2
1
0
preset in
gas
-30-40 -20 -10 0 +10
Pressure MPa
HC liquids
present in
gas
HC Dew Point
Wholly gaseous
Cricondentherm
Temperature °C
Figure 5
Typical Phase Envelope for Northern Europe Natural Gas
As with the sample impulse tubing, the sample conditioning system (SCS) must be
maintained at a temperature above the highest expected water and HC dew point at
the prevailing process sample pressure and the analysis pressure for HC dew point,
either by housing the SCS together with the analyzer within a heated and thermostatic
controlled, insulated enclosure, or by positioning in a suitable indoor environment. The
enclosure for outdoor installed systems must be located within 100% shade from direct
sun, if necessary by the addition of an eective sun canopy with walls on three sides.
As with all precision analytical equipment, it is desirable to maintain a moderate operating
temperature. In the specic case of a HC dew-point analyzer, care should be taken not to
elevate the analyzer operating temperature higher than is necessary to maintain sample
integrity. Given the principle of cooled-mirror dew-point measurement, the measurement
range of HC dew point is limited by a cooling depression range capability. In the case
of the Condumax II, the lower range capability is >=50°C from the prevailing analyzer
operating temperature. When the analyzer system is installed outside in hotter climate
installation locations, or where the application requires measurement near or below the
measurement cooling depression limit, it may be necessary to provide auxiliary cooling
within the system enclosure. Such cooling can be achieved using a compressed air
driven vortex tube controlled by an adjustable thermostat.
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Condumax II User’s Manual
2.5.2 Power Connection
A single-phase AC power connection is required.
The power supply can accommodate voltages from 90 to 260 V AC, 47/63 Hz. The unit
requires a maximum of 125 W to function correctly.
Cable entry into the measurement system is made through the bottom of the enclosure.
• For ATEX/IECEx compliant versions of the product 3 o ISO M20 tapped
holes are provided.
• For CCSAUS compliant version of the product 3 o M20 -> 1/2" NPT thread
adaptorare provided.
Power connections are made via a removable screw terminal connector mounted on the
mains connection PCB.
INSTALLATION
Terminals are marked:
L = Live
N = Neutral
E = Earth/Ground
Power supply
connector
0VAB
1 2 3 4 5 6 7
mA2-
L E N
mA2+
mA1-
mA1+
COMMS connector
Foil screens
fold back
to gland
Earth/Ground
Barrier gland
Braided screen
Gland
Earthing/Grounding
Collar
Connecting cable to be
compliant with
Special Conditions for Use
stipulated within the
ATEX & IECEx Certificates
Figure 6
Wiring Hook-Up Diagram
Michell Instruments 15
INSTALLATION
2.5.3 Analog and Digital Communications
Two active 4-20 mA outputs and a Modbus RS485 digital interface (see Appendix B for
details) are provided with the Condumax II. The 4-20 mA outputs can be set individually
to represent one of the following:
• Hydrocarbon dew point (or signal in mV if in condensate mode)
• Hydrocarbon dew-point analysis pressure
• Water dew-point analysis pressure
• Water dew-point temperature (or moisture content)
NOTE: The maximum output resistance for the 4-20 mA outputs is 500 Ω.
Condumax II User’s Manual
Refer to Section 3.10.4 for the setting of the 4-20 mA outputs via the user interface and
refer to Appendix B.4 on setting the outputs via the Modbus interface.
16 97081 Issue 29.1, July 2019
Condumax II User’s Manual
2.6 Condumax II Start-Up Purge Procedure
This is a mandatory procedure stipulated in the ATEX/IECEx
certication of the product. The procedure must be fully
carried out prior to the Condumax II having any power or
signal connections applied. It must also be fully carried
out after the Condumax II and associated gas handling
equipment has been installed and leak checked. Always
refer to Appendix G.4 - Special Conditions of Safe Use.
This procedure must be carried out at any time following
service or maintenance periods that cause any of the
Condumax II or associated gas handling equipment pipe
work to be disconnected.
It is not necessary to carry out this procedure if power or
signal connections only, have been disconnected.
INSTALLATION
1. Before start-up, ensure that all power and signal connections to the
Condumax II are fully isolated.
2. Ensure that all inlet & outlet gas connections to the Condumax II are
correct and leak tight checked.
3. Fully open the ow control valve of the owmeter on the hydrocarbon
dew-point channel and, if also tted, the water dew-point channel.
4. Set the solenoid valve to the PURGE position (fully screwed in clockwise)
by using the manual override operating adjuster mounted on the
base of the solenoid valve body. Indication of the manual override position
is shown on a label attached to the solenoid Access to the solenoid valve
is obtained by removing the enclosure cover. Refer to Section 4.2 for
removal and retting of the enclosure cover.
The manual override operating adjuster is provided
only to allow initial system set-up and purge in an
unpowered condition. This manual override adjuster
must never be operated while in a pressure induced
condition. The manual operation of the valve is not
required for the normal operating cycle of the system.
5. Fully open the sample gas inlet isolation valve.
6. Gradually open the pressure regulator until full scale ow is observed on
the hydrocarbon dew-point channel owmeter and the water dew-point
channel owmeter, if tted.
Michell Instruments 17
INSTALLATION
HYDROCARBON
DEW-POINT
CHANNEL
WATER DEW-POINT
CHANNEL
GAS IN GAS OUT
GAS IN GAS OUT
CONDUMAX II
See NOTE 2
FLOWMETER
FLOWMETER
NON-RETURN
VALVE
GAS OUTLET
GAS INLET
ISOLATION VALVE
PRESSURE
GAUGE
PRESSURE
REGULATOR
GAS INLET
NOTE:
1. Connecting pipework to be 4mm I/D bore, 316L stainless steel tube
2. Components and pipework only required if water dew-point channel is installed into Condumax
See NOTE 2
7. Allow the sample gas to purge the system for the period of time indicated below:
• Total purge time must be a minimum of 1 minute at 1 Nl/min (0.06
• For every additional meter of 4mm internal bore pipe work of a
8. After the appropriate purge duration the gas inlet isolation valve may be closed.
9. Return the manual override valve adjuster on the Solenoid to the NORMAL
OPERATING position (fully unscrewed counter-clockwise).
10. The enclosure cover may now be replaced. NOTE: Before any power or signal
lines are connected the enclosure cover must be fully tted.
11. After the enclosure cover has been retted the Condumax II is ready for immediately
start-up. NOTE: If start-up is delayed then the purge procedure must be
repeated.
Condumax II User’s Manual
Nm3/hr) (2.1 scfh).
Assumes total system (see diagram below) pipe length is 3m (9.8ft)
and internal pipe bore is the recommended 4mm internal bore.
sampling system, continue the gas purge for an additional 15
seconds at 1 Nl/min (0.06 Nm3/hr) (2.1 scfh).
Figure 7
Minimum Requirements for Start-Up Purging
2.7 Sample Gas Flows
The sample gas ows for the system should be set as follows:
• For the hydrocarbon dew-point channel it is recommended that a ow of
approximately 1 Nl/min (0.06 Nm3/hr) (2.1 scfh) is set. This ow setting
gure is not required to be precise as its purpose is only to ensure that
18 97081 Issue 29.1, July 2019
a representative sample of gas is presented to the measurement sensor.
During the measurement cycle the sample gas ow is isolated as the
measurement is made in a static ow condition.
Condumax II User’s Manual
• To increase the speed of response of the measurement of the main
process gas it is highly recommended that a fast bypass loop is installed
into the gas sampling system. The recommended ow through the bypass
loop should be typically 3 to 4 times that of the hydrocarbon channel.
Therefore, typically, the bypass gas ow should be set to approximately 3
to 4 Nl/min (0.18 to 0.24 Nm3/hr) (6.3 to 8.5 scfh).
• If a water dew-point channel is tted, the gas ow through its sensor
should be set at approximately 3 Nl/min (0.18 Nm3/hr) (6.3 scfh).
2.8 Sample Flow Alarms
The ow switches are supplied to alert the user to either
severely reduced or discontinuation of sample gas ow
INSTALLATION
through the system.
An alarm state will be indicated on the Error Message line at the bottom of the MAIN
display. Refer to Section 4.6 for further details.
After the correct ow of sample gas is set, the alarm states will be indicated when the
gas ow has fallen below that required to make eective measurements.
The ow switches tted are adjusted during factory test to activate the alarm when
the ow falls below approximately 20 to 10% of the normal recommended sample ow
setting (see Section 2.7). During the factory setting procedure the gas pressure that is
applied represents the most common application analysis conditions for hydrocarbon
(27 barg (391 psig)) and water (68 barg (986 psig)) dew-point sensors.
The operation of these variable area ow switches are inuenced by pressure. For
increased pressure the ow alarm activation point will be at a higher ow rate and
conversely, for reduced pressure, the activation point will be at a lower rate. These
devices exhibit a hysteresis that may require a ow of greater than 100% of the
recommended ow setting for a brief period in order to clear the alarm condition.
NOTE: If the Condumax II main unit is going to be operating with signicantly
dierent analysis pressures to those used during factory testing, then ne
re-adjustment of the ow switches may be benecial to suit the application
conditions. If this is the case contact Michell Instruments (www.michell.
com) for guidance as to how adjustments can be made on site.
Michell Instruments 19
OPERATION
3 OPERATION
At switch-on, the system synchronizes to the on-board real-time clock, heats the optical
surface to the set-point temperature and adjusts the optical levels to give a signal
level of 0.00%. When the ‘next measurement’ time counts down to 0 minutes and 0
seconds, the measurement cycle commences and the system cools the optical surface
at a controlled rate until the signal level increases to 100% of the trip point. Once
reached, the optical surface temperature is recorded as the hydrocarbon dew point,
along with the hydrocarbon channel pressure, water dew point (if this option is tted)
and water channel pressure. The optical surface is then heated to the set-point and
the optics level is re-adjusted to give a signal level of 0.00%. The cycle is repeated
continuously at ‘cycle time’ intervals, which are factory set at 10 minute intervals but
may be user adjusted.
3.1 Timing Synchronization
At switch-on, the instrument will display the MAIN page (Section 3.6) and synchronize
itself to the on-board real time clock, in order to start the measurement cycles at a
time (hrs:mins) that is divisible by 10 - i.e. 10, 20, 30, 40, 50 or 60 (0). If the rst start
time is less than 2 minutes away, then the system will start measurements on the next
permissible start time. For example, if the instrument is switched on at 6 minutes past
the hour, then the instrument will take its rst measurement at 10 minutes past the
hour. However, if the instrument is switched on at 9 minutes past the hour, then the rst
measurement will begin at 20 minutes past the hour, to ensure there is enough time for
the system to auto-calibrate itself.
Condumax II User’s Manual
3.2 Recovery Phase
Auto-calibration commences at switch-on and after every measurement cycle. The
sensor mirror is heated to the mirror temperature set-point and the optics level is
adjusted to give a signal level of 0.00%. This procedure is shown on the STATUS Page
where the mirror temperature, signal and optics values can be observed.
3.3 Measurement Phase
The Condumax II can be set to function in one of 2 modes - Condensate Mode and
Measurement Mode are mutually exclusive. One is the inverse of the other.
Measurement Mode: HC dew-point temperature at a set trip point (threshold for
signal change, mV). This is the normal operating mode for the analyzer.
Condensate Mode: Signal change (mV) at a customer set cooling trip temperature.
This mode can be applied temporarily by the user if harmonization of HC dew-point
temperature measurement sensitivity to a desired reference value is required. As an
example, the Trip Temperature could be set to the user's reference HC dew point
temperature in order to determine, through a series of Condensate Mode measurements,
the Signal Change 9mV0 setting required in order for Condumax II to replicate the same
measured value in normal Measurement Mode operation. For further information refer
to section below.
• Measurement Mode
When the phase duration time reduces to 0 minutes and 0 seconds, as
shown in the bottom line of the MAIN and STATUS Pages, the system will
deactivate the internal sample solenoid valve to stop the gas sample ow and
reduce the temperature of the mirror at a controlled rate until the signal level
has increased to 100% of the signal level trip point (refer to Appendix D.1).
Once this detection threshold is reached the optical surface temperature will
be reported as the HCdp.
20 97081 Issue 29.1, July 2019
Condumax II User’s Manual
During every measurement cycle, and based on the previous measurement,
the optical surface temperature ramp rate is optimized to be at 0.05°C/sec
at the point of hydrocarbon dew-point measurement.
After the signal trip point has been reached, the system will re-enter the
Recovery Phase, control the temperature of the optical surface to the
set-point, adjust the signal level to 0.00% and count down to the next
Measurement Phase.
• Condensate Mode
When the phase duration time reduces to 0 minutes and 0 seconds, the
system will deactivate the internal solenoid valve and cool the optical surface
at a controlled rate until the the user set trip temperature is reached. This
mode provides a method to observe signal change to a dened temperature
(user-set trip temperature - refer to Appendix D.1), whereby the change in
optical detection signal is recorded and displayed in mV.
The duration of the Recovery Phase in both modes is dependant upon the time taken to
reach the trip point or temperature and the duration between measurements. Typically,
for factory-default 10 minute cycle time, the measurement cooling duration is 2 to 3
minutes with the remaining 8 to 7 minutes Recovery Phase.If the system does not reach
the trip point or temperature, then the system will re-enter the Recovery Phase after
the maximum cooling time has expired.
OPERATION
3.3.1 Water Dew-Point Measurement
If a water dew-point sensor is tted, the instrument will detect its presence at switch-on
and display both water and hydrocarbon dew point and pressures as shown in Section
3.12. The water dew point and water dew-point pressure readings are updated at 1
second intervals.
3.3.2 Signal Changes and Trip Point
The measurement circuits within the instrument are very sensitive and are capable of
sensing ųV changes in the optical detection circuit. When condensate forms on the
optical surface of the sensor, the received light level progressively falls and is seen on
the status page as an increase in signal change This is dened as sensor optical surface
wet-out. The smallest detectable signal changes can be regarded as the inception
of condensate formation. However, for mixed hydrocarbon gas streams where a tail
of heavy components is present, this initial change is of little signicance since the
amounts of condensate are minute and are often undetectable by sensitive chemical
analysis methods such as gas chromatography.
The magnitude of the change in the optical detection circuit is a function of the quantity
of condensate formed on the sensor surface. Therefore, a signal change threshold can
be set which corresponds to some signicant condensate quantity; this threshold level is
referred to as the ‘trip point’. A ‘trip point’ value can be selected to produce a measured
dew-point temperature which agrees with the value predicted by the extrapolation of
the linear regression plot of liquid/gas ratio (LGR as a function of temperature) to zero
condensate for the gas stream under test.
Michell Instruments 21
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