CONTHOS 3 - PMD
Paramagnetic Oxygen Gas Analyzer

Features and typical applications
Description
Model variations
Technical data
Downloads

Paramagnetic oxygen measurement - 19“ & field housing O2 process gas analyzer – CONTHOS 3 - PMD

Typical Applications

  • Fast response process gas measurement
  • Flue gas control analyzer
  • Inertization plants
  • Biogas O2 measurement
  • Air separation, O2 gas purity
  • Power plants, metallurgical, chemistry, petrochemistry

Key Features

  • Oxygen specific analysis utilizing paramagnetic sensor
  • Magnetomechanical measuring principle (dumbbell principle)
  • Temperature controlled for increased stability and performance
  • Up to 3 measuring ranges
  • Optional paramagnetic cells for corrosive gases and solvents
  • Optional intrinsically safe measuring cell for flammable gases

Description

The CONTHOS 3 PMD state-of-the-art process gas analyzer is an analytical instrument developed for use in process industry.

Some of the outstanding technical features of LFE's 3rd generation, microprocessor-controlled gas analyzer for oxygen analysis are:

  • Temperature controlled paramagnetic sensor
  • Magnetomechanical measuring principle ("dumbbell" type)
  • High selectivity to O2
  • Fast response time: time constant < 5 sec
  • Excellent precision and outstanding performance for ranges from 0 - 1 vol.% O2 up to 0 - 100 vol.% O2
  • Optional automatic pressure compensation
  • Intuitive user-interface based on NAMUR recommendations
  • Automatic self-diagnosis
  • Optional paramagnetic cells for corrosive gases and solvents
  • Optional intrinsically safe measuring cell for flammable gases

 

Oxygen sensor

The basic measuring principle of the CONTHOS 3 PMD makes use of the fact that oxygen has a paramagnetic susceptibility that is significantly greater than other gases. This property causes oxygen molecules to be attracted much more strongly into an inhomogeneous magnetic field than other gases.

The paramagnetic sensor employed in the CONTHOS 3 PMD is of the so-called "dumbbell" type utilizing the magnetomechanical measuring principle. Two miniaturized, nitrogen filled gas spheres configured in a dumbbell shape are symmetrically suspended in a strong, inhomogeneous magnetic field. Any oxygen contained in the surrounding (sample) gas is drawn into the magnetic field thereby displacing the glass spheres and forcing the dumbbell to rotate outward. The resulting torque is proportional to the oxygen concentration.

A mirror mounted on the rotational axis of the dumbbell reflects a beam of light onto a pair of photocells which detect any rotational displacement. The photocells are part of a control loop which subsequently drives current through windings arranged around the dumbbell. The current through the windings generates an electromagnetic counter moment which moves the dumbbell back to its null position. The required current level is proportional to the oxygen concentration and as such is passed on to the CONTHOS' signal processing unit.

Paramagnetic O2 sensor using magnetomechanical measuring principle – "dumbbell" type

Model variations

CONTHOS 3E - PMD
19“ rack housing for cabinet mounting – absolute and suppressed oxygen ranges - CONTHOS 3 - PMD
19"-rack housing
 
CONTHOS 3F - PMD
IP65 field housing - absolute and suppressed paramagnetic oxygen ranges - CONTHOS 3 - PMD
Field housing
(protective class IP65)

Options

  • Maximum 3 switchable ranges: independently configurable; suppressed ranges as special solution on request
  • Automatic pressure compensation (from 800 to 1200 mbar absolute; extended pressure range on request)
  • Digital I/O board for remote range switching, threshold contacts, etc.
  • RS-485 interface with Modbus RTU protocol
  • Interference correction in conjunction with external, selective gas analyzers for multiple gas constituents

Technical data

 CONTHOS 3E PMD
19” rack housing
CONTHOS 3F PMD
Field housing

Technical specifications subject to change without notice

  19“ rack housing paramagnetic oxygen detector to analyze 0 – 1% O2 up to 0 - 100% oxygen Purgeable wall mounting housing paramagnetic oxygen detector to analyze 0 – 1% O2 up to 0 – 100% oxygen
Enclosure & electical data
Housing 3HE/ 84TE housing
for mounting in 19" cabinet
purgeable steel housing for wall mounting;
with separate compartments for the electronic components
and the analytical components
Dimensions
(H x W x D)
3HU / 84TE
133 x 483 x 427 mm
434 x 460 x 266 mm
Weight approx. 10 kg approx. 25 kg
Power requirements 100-240 VAC (48-62Hz; nominal voltage range: 88-253 VAC; 100 VA max. during warm-up period)
Sample gas connectors Standard: Swagelok® (SS 316) for tubing o.d 6 mm
Option: Swagelok® (SS 316) for tubing o.d. ¼"
Measuring characteristics
Measuring principle Paramagnetic sensor ("dumbbell" type)

Measured quantity
Gas interference

Oxygen concentration in gas mixtures
Note: Although the paramagnetic susceptibility of O2 is much greater than other gases, these can also exhibit lower degrees of paramagnetic susceptibility and therefore as interfering components possibly influence the accuracy of the analysis. For this reason the gas matrix should be evaluated.

Measuring ranges

Up to 3 independently configurable, switchable ranges.
Suppressed ranges as special solution on request.
Range switching is accomplished manually, automatically and/or remotely (via optional digital inputs).

  • lowest range: 0 - 1% O2
  • largest range: 0 - 100% O2
Response time T90 < 5 sec (dependent upon gas flow and analyzer configuration; integration time configurable)
Influence of gas flow between 30 – 60 l/h: < 1% of range span for a gas flow change of ±10 l/h
Detection limit 1 < 1% of span
Reproducibility 1 < 1% of span
Linearity 1 < 1% of span

Response drift 1

Zero: < 2% of span per week
Span: < 1% of span per week

Ambient temperature influence

Zero: < 1% of span per 10 K
Span: < 1% of span per 10 K

Calibration Manual: 2-point (offset/span) calibration (The optimal span gas concentrations should be chosen between 75 and 100 % of the corresponding range).
Option: automatic or remote calibration in conjunction with the optional digital I/O board or RS-485
Pressure compensation optional: from 800 to 1200 mbar absolute; extended pressure range on request
Interference correction for static and/or dynamic interference correction (dynamic correction only in conjunction with the optional analog inputs or RS-485).
One of the prerequisites for dynamic interference correction is the availability of a selective signal, proportional to the particular gas component to be corrected for. The processing of analyzer ranges with a suppressed zero range is not possible.
Materials in contact with sample gas
Paramagnetic sensor platinum, epoxy, glass, FPM, stainless steel 1.4571
Sample gas connectors standard: stainless steel (SS 316)
Sample gas lines standard: PTFE
optional: stainless steel tubing (SS 321 - similar to 1.4541) and 1.4571
Data display, inputs & outputs

User interface

LC-display (40 characters x 16 lines) + bar graph
Plain text description of instrument status as well as digital status output
Language: switchable between English & German

Analog signal output

2 independently configurable, galvanically isolated analog outputs (with common ground; RLoad = 600 Ohm max)
Available output levels: 0 - 20 mA, 4 - 20 mA, 4 - 20 mA with superimposed instrument status (NAMUR NE 43 compliant) as well as test signal levels (0, 4, 10, 12 & 20 mA)

Digital outputs
1 to 3
(instrument status)

Instrument status (NAMUR NE 107 compliant) via floating contacts (28 V max.; 350 mA max.)
FAILURE (DO 1) | MAINTENANCE REQUIRED (DO 2) | FUNCTION CHECK (DO 3)

Analog inputs
(optional)
3 galvanically isolated, configurable analog inputs for interference correction and pressure compensation
0 – 20 mA or 4 – 20 mA (Ri = 50 Ohm)

Digital I/O
(optional)

Digital inputs: 8 configurable, optically isolated inputs (6 - 24 VDC; 10 mA max.)

  • remote range selection
  • remote triggering of zero and span calibration
  • remote triggering and cancelling of automatic calibration
  • switching of interference correction analog inputs to a secondary input range
  • mapping of user defined input to a digital output

Digital outputs: 7 configurable, floating relay contacts (28 V max.; 350 mA max.)

  • threshold monitoring (1 threshold per measuring range)
  • feedback as to the current range
  • calibration gas selection
  • mapping of user defined input to a digital output

(Note: The digital I/O board cannot be used in conjunction with the RS-485 serial interface hardware.)

RS-485 (optional)

with Modbus communications protocol; galvanically isolated interface
(Note: The RS-485 serial interface hardware cannot be used in conjunction with the digital I/O board.)

Service interface non-isolated serial interface for accessing the instrument's configuration

1 at constant temperature and pressure

 

  • The stability data is valid for analyzer operation with pure bottled gases. Instrument accuracy is based on binary or quasi-binary gas mixtures. Deviations from the above data can occur in conjunction with process gases depending upon the gas quality and the degree of gas handling.
  • Unless otherwise specified the CONTHOS gas analyzer is neither ex-proof nor intrinsically safe in terms of explosion protection.
  • The CONTHOS may not be employed for the analysis of ignitable gas-mixtures. The customer must ensure compliance with applicable regulations when using the analyzer with inflammable or toxic gases or when installing within explosion endangered environments.
  • The customer must ensure that the sample gas is dry and free of particulates.

Process Gas Analysis

19“ & field housing thermal conductivity hydrogen process gas analyzer – CONTHOS 3 - TCD

CONTHOS 3-TCD
Thermal Conductivity Hydrogen Gas Analyzer

Typical Applications

  • Metallurgical process gases - blast furnace
  • Steel - heat treatment & hardening
  • Petrochemistry - synthesis & reformer gas
  • Gas purity - PSA, LEL/UEL & inert gas
  • H2 & O2 purity – water electrolysis

Key Features

  • (Quasi)-binary H2 & noble gas analysis
  • 0 - 0.5% & 99.5 - 100% H2
  • Fast T90 ≤ 3 sec
  • Corrosion resistant TCD
details button
ATEX field housing thermal conductivity H2 process gas analyzer - CONTHOS 3 – TCD Ex p

CONTHOS 3-TCD Ex p | ATEX
Thermal Conductivity Hydrogen Gas Analyzer

Typical Applications

  • Metallurgical - blast furnace, steel
  • Heat treatment & hardening
  • Synthesis & reformer gas
  • Coal, wood & biogas gasification
  • UEL/LEL & H2 in turbogenerators
  • H2 & O2 purity - water electrolysis

Key Features

  • Hydrogen in hazardous areas
  • Binary flammable gases
  • Fast T90 ≤ 3 sec
  • HT corrosion resistant TCD
  • ATEX Ex p zone 1 & 2
details button
High-temperature thermal conductivity H2 process gas analyzer - CONTHOS 3 – TCD HT

CONTHOS 3-TCD HT
High Temperature
Thermal Conductivity Hydrogen Gas Analyzer

Typical Applications

  • Metallurgy – nitration & nitrocarburizing
  • Process gas with Cl2, HCl & H2O
  • H2 with acidic and alkaline components - NH3 & CO2
  • Processes with H2, water vapor and high dew points

Key Features

  • Entire gas path up to 180°C
  • Corrosion resistant HT TCD
  • High sample gas dew points
  • Avoidance of potential salification
details button
19“ & field housing paramagnetic oxygen process gas analyzer – CONTHOS 3 - PMD

CONTHOS 3-PMD
Paramagnetic Oxygen Gas Analyzer

Typical Applications

  • Fast process gas T90 ≤ 5 sec
  • Flue gas control
  • Inertization plants
  • Biogas O2 measurement
  • Air separation, O2 gas purity
  • Metallurgical, chemistry, petrochemistry

Key Features

  • Paramagnetic specific O2 analysis
  • Magnetomechanical "dumbbell" principle
  • T controlled high stability sensor
  • Cells for corrosive gases & solvents
  • Intrinsically safe PMA cell
details button
Field housing backpressure controller for process gas analyzers - pControl 2F

pControl 2F | Backpressure Controller
for process gas analysis instrumentation

Typical Applications

  • Precise measurement at constant pressure instead of insufficient or impossible pressure correction algorithms
  • Long-term stable pressure control also for gases with high corrosion potential
  • Sample gas return into process at defined higher pressure
  • Defined setpoint pressure to dispose of flammable and toxic sample gases into a flare or scrubber

Key Features

  • Eliminate pressure errors at the source
  • Quick and precise pressure control
  • Back pressure regulator for sample conditioning systems
  • Extremely wide range of gas flow allows use with multiple gas analyzers
details button

CONTHOS 3 - TCD HT
High Temperature Thermal Conductivity Hydrogen Gas Analyzer

Features and typical applications
Description
Model variations
Technical data
Downloads

High temperature thermal conductivity Hydrogen process gas analyzer - CONTHOS 3 – TCD HT

Typical Applications

  • Metallurgical process gases such as nitration and nitrocarburizing
  • Heat treatment & hardening with hydrogen, ammonia and carbon dioxide
  • Chemical processes with hydrogen as well as acidic and alkaline components
  • Monitoring of processes with hydrogen, water vapor and high dew points

Key Features

  • High temperature analyzer with thermostat controlled gas paths up to 180°C for high dew points
  • High temperature analyzer up to 180°C to avoid possible salification
  • Extremely long term stable analysis of H2 in binary and quasi-binary gas mixtures
  • Ultra-fast response T90 ≤ 3 sec
  • Highly corrosion resistant TCD cell with Al2O3, glass and quartz for process gases with Cl2, HCl, H2O or NH3, CO2, H2O and H2

Description

The CONTHOS 3 TCD HT is a high temperature thermal conductivity gas analyzer specially developed by LFE for on-line monitoring based on extractive methods for hot and wet gas analysis in process industry applications.

The special outstanding technical features of LFE's high temperature gas analyzer are:

 

  • High temperature resistance and thermostat control of all gas paths being in contact with the sample gas - thermostat control from 70°C to max. 180°C
  • High temperature version of thermal conductivity detector - thermostat controlled temperature from 70°C to max. 180°C
  • Control of the heated gas paths in the analyzer including alarm signals for the safe compliance with a minimum temperature for hot gas analysis
  • High corrosion resistance in the entire sample gas path
  • Extraordinarly high long-term stability
  • Intuitive user-interface based on NAMUR recommendations
  • Optional dynamic interference correction of up to 3 gases in conjunction with external, selective gas analyzer channels

The technical features of the CONTHOS 3 TCD HT gas analyzer open up new areas of application for the thermal conductivity principle for measurement of hot and wet sample gases where “cold” extractive analysis methods cannot be considered.

High temperature thermal conductivity Hydrogen process gas analyzer - CONTHOS 3 – TCD HT

The high temperature version includes the complete thermostat control of the TCD detector as well as all gas paths and connectors within the analyzer for temperatures above the sample gas dew-point in conjunction with external heated gas lines for gas inlet and gas outlet.

 

The LFE CONTHOS 3 TCD HT gas analyzer has proven itself in many years of continuous operation of hot extractive gas analysis in fields such as:

 

  • in corrosive process gases in the chemical and petrochemical industry
  • in thermostat controlled applications with high dew-points
  • in thermostat controlled applications avoiding the formation of salts through acidic and alkaline sample gas components

 

LFE's Thermal Conductivity Detector (TCD)

In conventional gas analyzers utilizing the principle of thermal conductivity a heated object is suspended in a volume containing the sample gas. Electrical energy passed through the object results in the object heating up and attaining an equilibrium temperature which is primarily dependent upon the thermal conduction properties of the surrounding gas. This temperature is normally measured directly as a change in the electrical resistance of the heated object itself.

LFE´s unique principle modifies this "classical" method by spatially and electrically decoupling the heated element from the temperature sensing element. The specially designed geometry of the TCD cell in conjunction with the decoupling effectively suppresses undesired competing thermal effects (i.e. free and forced convectional effects). The result is an instrument whose quick, stable response requires no compromise between gas flow and response time.

Features

  • micro-miniaturized for quick response behavior
  • corrosion and temperature resistant
  • made of aluminum oxide (Al2O3), glass and SiOx-coated platinum sensor filaments

Corrosion and temperature resistant thermal conductivity detector – fast response TCD

Model variations

CONTHOS 3E - TCD
19" rack housing for cabinet mounting – absolute and suppressed TCD ranges with interference correction
19" rack housing
(protective class IP40)
CONTHOS 3F - TCD
IP65 field housing - absolute and suppressed thermal conductivity ranges for multi-component gas mixtures
Field housing
(protective class IP65)
CONTHOS 3F - TCD Ex p
Explosion protected ATEX field housing - absolute and suppressed TCD ranges for multi-component mixtures
Explosion protected
ATEX version for ex zone 1 & 2
CONTHOS 3F-TCD HT
CONTHOS 3F TCD HT - High temperature thermal conductivity gas analyzer
High temperature
version

Options

  • Up to 3 switchable ranges: independently configurable, suppressed & absolute (non-suppressed)
  • Dynamic interference correction of accompanying components in multi-component gas mixtures in conjunction with external, selective gas analyzers
  • Digital I/O board for remote range switching, range identification, threshold contacts, etc.
  • RS-485 interface with Modbus RTU protocol
  • TC detector with flowing reference cell (CONTHOS 3E & 3F)

Technical Data

 CONTHOS 3E
19”-rack housing
CONTHOS 3F
field housing

CONTHOS 3F - Ex p
ATEX compliant Ex p system

CONTHOS 3F - HT
high temperature version

Technical specifications subject to change without notice

  19" rack housing thermal conductivity detector to analyze 0 – 0.5% H2 and 99.5 – 100% hydrogen Purgeable wall mounting housing thermal conductivity detector to analyze 0 – 0.5% H2 and 99.5 – 100% hydrogen ATEX compliant ex zone 1 & 2 Ex p housing for hydrogen measurement - CONTHOS 3 – TCD Ex p High temperature hydrogen measurement - CONTHOS 3 – TCD HT
 

for mounting in 19" cabinet

purgeable steel housing for wall mounting; with separate compartments for the electronic components and the analytical components

Enclosure & electrical data

Dimensions
(H x W x D)

133 x 483 x 427 mm
(3U / 84HP)

434 x 460 x 270 mm

490 x 460 x 270 mm

502 x 460 x 270 mm

Protection class

IP40

IP65

Electrical hazardous area class

   

Protection type "px" for zones 1 & 2 according to EN 60079

Ex protective class of system: II 2 G, Ex p II T4

 

Weight

approx. 10 kg

approx. 25 kg

approx. 30 kg

approx. 25 kg

Power requirements

100-240 VAC (48-62Hz; nominal voltage range: 88-253 VAC; 100 VA max. during warm-up period)

 

Common Technical Data
CONTHOS 3E | CONTHOS 3F | CONTHOS 3F - Ex p | CONTHOS 3F - HT

Technical specifications subject to change without notice

Measuring characteristics

Measuring principle

Thermal conductivity (TCD). Difference in thermal conductivity (Δλ) of various gases

Measuring ranges

Up to 3 linearized, independently configurable, switchable ranges.
Suppressed output ranges within the corresponding reference range can be easily configured.
Range switching is accomplished manually, automatically and/or remotely via optional digital inputs.

lowest range: 0 - 0.5% H2 in N2 or 99.5-100% H2 in N2 (or equivalent Δλ)
largest range: 0 - 100% H2

Calibration

Manual: 2-point (zero / span) calibration
Option: automatic or remote calibration in conjunction with the optional digital I/O-board or RS-485

Warm-up time

dependent upon TCD operating temperature as well as the ambient temperature:
70°C: approx. 20 min.; 180°C: approx. 90 min.

Response time t90

≤ 3 sec (at 60 l/h gas flow and minimum signal dampening level)

Influence of gas flow

between 3 - 30 l/h: < 0.5% of range span for a gas flow change of ±10 l/h
between 30 - 60 l/h: < 1% of range span for a gas flow change of ±10 l/h

Higher flow rates up to e.g. 120 l/h are possible. At these higher flow rates it is recommended that the analyzer be calibrated at the operating flow rate.

Pressure influence

The TCD principle has a normally negligible pressure dependency. At very low ranges it can be seen as a proportional signal offset.

Gas specific order of magnitude: < 0.02% H2 equivalent per 100 mbar

Detection limit 1

≤ 0.5% of span (at signal dampening level: 1 sec)

Linearity/ Accuracy 1

≤ 0.5% of span

Reproducibility 1

≤ 0.5% of span

Response drift 1

Zero: ≤ 1% of span per week
Span: ≤ 1% of span per week

Ambient temperature influence

Zero: ≤ 1% of span per 10 K
Span: ≤ 1% of span per 10 K

Ambient temperature in operation

allowed temperature range : +5 to +45°C

Influence of inclination

no influence

 CONTHOS 3E
19”-rack housing
CONTHOS 3F
field housing

CONTHOS 3F - Ex p
ATEX compliant Ex p system

CONTHOS 3F - HT
high temperature version

Technical specifications subject to change without notice

  19" rack housing thermal conductivity detector to analyze 0 – 0.5% H2 and 99.5 – 100% hydrogen Purgeable wall mounting housing thermal conductivity detector to analyze 0 – 0.5% H2 and 99.5 – 100% hydrogen ATEX compliant ex zone 1 & 2 Ex p housing for hydrogen measurement - CONTHOS 3 – TCD Ex p High temperature hydrogen measurement - CONTHOS 3 – TCD HT

Materials in contact with sample gas

TC Detector

Al2O3-ceramic and sapphire, glass and SiOx-coated Pt measuring filaments
high corrosion and temperature resistance

Internal gas lines

standard: PTFE / PFA

optional: stainless steel tubing
(SS 321; similar to 1.4541) and 1.4571

standard: PTFE / PFA

optional: stainless steel tubing
(SS 321; similar to 1.4541)

stainless steel tubing
(SS 321; similar to 1.4541)

Sample gas connectors

Standard: stainless steel (SS 316; similar to 1.4401)
Standard: Swagelok® connectors for ø6mm tubing

Optional: Swagelok® connectors for ø¼" tubing

Optional: NPT ¼" (female)

Optional: Swagelok® connectors for ø¼" tubing

 

Optional: Swagelok® connectors for ø¼" tubing

Optional : PFA connectors for synthetic tubing DN 4/6
(only in conjunction with PTFE tubing)

 
 

Common Technical Data
CONTHOS 3E | CONTHOS 3F | CONTHOS 3F - Ex p | CONTHOS 3F - HT

Technical specifications subject to change without notice

Data display, inputs and outputs

User Interface

LC-display (40 characters x 16 lines) + bar graph

Plain text description of instrument status as well as digital status output

Language: switchable between English & German

Analog signal output

2 independently configurable, galvanically isolated analog outputs (with common ground; RLoad = 600 Ohm max)

Available output levels: 0 - 20 mA, 4 - 20 mA, 4 - 20 mA with superimposed instrument status (NAMUR NE 43 compliant) as well as test signal levels (0, 4, 10, 12 & 20 mA)

Digital outputs
1 to 3
(instrument status)

Instrument status (NAMUR NE 107 compliant) via floating contacts (28 V max.; 350 mA max.)

FAILURE (DO 1) | MAINTENANCE REQUIRED (DO 2) | FUNCTION CHECK (DO 3)

Analog inputs
(optional)

3 galvanically isolated, configurable analog inputs for interference correction
0 - 20 mA or 4 - 20 mA (Ri = 50 Ohm)

Interference correction

3 correction channels for static and/or dynamic interference correction (dynamic correction only in conjunction with the optional analog inputs or RS-485)

Digital I/O
(optional)

Digital inputs: 8 configurable, optically isolated inputs (6 - 24 VDC; 10 mA max.)

  • remote range selection
  • remote triggering of zero and span calibration
  • remote triggering and cancelling of automatic calibration
  • switching of interference correction analog inputs to a secondary input range
  • mapping of user defined input to a digital output

Digital outputs: 7 configurable, floating relay contacts (28 V max.; 350 mA max.)

  • threshold monitoring (1 threshold per measuring range)
  • feedback as to the current range
  • calibration gas selection
  • mapping of user defined input to a digital output

(Note: The digital I/O board cannot be used in conjunction with the RS-485 serial interface hardware.)

RS-485
(optional)

with Modbus communications protocol; galvanically isolated interface
(Note: The RS-485 serial interface hardware cannot be used in conjunction with the digital I/O board.)

Service interface

non-isolated serial interface for accessing the instrument's configuration via a proprietary PC software

1 at constant temperature and pressure

 

  • The stability data is valid for analyzer operation with pure bottled gases. Instrument accuracy is based on binary or quasi-binary gas mixtures. Deviations from the above data can occur in conjunction with process gases depending upon the gas quality and the degree of gas handling.
  • Unless otherwise specified the CONTHOS gas analyzer is neither ex-proof nor intrinsically safe in terms of explosion protection.
  • The CONTHOS may not be employed for the analysis of ignitable gas-mixtures. The customer must ensure compliance with applicable regulations when using the analyzer with inflammable or toxic gases or when installing within explosion endangered environments.
  • The customer must ensure that the sample gas is dry and free of particulates.

pControl 2F
Backpressure Controller for process gas analyzers

Features and typical applications
Description
Technical data
Downloads

Corrosion resistant backpressure controller for process gas analyzers - pControl 2F

Typical Applications

  • Precise measurement at constant pressure instead of insufficient or impossible pressure correction algorithms
  • Long-term stable pressure control also for gases with high corrosion potential
  • Sample gas return into process at defined higher pressure
  • Defined setpoint pressure to dispose of flammable and toxic sample gases into a flare or scrubber

Key Features

  • Eliminate pressure errors at the source
  • Quick and precise pressure control
  • Back pressure regulator for sample conditioning systems
  • Extremely wide range of gas flow allows use with multiple gas analyzers

Description

In the field of gas analysis an analyzer's response is often dependent upon the sample gas pressure. Pressure dependency can occur through a number of different physical parameters simultaneously and can be difficult to impossible to correct for. The best and most accurate approach is therefore to control the absolute pressure itself. The use of an LFE pControl backpressure controller alleviates the need for complicated correction algorithms.

A further benefit of an LFE pControl backpressure controller is e.g. the return of the analyzed gases back into the process (being achieved by a defined higher pressure). Alternatively the sample gas can be fed to a flare or scrubber requiring a defined higher pressure. In this way unnecessary emissions into the environment or loss of gas can be avoided. Flammable or toxic gases can be handled appropriately. The LFE pControl backpressure controller typically operates at approximately 0.2 bars above ambient pressure (i.e. 1.2 bar absolute), but can be easily set to other operating pressures.

Backpressure controller instead of pressure corrections with wide flow range for gas analyzers - pControl 2F

The specially designed control valve of the LFE backpressure controller provides for an extremely constant pressure over an extremely wide range of gas flow (e.g. from 5 ln/h up to 1000 ln/h). This allows for a single LFE pControl to be used in conjunction with a number of gas analyzers.

The piezo-resistive pressure transducer is temperature controlled to improve stability. An optional PTFE isolating diaphragm is available to improve corrosion resistance.

 

Features

  • Eliminate pressure errors at the source instead of calculated corrections
  • Adjustable, quick and precise pressure control
  • Extremely wide range of gas flow: 5 up to 1000 ln/h
  • A single pControl system for use with multiple gas analyzers
  • High corrosion resistant version for aggressive gases
  • Improved stability by temperature controlled transducer
  • Sample gas return into process instead of emissions
  • Flammable and toxic gases via flare or scrubber

Technical data

Technical specifications subject to change without notice

Enclosure & electrical data

Enclosure Purgeable cast aluminum housing for wall-mounting
Protection class IP65
Dimensions 230 x 330 x 185 mm (HxWxD)
Weight approx. 10 kg
Power supply 100 - 240 VAC / 50 - 60 Hz / 50 VA max.
Materials in contact with sample gas
Internal gas lines PTFE and PVDF
Control valve PTFE and PVDF with FPM seals
Sample gas connectors Standard: stainless steel (SS 316)
Option: PVDF (in conjunction with optional PTFE isolating membrane)
Pressure transducer Polyester, silicon and silicone compounds
Note: enhanced corrosion resistance is attained with the optional PTFE isolating membrane

Operational characteristics

Measuring range Standard: 1.0 - 1.5 bar absolute (other ranges on request)
Range of flow Dependent upon setpoint pressure and pressure at gas outlet.
Example: setpoint at 1.2 bar (abs.) and outlet at atmospheric pressure:
Range of flow: 5 - 1000 ln/h
 Resolution  < 0.3% of range span
 Reproducibility  better than ± 0.3% of range span

Data display, inputs and outputs

User Interface LC display (40 characters x 16 lines) + bar graph
Plaintext description of instrument status as well as digital status output
Language: switchable between English & German
Instrument Status Plaintext description on the LC display as well as categorization into one of the following states
(NAMUR NE 107 compliant): FAILURE | MAINTENANCE REQUIRED | FUNCTION CHECK
Analog signal output Galvanically isolated analog output
Available output levels:
• 0-20 mA or 4-20 mA
• 0-20 mA limited (current limited from 0 to 20.5 mA)
• 4-20 mA limited (current limited from 3.8 to 20.5 mA)
• 4-20 mA with superimposed instrument status (NAMUR NE 43 compliant)
• Test signal levels: 0 mA, 4 mA, 10 mA, 12 mA & 20 mA
Digital outputs 3 configurable, floating contacts for instrument status and/or
threshold monitoring
Default configuration: Instrument status (NAMUR NE 107 compliant):
FAILURE  |  MAINTENANCE REQUIRED  |  FUNCTION CHECK
Analog input (optional) 0(4) - 20 mA input (galv. isolated) for optional external setpoint control

 

Downloads  EN

pControl 2F | Backpressure Controller

Brochures

      pdf LFE Product Overview

 

Product Data Sheets

      pdf pControl 2F | Backpressure Controller

Technical specifications subject to change without notice

CONTHOS 3 - TCD Ex p
ATEX Thermal Conductivity Hydrogen Gas Analyzer

Features and typical applications
Description
Model variations
Technical data
Downloads

ATEX field housing thermal conductivity Hydrogen process gas analyzer - CONTHOS 3 – TCD Ex p

Typical Applications

  • Metallurgical process gases such as blast furnace with flammable gases in hazardous areas
  • Steel industry: Heat treatment & hardening
  • Petrochemistry: Flammable gases in hazardous areas - Gas processing to synthesis/ reformer gas & coal gasification
  • Monitoring of gas purity, pressure swing adsorption and LEL/UEL
  • H2 and O2 purity in water electrolysis
  • Monitoring of hydrogen in turbogenerators

Key Features

  • Extremely long term stable analysis of H2 and noble gases in binary and quasi-binary gas mixtures with lowest and extreme suppressed ranges: 99.5 -100%
  • Ultra-fast response  T90 ≤ 3 sec
  • Highly corrosion and temperature resistant TCD detector with Al2O3, glass and quartz
  • ATEX Ex p version for ex zones 1 and 2
  • Extremely low purge gas consumption

Description

The CONTHOS 3 - TCD Ex p state-of-the-art thermal conductivity gas analyzer is an analytical instrument developed for online industrial use in hazardous areas.

The special outstanding technical features of LFE's microprocessor controlled gas analyzer are:

 

  • High temperature version of thermal conductivity detector - thermostat controlled temperature from 50°C to max. 120°C
  • High corrosion resistance in the entire sample gas path
  • Low detection limit in the lower ppm range
  • Response highly independent of the gas flow
  • Extraordinarily high long-term stability
  • Intuitive user-interface based on NAMUR recommendations
  • Automatic self-diagnosis
  • Optional dynamic interference correction of up to 3 gases in conjunction with external, selective gas analyzer channels

The technical features of the unique CONTHOS 3 - TCD Ex p gas analyzer open up new areas of application for the thermal conductivity principle in hazardous areas also including the measuring of flammable gases.

The selected thermostat temperature of the detector can help minimize the cross interference of possible accompanying gas components. Furthermore, accompanying gases can be measured by means of suitable external measuring methods and an interference correction of these components can be carried out.

ATEX high temperature, corrosion resistant TCD analyzer - H2 process gas analyzer - CONTHOS 3 – TCD Ex p

 

First developed in 1979 the LFE CONTHOS gas analyzer has proven itself in many years of continuous operation. The CONTHOS 3 - TCD ­Ex p is used in ex zone 1 and 2 fields such as:

 

  • in corrosive process gases in the chemical and petrochemical industry
  • in thermostat controlled applications up to 120°C
  • in all of the "classical" applications of the TCD principle with outstanding measurement performance

 

LFE's Thermal Conductivity Detector (TCD)

In conventional gas analyzers utilizing the principle of thermal conductivity a heated object is suspended in a volume containing the sample gas. Electrical energy passed through the object results in the object heating up and attaining an equilibrium temperature which is primarily dependent upon the thermal conduction properties of the surrounding gas. This temperature is normally measured directly as a change in the electrical resistance of the heated object itself.

LFE´s unique principle modifies this "classical" method by spatially and electrically decoupling the heated element from the temperature sensing element. The specially designed geometry of the TCD cell in conjunction with the decoupling effectively suppresses undesired competing thermal effects (i.e. free and forced convectional effects). The result is an instrument whose quick, stable response requires no compromise between gas flow and response time.

Features

  • micro-miniaturized for quick response behavior
  • corrosion and temperature resistant
  • made of aluminum oxide (Al2O3), glass and SiOx-coated platinum sensor filaments

Corrosion and temperature resistant thermal conductivity detector – fast response TCD

Model variations

CONTHOS 3E - TCD
19" rack housing for cabinet mounting – absolute and suppressed TCD ranges with interference correction
19" rack housing
(protective class IP40)
CONTHOS 3F - TCD
IP65 field housing - absolute and suppressed thermal conductivity ranges for multi-component gas mixtures
Field housing
(protective class IP65)
CONTHOS 3F - TCD Ex p
Explosion protected ATEX field housing - absolute and suppressed TCD ranges for multi-component mixtures
Explosion protected
ATEX version for ex zone 1 & 2
CONTHOS 3F-TCD HT
CONTHOS 3F TCD HT - High temperature thermal conductivity gas analyzer
High temperature
version

Options

  • Up to 3 switchable ranges: independently configurable, suppressed & absolute (non-suppressed)
  • Dynamic interference correction of accompanying components in multi-component gas mixtures in conjunction with external, selective gas analyzers
  • Digital I/O board for remote range switching, range identification, threshold contacts, etc.
  • RS-485 interface with Modbus RTU protocol
  • TC detector with flowing reference cell (CONTHOS 3E & 3F)

Technical Data

 CONTHOS 3E
19”-rack housing
CONTHOS 3F
field housing

CONTHOS 3F - Ex p
ATEX compliant Ex p system

CONTHOS 3F - HT
high temperature version

Technical specifications subject to change without notice

  19" rack housing thermal conductivity detector to analyze 0 – 0.5% H2 and 99.5 – 100% hydrogen Purgeable wall mounting housing thermal conductivity detector to analyze 0 – 0.5% H2 and 99.5 – 100% hydrogen ATEX compliant ex zone 1 & 2 Ex p housing for hydrogen measurement - CONTHOS 3 – TCD Ex p High temperature hydrogen measurement - CONTHOS 3 – TCD HT
 

for mounting in 19" cabinet

purgeable steel housing for wall mounting; with separate compartments for the electronic components and the analytical components

Enclosure & electrical data

Dimensions
(H x W x D)

133 x 483 x 427 mm
(3U / 84HP)

434 x 460 x 270 mm

490 x 460 x 270 mm

502 x 460 x 270 mm

Protection class

IP40

IP65

Electrical hazardous area class

   

Protection type "px" for zones 1 & 2 according to EN 60079

Ex protective class of system: II 2 G, Ex p II T4

 

Weight

approx. 10 kg

approx. 25 kg

approx. 30 kg

approx. 25 kg

Power requirements

100-240 VAC (48-62Hz; nominal voltage range: 88-253 VAC; 100 VA max. during warm-up period)

 

Common Technical Data
CONTHOS 3E | CONTHOS 3F | CONTHOS 3F - Ex p | CONTHOS 3F - HT

Technical specifications subject to change without notice

Measuring characteristics

Measuring principle

Thermal conductivity (TCD). Difference in thermal conductivity (Δλ) of various gases

Measuring ranges

Up to 3 linearized, independently configurable, switchable ranges.
Suppressed output ranges within the corresponding reference range can be easily configured.
Range switching is accomplished manually, automatically and/or remotely via optional digital inputs.

lowest range: 0 - 0.5% H2 in N2 or 99.5-100% H2 in N2 (or equivalent Δλ)
largest range: 0 - 100% H2

Calibration

Manual: 2-point (zero / span) calibration
Option: automatic or remote calibration in conjunction with the optional digital I/O-board or RS-485

Warm-up time

dependent upon TCD operating temperature as well as the ambient temperature:
70°C: approx. 20 min.; 180°C: approx. 90 min.

Response time t90

≤ 3 sec (at 60 l/h gas flow and minimum signal dampening level)

Influence of gas flow

between 3 - 30 l/h: < 0.5% of range span for a gas flow change of ±10 l/h
between 30 - 60 l/h: < 1% of range span for a gas flow change of ±10 l/h

Higher flow rates up to e.g. 120 l/h are possible. At these higher flow rates it is recommended that the analyzer be calibrated at the operating flow rate.

Pressure influence

The TCD principle has a normally negligible pressure dependency. At very low ranges it can be seen as a proportional signal offset.

Gas specific order of magnitude: < 0.02% H2 equivalent per 100 mbar

Detection limit 1

≤ 0.5% of span (at signal dampening level: 1 sec)

Linearity/ Accuracy 1

≤ 0.5% of span

Reproducibility 1

≤ 0.5% of span

Response drift 1

Zero: ≤ 1% of span per week
Span: ≤ 1% of span per week

Ambient temperature influence

Zero: ≤ 1% of span per 10 K
Span: ≤ 1% of span per 10 K

Ambient temperature in operation

allowed temperature range : +5 to +45°C

Influence of inclination

no influence

 CONTHOS 3E
19”-rack housing
CONTHOS 3F
field housing

CONTHOS 3F - Ex p
ATEX compliant Ex p system

CONTHOS 3F - HT
high temperature version

Technical specifications subject to change without notice

  19" rack housing thermal conductivity detector to analyze 0 – 0.5% H2 and 99.5 – 100% hydrogen Purgeable wall mounting housing thermal conductivity detector to analyze 0 – 0.5% H2 and 99.5 – 100% hydrogen ATEX compliant ex zone 1 & 2 Ex p housing for hydrogen measurement - CONTHOS 3 – TCD Ex p High temperature hydrogen measurement - CONTHOS 3 – TCD HT

Materials in contact with sample gas

TC Detector

Al2O3-ceramic and sapphire, glass and SiOx-coated Pt measuring filaments
high corrosion and temperature resistance

Internal gas lines

standard: PTFE / PFA

optional: stainless steel tubing
(SS 321; similar to 1.4541) and 1.4571

standard: PTFE / PFA

optional: stainless steel tubing
(SS 321; similar to 1.4541)

stainless steel tubing
(SS 321; similar to 1.4541)

Sample gas connectors

Standard: stainless steel (SS 316; similar to 1.4401)
Standard: Swagelok® connectors for ø6mm tubing

Optional: Swagelok® connectors for ø¼" tubing

Optional: NPT ¼" (female)

Optional: Swagelok® connectors for ø¼" tubing

 

Optional: Swagelok® connectors for ø¼" tubing

Optional : PFA connectors for synthetic tubing DN 4/6
(only in conjunction with PTFE tubing)

 
 

Common Technical Data
CONTHOS 3E | CONTHOS 3F | CONTHOS 3F - Ex p | CONTHOS 3F - HT

Technical specifications subject to change without notice

Data display, inputs and outputs

User Interface

LC-display (40 characters x 16 lines) + bar graph

Plain text description of instrument status as well as digital status output

Language: switchable between English & German

Analog signal output

2 independently configurable, galvanically isolated analog outputs (with common ground; RLoad = 600 Ohm max)

Available output levels: 0 - 20 mA, 4 - 20 mA, 4 - 20 mA with superimposed instrument status (NAMUR NE 43 compliant) as well as test signal levels (0, 4, 10, 12 & 20 mA)

Digital outputs
1 to 3
(instrument status)

Instrument status (NAMUR NE 107 compliant) via floating contacts (28 V max.; 350 mA max.)

FAILURE (DO 1) | MAINTENANCE REQUIRED (DO 2) | FUNCTION CHECK (DO 3)

Analog inputs
(optional)

3 galvanically isolated, configurable analog inputs for interference correction
0 - 20 mA or 4 - 20 mA (Ri = 50 Ohm)

Interference correction

3 correction channels for static and/or dynamic interference correction (dynamic correction only in conjunction with the optional analog inputs or RS-485)

Digital I/O
(optional)

Digital inputs: 8 configurable, optically isolated inputs (6 - 24 VDC; 10 mA max.)

  • remote range selection
  • remote triggering of zero and span calibration
  • remote triggering and cancelling of automatic calibration
  • switching of interference correction analog inputs to a secondary input range
  • mapping of user defined input to a digital output

Digital outputs: 7 configurable, floating relay contacts (28 V max.; 350 mA max.)

  • threshold monitoring (1 threshold per measuring range)
  • feedback as to the current range
  • calibration gas selection
  • mapping of user defined input to a digital output

(Note: The digital I/O board cannot be used in conjunction with the RS-485 serial interface hardware.)

RS-485
(optional)

with Modbus communications protocol; galvanically isolated interface
(Note: The RS-485 serial interface hardware cannot be used in conjunction with the digital I/O board.)

Service interface

non-isolated serial interface for accessing the instrument's configuration via a proprietary PC software

1 at constant temperature and pressure

 

  • The stability data is valid for analyzer operation with pure bottled gases. Instrument accuracy is based on binary or quasi-binary gas mixtures. Deviations from the above data can occur in conjunction with process gases depending upon the gas quality and the degree of gas handling.
  • Unless otherwise specified the CONTHOS gas analyzer is neither ex-proof nor intrinsically safe in terms of explosion protection.
  • The CONTHOS may not be employed for the analysis of ignitable gas-mixtures. The customer must ensure compliance with applicable regulations when using the analyzer with inflammable or toxic gases or when installing within explosion endangered environments.
  • The customer must ensure that the sample gas is dry and free of particulates.

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