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

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.

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

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 SiO_x-coated platinum sensor filaments

• 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)

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

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.

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 l_n/h up to 1000 l_n/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.

• 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 l_n/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

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

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.

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

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 SiO_x-coated platinum sensor filaments

• 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)