LFE - CONTHOS 3 - TCD Ex d | IECEx/ATEX Thermal Conductivity Hydrogen Gas Analyzer

Features and typical applications

IECEx / ATEX field housing thermal conductivity Hydrogen process gas analyzer - CONTHOS 3 – TCD Ex d

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
Corrosion- and temperature resistant TCD detector with Al₂O₃, glass and quartz
IECEx / ATEX Ex d version for ex zones 1 and 2

Typical Applications

H₂ and O₂ purity in water electrolysis
Monitoring of hydrogen in turbogenerators
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

Description

The CONTHOS 3 - TCD Ex d - Transmitter state-of-the-art thermal conductivity gas analyzer is an analytical instrument developed for online industrial use in hazardous areas. The Ex d version is designed for measurement applications in industrial processes located in Ex Zones 1 and 2.

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

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 d - Transmitter 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 d Transmitter 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 SiO_x-coated platinum sensor filaments

CONTHOS TCD model variations

Technical data

Technical Data

Enclosure & Electrical Data

	CONTHOS 3E 19”-rack housing	CONTHOS 3F field housing	CONTHOS 3 - Ex d IECEx/ATEX compliant Exd Transmitter	CONTHOS 3F - Ex p ATEX compliant Exp system	CONTHOS 3F - HT high temperature version
Technical specifications subject to change without notice

	for mounting in 19" cabinet	purgeable steel housing for wall mounting; with separate compartments for the electronic components and the analytical components	wall-mounted Ex d enclosure made of light metal flameproof enclosure (CONTHOS 3E or 3F control unit located in safe area required)	purgeable steel housing for wall mounting; with separate compartments for the electronic components and the analytical components	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	434 x 460 x 270 mm	433 x 410 x 281 mm	490 x 460 x 270 mm	502 x 460 x 270 mm
Protection class	IP40	IP65	IP66	IP65	IP65
Electrical hazardous area class			TCD transmitter* Ex II 2 G Ex db IIC T5 Gb (suitable for zones 1 & 2) (*CONTHOS 3E or 3F control unit located in safe area required)	Ex protective class of system: II 2 G, Ex p II T4 according to EN 60079 (suitable for zones 1 & 2)
Weight	approx. 10 kg	approx. 25 kg	approx. 35 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)				100-240 VAC (48-62Hz; nominal voltage range: 88-253 VAC; 130 VA max. during warm-up period)

Measuring Characteristics

Common Technical Data CONTHOS 3E \| CONTHOS 3F \| CONTHOS 3-Transmitter - Ex d \| 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 Modbus interface (RS-485 or TCP)
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

Materials

	CONTHOS 3E 19”-rack housing	CONTHOS 3F field housing	CONTHOS 3 - Ex d IECEx/ATEX compliant Exd Transmitter	CONTHOS 3F - Ex p ATEX compliant Exp system	CONTHOS 3F - HT high temperature version
Technical specifications subject to change without notice

Materials in contact with sample gas
TC Detector	Al₂O₃-ceramic and sapphire, glass and SiO_x-coated Pt measuring filaments high corrosion and temperature resistance
Internal gas lines	Standard: PTFE / PFA Optional: stainless steel tubing		Stainless steel tubing
Sample gas connectors	Standard: Swagelok^® connectors stainless steel (SS 316; similar to 1.4401) for ø6mm tubing		o.d. ø1/4" stainless steel tubing	Swagelok^® connectors stainless steel (SS 316; similar to 1.4401) for ø6mm tubing	Standard: Swagelok^® connectors stainless steel (SS 316; similar to 1.4401) for ø6mm tubing
Sample gas connectors	Optional: Swagelok^® connectors for ø¼" tubing Optional: NPT 1/4" (female) Optional : PFA connectors for synthetic tubing DN 4/6 (only in conjunction with PTFE tubing)	Optional: Swagelok^® connectors for ø1/4" tubing			Optional: Swagelok^® connectors for ø1/4" tubing

Instrument Interface

Common Technical Data CONTHOS 3E \| CONTHOS 3F \| CONTHOS 3-Transmitter - Ex d \| 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; R_Load = 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 (R_i = 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 Modbus interface (RS-485 or TCP)
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
Modbus interface (optional)	Modbus RTU - RS485 Modbus TCP
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.

CONTHOS 3 - TCD Transmitter Ex d

Features and typical applications

Key Features

Typical Applications

Description

Description

LFE's Thermal Conductivity Detector (TCD)

Features

CONTHOS TCD model variations

Model variations

Common Options

Technical data

Technical Data

Enclosure & Electrical Data

Measuring Characteristics

Materials

Instrument Interface

Downloads

Downloads

CONTHOS 3-TCD | Process Thermal Conductivity Gas Analyzer Series

Brochures and Product Data Sheets

Application Questionnaire

Sample Applications