CONTHOS 2
H₂ gas analyzer based on the TCD measuring principle

Features

• high-temperature TC-detector (TCD), temperature controlled from 50°C to max. 180°C
• high corrosion-resistance of components in contact with medium
• unusually quick response time: typically ≤ 2 sec
• response highly independent of the gas flow
• unusually high long-term response stability
• intuitive user-interface based on NAMUR^[1] -recommendations
• automatic self-diagnosis
• optional dynamic interference correction of up to 3 gases in conjunction with external, selective gas analyzers

The technical features of the unique CONTHOS 2 gas analyzer open up new areas of application for the thermal-conductivity principle, as well as help to eliminate weak points in present analysis problems.

Choosing the TCD-operating-temperature above that of the dew-point of the sample-gas can, in con­junction with external and internal heated gas lines (field housing only), alleviate the need for a sample-gas cooler.

First developed in 1979 the LFE - CONTHOS gas analyzer has proven itself in many years of continuous operation in such fields as:

• in the iron and steel industry
• in corrosive process gases in the chemical industry
• in all of the "classical" applications of the TCD-principle

Model variations and options

• 19"-rack housing (protective class IP40) or field-housing (protective class IP65)
• EExp ATEX-version in conjunction with purge-gas pressure monitor
• 2nd & 3rd switched ranges: independently configurable, suppressed & non-suppressed
• Interference correction in conjunction with external, selective gas analyzers for multiple gas constituents
• Digital I/O-board for external range switching, threshold contacts, etc.
• Heated gas lines within analyzer housing (max. 140°C; field housing only)

Detector Design

In conventional gas analyzers utilizing the principle of thermal conductivity a heatable 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.

The micro-miniaturized TCD-cell (V = 1mm³) is constructed of the highly corrosion-resistant materials aluminum-oxide (Al₂O₃), glass and platinum.

The detector-assembly is mounted in an insulated, temperature regulated aluminum block and can be operated at continuous temperatures up to 180°C.

• The heating filament and temperature sensing filament are spatially and electronically decoupled.

• Miniaturization of measuring elements and cells (quick response)

• Highly corrosion resistant (materials used: aluminum-oxide (Al₂O₃), glass and Pt)

Downloads

The following documents are currently available for download in Adobe^® PDF-format or in Microsoft^® Word format:

Product / Document type	Language		File name	File format	File size
	English	German
CONTHOS 2 - TCD Gas Analyzer
Application questionnaire			20_appq_en.doc		115 KB
Brochure			20_info_en.pdf		156 KB
Reference list			20_reflist_en.pdf		41 KB
General information
Brochure			LFE_info_overview_en.pdf		118 KB