TCD Gas Chromatograph

TCD Gas Chromatograph - Orthodyne
TCD Gas Chromatograph 600- Orthodyne

TCD Gas Chromatograph

Analysis of H2, O2, Ar, N2, CH4, CO, CO2, Kr, Ne, Xe, He in % level.

Pattern of Approval Russia | Pattern of Approval China (all certificates)


The TCD Gas Chromatograph is not as sensitive as other detectors but it is non-specific and non-destructive. A TCD detector consists of an electrically-heated wire or thermistor (tungstenrhenium wire). The temperature of the sensing element depends on the thermal conductivity of the gas flowing around it.


Changes in thermal conductivity, such as when organic molecules displace some of the carrier gas, cause a temperature rise in the element which is sensed as a change in resistance.

Response in universal and proportional to concentration

Best gases for TCD Gas Chromatograph : H2 or He. Because of highest thermal conductivity (0.170 and 0.141 J/(K.m.s), respectively, to be compared with N2 0.024 J/(K.m.s) for N2).

For Helium and Hydrogen the temperature conductivity lowers when solute is eluted. The sensitivity is inversely proportional to flow rate: the detector is more sensitive at lower flow rates.

Detection limit: < 5 ppm

To increase sensitivity, the temperature of the block should be maintained at lowest temperature that allows all the solutes remain gaseous.

Some Global References

Company Type of analyser Analyser Measurement
Air Products (Scotland) Mixture TCD O2 (ppm % ), CO2 (%)
Air Products (Poland) Mixture TCD O2 (ppm %), CO2 (%), Ar (%), H2O (%)
Air Liquide (France) Mixture TCD O2 (%), N2 (%), He (%), CO2 (%), Balance Ar (%)
Air Liquide (Denmark) / TCD N2 (%) ASSAY

Type of configurations

DID Gas Chromatograph - 500

Process Line

This new line 500 has been designed for stand alone operation. Easy configuration and quick start-up make this new system ideal for process gas analysis.

In addition to its user-friendly interface (touch screen display), the new line 500 has its own chromatographic software that allows the concentration of each impurity to be displayed directly. Moreover, the new line 500 can be remotely controlled through Ethernet or Internet.

DID Gas Chromatograph Line 500 - Orthodyne

DID Gas Chromatograph Line 500 - Brochure

DID Gas Chromatograph - 600

Laboratory Line

The new line 600 has been designed for working with Chromdyne software on a computer. It make this new system ideal for laboratory process gas analysis. Moreover, the new line 600 can be remotely controlled through Ethernet or Internet.

DID Gas Chromatograph Line 600 - Orthodyne

DID Gas Chromatograph Line 600 - Brochure

Dimensions & chromatogram

TCD Gas Chromatograph Dimensions - Orthodyne

(Dimensions can differ regarding the application)

TCD Gas Chromatograph Chromatogram - Orthodyne

Technical specifications

AccuracyDepend of the range used
Drift1 % over 24 hours
Temperature drift1 % per degree
Operating temperature± 20°C without wide variations of temperature
Sampling gasN2, H2, O2, Ar, He, Air, CH4 , CO, CO2
Sample gas connection1/8’’ Swagelok SS
Sample flow rateApproximately 3 to 5 l/h
Sample pressure< 100 mBar
Carrier gasAll gases, except corrosives ones
Carrier gas connection1/8’’ Swagelok SS
Carrier gas pressure7 bar
Carrier gas fl ow rate4 l/h
Recommended qualityminimum 5.5
Power supply220 Vac, 50-60 Hz
Power consumption500 VA
4-20 mA outputEight configurable outputs
depending on the application
RJ-45 connectionComputerised system maintenance
Output relays
(SPST 2 amperes / 250 Vac)
1 Analyser Failure Alarm contact
1 Alarm High contact
1 Alarm High High contact


5 ppm resolution guaranteed
User-friendly interface
Fast response time
Adjustable alarm and oven settings
CE marked
Possibility of auto-calibration programming
Chromdyne software


Discover which analyser(s) you need for your analytical requests. Check the application here !

Measurement capabilities

The range can be adjusted between 1ppm and 100% following your request.

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    TCD Gas Chromatograph Brochure - Orthodyne