Dissolved Gas Extraction Unit (Model DGEU)
The Dissolved Gas Extraction Unit (DGEU) allows continuous concentration measurements of dissolved gases in water and other liquids in real time*. The DGEU extracts gas from a liquid stream through an internal hydrophobic micro-porous membrane (comprised of polypropylene hollow fibers). Internal water and gas pumps and mass flow controllers allow precise control of flow rates and pressures of the liquid in the DGEU and the strip gas which is sent to the gas analyser. By accurately controlling the water flow rate through the membrane, gas pressure on the outside of the membrane, and water pressure on the inside of the membrane, the DGEU is able to generate precise and reproducible results.
Measuring the gas flow rates in and out of the DGEU, allows the gas-phase concentrations (parts per million) to be easily converted into dissolved gas concentrations (nanomolar).
The Unit is controlled via software on selected LGR analysers to provide autonomous measurements in the field. An internal multi-channel data logger records all parameters reported by the DGEU and can also record analog signals from other instruments in a single data file.
*requires use of trace gas analyser (sold separately)
All LGR Analysers now come with a 2 Year Warranty as standard, underlying the quality and robustness of their manufacture and high reliability. Warranties can also be extended to 3 or 4 years at additional cost, at the time of purchase. Please enquire for further details.
Under normal operation and for the vast majority of applications, LGR Off-axis ICOS gas analysers require the minimum of servicing and maintenance.
One of the many benefits of this technology is long-term unattended reliability in the field.
Annual maintenance would normally include an inspection of the internal pump (or external pump if fitted) and the replacement of the pump diaphragm and valve seals if necessary.
This can be carried out by the user themselves or by ET either on site or back in the ET workshop (for a maintenance quote, please contact us).
ET recommends that LGR Analyser users consider the purchase of a field maintenance kit which includes:
- Replacement solid-state hard-drive with LGR operating system and specific system files pre-loaded, for quick and simple swap-out in the field if ever necessary.
- Pump maintenance kit (internal) to include spare pump diaphragm and valve seals.
- Mirror cleaning kit.
Please contact us if you would like to receive a quote for the field maintenance kit.
Additional maintenance will be required for the LGR Liquid Water Isotope Analyser (LWIA) and Auto-injector unit and also the LGR Dissolved Gas Extraction Unit (DGEU).
For these instruments, please refer to the operation manual supplied with these instruments.
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