Gas supplied to the chamber is sub-sampled for analysis by the gas analyzer. To control elevated target gas, the solenoid valve is attached to the outlet of a gas tank containing a high concentration of the target gas. When the concentration of the target gas falls below a user-defined threshold, a signal from the gas analyzer causes the A350 Gas Concentration Controller to open and target gas enters the gas stream and a mixing volume and combines with the major gas before entering the chamber. When target gas concentration in the chamber reaches the user-defined threshold, the solenoid valve is closed.

The same principal is used to regulate the target gas at sub-atmospheric levels in that target gas-free mixture is bled into the major gas stream if the target gas is exceeded.

The flow rate of target gas, entering the system can be controlled by a flow monitor and controller upstream of the solenoid valve. The concentration of the target gas can then be regulated slowly, or more rapidly, when it differs from the threshold level.

MCGES – Multichannel Gas Exchange System allows studies of metabolism and physiology of living organisms via measurements of gas exchange. Qubit Systems can provide Gas Exchange Systems customized to your specifications and needs, to study photosynthesis, respiration, transpiration, N2-fixation and other processes.

MCGES-Multichannel Gas Exchange System may be controlled by the C950 Multichannel Gas Exchange Software to measure the flow of gases to the samples, through the sample chambers and to the gas analyzers. The C950 software controls all data acquisition from the sensors and analyzers, graphically displays the data and calculates gas exchange rates as required. Please  Contact QUBIT with your specifications and we will design your gas exchange system.

In a MCGES the reference gas may be supplied to the system from an air pump or from compressed gas tanks or an air compressor. If several gas mixtures are to be used then a gas mixing system is included (G400). Gasses can be humidified and dehumidified using a humidity controller.

In a multichannel system the gas enters the flow controller where it is split between sample channels, the flow in each channel being controlled by needle valves and measured by separate mass flow monitor. Gas Flow Controllers are available for any number of channels in multiples of four (4 (G248), 8 (G245) channels etc).

Gas enters each sample chamber which may or may not be temperature controlled. The structure of the chamber will depend on the organism. At Qubit, we can build chambers to your specifications. The effluent gas from each chamber enters a Gas Switcher (4 channel - G243, 8 channel – G244) that selects one of the channels for analysis, and vents the others to the atmosphere. Alternatively, the gas flow through the non-selected channels may be stopped, sealing that channel.

Gas from the selected channel is analyzed by one or several analyzers that may be arranged in a series or in parallel. Qubit supplies a wide range of analyzers for measuring CO2, O2, water vapor, H2, CH₄, N2O and other gases. Different analyzers are available across a wide range of gas concentrations and offer various features such as on board data acquisitions, rapid response times etc. We also offer gas conditioning columns, such as scrubbers for water and CO2 (A382).

Qubit Systems personnel have been designing gas exchange systems for over 30 years, and have published extensively on the physiology of respiration, photosynthesis and nitrogen fixation. We are committed to providing researchers with the most appropriate gas exchange system for a particular application at the best possible price, and we are always available to provide expert advice freely without obligation.   Contact QUBIT for furhter information.

References:

• M. R. Odiere, K. G. Koski, H. A. Weiler and M. E. Scott. Concurrent nematode infection and pregnancy induce physiological responses that impair linear growth in the murine foetus. Parasitology Vol 137,  p991-1002 (2010).

• Jumbo-Lucioni P, Ayroles JF, Chambers MM, Jorday KW, Leips J, Mackay TFC, DeLuca M. Systems Genetics analysis of body weight and energy metabolism traits in Drosophila melanogaster. BMC Genomics:11 p297- 309 (2010)

G400 Gas Mixing Systems

Key Features:

• Combine up to 9 gases using Qubit’s Mass Flow Controllers.
• Mass Flow Controller Ranges from 0.5 SCCM to +200 SLM.
• Mass Flow Controller accuracy 0.2 % full scale or 0.8% of reading.
• Multiple Alternate Gases may be used with each controller.
• 13 Different gas flow calibrations stored per controller.
• pure or mixed gases used as input gas.
• manual or software control of mixing.
• PC interface provided for software control.

Software:

• Combine 2 to 9 gases automatically.
• Instantaneous provision of required mixture with a mouse click.
• No calibration input required.Intuitive command structure.
• Automated flow implementation based on ratio and total flow.
• Error messages prevent selection out of range.
• Implement one gas mixture and queue the next.
• Store and retrieve settings.

Set up screen for 4 gas mixing system:

References:

• Charilaos Yiotis and Yiannis Manetas. Sinks for photosynthetic electron flow in green petioles and pedicels of Zantedeschia aethiopica: evidence for innately high photorespiration and cyclic electron flow rates. PLANTA Vol 232, Number 2, p523-531 (2010).

The G265 Gas Flow Controller and Monitor is a cost-effective way to track continuous flow rates, within the range of 200 to 2 000 mL/min. Gas may be supplied to the unit’s stainless steel luer input port from either a pump or pressurized source.

The Flow monitor of the G265 is individually calibrated and measures the mass flow of gas.  Specific calibration values are provided for each unit.  The flow of gas can be controlled by adjusting it  manually with a stainless steel needle valve on the fornt of the instrument.

To monitor the flow of gas G265 needs to be used with a data acquisition interface (i.e. C410 LabPro,  C610 LabQuest Mini or other) and software such as C950 Customized Gas Exchange Software, C901 Logger Pro Software, or any other data acquisition software that accepts a 0 – 5 V analog signal.

Specifications:

• power supply: 12V DC, 500mA
• size (h/w/l) cm: 5.7/13.0/13.2
• weight (g): 420
• materials: plastic (tan, black)
• operating conditions (temp, RH) <25 PSI
• warranty: 1years

The G264 Gas Flow Controller and Monitor is a cost-effective way to track continuous flow rates, within the range of 0 to 200 mL/min from a single channel. Gas may be supplied to the unit’s stainless steel luer input port from either a pump or pressurized source.

The Flow monitor of the G265 is individually calibrated and measures the mass flow of gas.  Specific calibration values are provided for each unit.  The flow of gas can be controlled by adjusting it  manually with a stainless steel needle valve on the fornt of the instrument.

To monitor the flow of gas G264 needs to be used with a data acquisition interface (i.e. C410 LabPro,  C610 LabQuest Mini or other) and software such as C950 Customized Gas Exchange Software, C901 Logger Pro Software, or any other data acquisition software that accepts a 0 – 5 V analog signal.

Specifications:

• power supply: 12V DC, 500mA
• size (h/w/l) cm: 5.7/13.0/13.2
• weight (g): 420
• materials: plastic (tan, black)
• operating conditions (temp, RH) <25 PSI
• warranty: 1years

The G249 Gas Flow  Monitor is designed to regulate gas flow through gas lines in a Multi-channel Gas Exchange System with up to 4 channels and flow rate through the system between 0 and 200 ml/min.

In G249 a single gas inlet port diverts the gas into a manifold system, supplying sample and reference gas lines. Flow through these is selected by adjustment of high quality needle valves and is monitored by separate, independent mass flow monitors in each gas line. This allows the researcher to monitor the flow rate through every singular chamber at all times.

Flow is monitored by our C950 Customized Gas Exchange Software using a high speed multiplexing facility that ensures only one analog channel of the data acquisition interface is used. Different flow ranges are available on request.

This instrument is designed so that it can work with gas exchange and data acquisition systems other than those manufactured by Qubit Systems.

Specifications:

• power supply 12V DC, 500mA
• size (h/w/l) cm: 13.0/20.4/25.3
• weight (g): 3100
• materials: sheet metal (black)
• warranty: 1 year

The G248 Gas Flow Controller & Monitor is designed to regulate gas flow through gas lines in a multi-channel gas exchange system with up to 4 channels and a flow between 0 and 2 L/min.

In G248, a single gas inlet port diverts the gas into a manifold system, supplying sample and reference gas lines. Flow through these is selected by adjustment of high quality needle valves and is monitored by separate, independent mass flow monitors in each gas line. This allows the researcher to monitor the flow rate through every singular chamber at all times.

Flow is monitored by our C950 Customized Gas Exchange Software using a high speed multiplexing facility that ensures only one analog channel of the data acquisition interface is used. Different flow ranges are available on request.

This instrument is designed so it can work with gas exchange and data acquisition systems other than those manufactured by Qubit Systems.

The G246 Gas Flow Controller & Monitor is designed to regulate gas flow through gas lines in up to 8 channel gas exchange system with flow rates between 0 and 200 ml/min.

 In G246 Gas Flow Controller & Monitor each single gas inlet port diverts the gas into a manifold system, supplying sample and reference gas lines. Flow through these is selected by adjustment of high quality needle valves and is monitored by separate, independent mass flow monitors in each gas line. This allows the researcher to monitor the flow rate through every singular chamber at all times.

Flow is monitored by our C950 Customized Gas Exchange Software using a high speed multiplexing facility that ensures only one analog channel of the data acquisition interface is used.

This instruments is designed so it can work with gas exchange and data acquisition systems other than those manufactured by Qubit Systems.

G245 Gas Flow Controller & Monitor – 8 Channels (0-2L/min) is designed to regulate gas flow through gas lines in a multi-channel gas exchange system (up to 8 channels) with a flow rate through the system between 0 and 2L/min.

In G245 a single gas inlet port diverts the gas into a manifold system, supplying sample and reference gas lines. Flow through these is selected by adjustment of high quality needle valves and is monitored by separate, independent mass flow monitors in each gas line. This allows the researcher to monitor the flow rate through every single sample chamber at all times.

the Flow of the G245 Gas flow Controller and Monitor is controlled by our C950 Customized Gas Exchange Software using a high speed multiplexing facility that ensures only one analog channel of the data acquisition interface is used. Different flow ranges are available on request.

This  instruments is designed so that it can work with gas exchange and data acquisition systems other than those manufactured by Qubit Systems.

The G244 Gas Switcher – 8 channel is designed for use in up to 8 channel gas exchange systems in which gases from up to 8 sample chambers are selected sequentially for analysis.

 In Open Flow Mode the G244 Gas Switcher takes gas from all 8 sample chambers, selects one line for analysis and vents the other lines to the atmosphere. The gas is then either selected for analysis or vented to the atmosphere. In Stop Flow Mode, the switcher seals the sample chambers for a user-defined period. The chambers are then flushed sequentially for gas analysis to provide time-integrated measurements of gas exchange rates. Plumbing the system for either mode is fast and easy.

The C950 Gas Exchange Software controls the G244 Gas Switcher, allowing any channel to be chosen for analysis in any sequence at  user defined frequency. Switching between reference and sample channels results in easy tracking and correction for any incidence of baseline drift. The Gas Switchers can be purchased with optional C250 Gas Switcher Software for stand-alone use. The C250 software provides all the switching functionality of Qubit Systems’ C950 Gas Exchange Software, but allows the switcher to be used in conjunction with any gas exchange system and/or data acquisition software you already possess. The switcher may also be provided with an on-board micro for use without a separate computer.

Each of our instruments is designed so that they can work with gas exchange and data acquisition systems other than those manufactured by Qubit Systems.

The Switcher is also available in a 4 channel version (G243).