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)

The S147 Rapid Response O2/CO2 Analyzer combines both a laser diode O2 sensor and an infrared CO2 detector. This analyzer is designed for measurements of rapid changes in O2 and CO2 such as those occurring  during O2 uptake and CO2 production from breath by breath measurements of human respiration.  Please check Qubit’s BBB1LP Breath by Breath Respirometry Package

The S147 Rapid Response O2/CO2 Analyzer has a built in pump which is set at 400 mL/min to draw samples in through the “Gas In” port located on the front of the analyzer. Gases exit the analyzer from the front panel from the “Exhaust” port. There are controls for calibrating the O2 and CO2 sensors on the front panel including the “Zero” and “Span”. You should only adjust the “Span” for CO2 and O2 if you have calibration gases at hand to perform the calibration. Also located on the front panel of the analyzer are an “On/Off” switch with an indicating LED Light and a pump On/Off” switch with an indicating LED Light. The pump speed control should not need adjustment.

The back panel of the S147 Rapid Response Analyzer contains the power jack (115/220 VAC, 115W), an exhaust port for the fan and an Analog Outputs jack. To this jack you should connect the included data collection cable which connects to a data acquisition system. We recommend the C901 LoggerPro data acquisition software for data collection.

The S147 Rapid Response O2/CO2 Analyzer is supplied with F250 Flow meter and asorted connectors and tubing.

Sample of resting breath O2 and CO2 data:

Specifications:

CO2 sensor:

• Operating Principle:  Infrared Spectroscopy
• CO2 Range:  0-13%
• Accuracy: +/-2 mm Hg @ < 5.0% CO2, < 10% of reading @ > 5.0% CO2
• Operating Temperature:  5o°C to 55°C
• Power Consumption:  335 mW
• Response Time:  Detector: 28 ms , System: 100 ms (typical)
• Breath Rate:  2 – 150 bpm

O2 sensor:

• Operating Principle:  Laser Diode – Optical Absorption
• Range:  5% to 100%
• Resolution:  0.01 Vol.% O2
• Accuracy:  0.1%
• Noise (80 ms average):  0.1%
• Linearity:  0.2 Vol.%
• Drift (2 hrs):  0.1 Vol.%
• Response time (T90):  130 ms @ 200 mL/min flow
• Operating Temperature:  0^oC to 50^oC
• Relative Humidity:  5 to 95%
• Operating Pressure:  25 to 115 kPa

Q-S121 H2 Gas Analyzer is a flow through analyzer for measurements of H2 gas in 0-2000ppm range.  Linear response in the low range (0-20ppm) with ppb resolution.  The Q-S121 has a Tin-dioxide (SnO2) semiconductor sensing element.  Q-S121 can be used to measure Nitrogenase activity as H2 evolution in uptake hydogrenase (HUP) minus symbioses of legumes.  The Q-S121 H2 Gas Analyzer may also be used to monitor the hydrogen consumption of organisms that have the HUP enzyme.  This H2 Analyzer is a vital part of the Q-Box NF1LP Nitrogen Fixation Package.

Specifications:

• Range: 0 to 2000 ppm H2
•  Output: 0 to 5 V  analog to digital interface
• output sensitive to O2 concentration and flow rate
• warranty: 1 years

References:

• Catherine A. Osborne, Mark B. Peoples and Peter H. Janssen. Detection of a Reproducible, Single-Member Shift in Soil Bacterial Communities Exposed to Low Levels of Hydrogen. Applied and Environmental Microbiology Vol. 76, Number 5, p1471-1479 (2010).

• Stephanie A. Fischinger, Marieta Hristozkova, Zaman-Allah Mainassara and Joachim Schulze. Elevated CO₂ concentration around alfalfa nodules increases N₂ fixation. J. Exp. Bot. Vol  61, Number 1, p121-130 (2009).

• Mark B. Peoples, Paul D. McLennan and John Brockwell. Hydrogen emission from nodulated soybeans [Glycine max (L.) Merr.] and consequences for the productivity of a subsequent maize (Zea mays L.) crop. Plant and Soil Vol 307, Numbers 1-2, p67-82 ( 2008).

• Jiamila Maimaiti, Ye Zhang, Jing Yang, Yan-Ping Cen, David B. Layzell, Mark Peoples and Zhongmin Dong. Isolation and characterization of hydrogen-oxidizing bacteria induced following exposure of soil to hydrogen gas and their impact on plant growth. Environmental Microbiology Vol 9, Issue 2, p435–444 (2007).

• Y.-P. Cen and  D. B. Layzell. Does oxygen limit nitrogenase activity in soybean exposed to elevated CO₂? Plant, Cell & Environment Vol 27, Issue 10, p1229–1238 (2004).

• Z. Dong, L. Wu, B. Kettlewell, C. D. Caldwell and D. B. Layzell. Hydrogen fertilization of soils – is this a benefit of legumes in rotation? Plant, Cell & Environment Vol 26, Issue 11, p1875–1879 (2003).

• Z. Dong and D.B. Layzell. H2 oxidation, O2 uptake and CO2 fixation in hydrogen treated soils. Plant And Soil Vol 229, Number 1, p1-12 (2001).

The S120 Dissolved Oxygen Probe with built in amplifier is ideal for field use and measuring oxygen concentration in larger containers. The electrode has integrated temperature compensation so that calibration can be done in the lab. The probe can then be used in the field without the need for recalibration or temperature correction calculations.

Specifications:

• Range: 0 to 15 mg/L (or ppm)
• Accuracy: 0.2 mg/L
• Resolution (with 12-bit interface): 0.014 mg/L
• Response Time: 95% of final reading in 30 seconds, 98% in 45 seconds
• Temperature Compensation: Automatic from 5-35oC
• Pressure Compensation: Manual, accounted for during calibration
• Salinity Compensation: Manual, accounted for during calibration
• Minimum Sample Flow: 20 cm/second
• warranty: 2 years

Calibration of S120 Dissolved O2 Probe is easy! All of the requirements for calibration are supplied with the probe. Using C901 Logger Pro software, the probe can be calibrated in units of mg O2/L, % Dissolved Oxygen, ppm or whatever units are appropriate

For many oxygen electrodes, changing the membrane is an awkward process. With the S120, the membrane cap is an integral part of the probe and it and is easy to change (screws on to the end of the probe). A spare membrane cap is included with the probe and additional caps can be ordered separately.

• Extremely high stability – zero adjustment is never needed, calibration seldom
• No regular maintenance needs. The robust membrane, 50 μ thick, is easily cleaned, but if damaged can be replaced by anyone – at negligible cost
• Correct measurements with flow as low as 1 cm/s
• Based on a chemical principle superior of that of traditional DO probes
• Galvanic type – True zero
• Build-in temperature compensation
• 7 m cable

Probe includes Maintenance kit (D904-KIT):

• 10 spare membranes
• Polishing pad
• 50 ml electrolyte fluid.

• Galvanic cell, no power supply needed
• Built-in temperature compensation
• Excellent long-term stability
• Tough membrane can be wiped clean with a cloth
• Probe does not need regular service or renovation.
• Membrane replacement tool included

Optional maintenance kit (D902-KIT) includes 10 spare membranes, a pre-fitted membrane cap and 50 ml electrolyte fluid.

• Galvanic cell giving a 0-25 mV output (no power supply needed)
• Build-in temperature compensation
• Excellent long-term stability
• Tough membrane can be wiped clean with a cloth
• Probe does not need regular service or renovation
• Membrane replacement tool included

Optional maintenance kit (D901-KIT) includes 10 spare membranes, a pre-fitted membrane cap, a polishing pad and 50 ml electrolyte fluid.

The D701 is a polarographic O2 electrode Probe (identical in design to the E-5046 electrode from Radiometer) consisting of a combined platinum- and silver/silver chloride electrode mounted in an electrode jacket and covered by a 20 um thick membrane of polypropylene. A reservoir of phosphate buffer and potassium chloride is trapped inside the electrode.

When a polarizing voltage of approximately 630 mV is applied to the platinum cathode, a current proportional to PO2 will be generated by reduction of the oxygen diffusing towards the cathode.

Included supplies:

• Electrode body & O-ring
• Oxygen membranes (15/pkg)
• Membrane O-ring (10/pkg)
• Membrane mounting tool
• Oxygen internal fill solution (electrolyte) (60 mL)
• Rubber end cap

Required supplies (not included):

• D607 Polarographic amplifier
• Nitrogen gas or sodium sulfite (Na2SO3)
• Distilled water, alcohol and lab wipes

Specifications:

The D202 Oxygen Regulation System is a complete system that will monitor and regulate oxygen saturation in sea or fresh water, e.g. for normoxic, hyperoxic or hypoxic control in fish tanks, aquariums etc.

A large display, two digital relays for valve control, menu-driven settings and an analog output for data acquisition, makes this system user friendly and well suited for a range of lab applications.

Example – Hypoxic control. The oxygen set point value is compared with measured values. If the oxygen saturation is higher than the set point value the digital relay activates the solenoid valve to open for injection of nitrogen gas (gas bottle not included).

System Includes:

• D201 controller instrument
• D901 Miniature Galvanic DO2 probe and maintenance kit
• Preamplifier with galvanic isolation
• Solenoid valve for O2 and N2 (24, 110 or 230V)
• Air tubing (6/4 mm)
• 1/8″ fittings
• Ceramic diffuser
• Analog output (0 – 5V)

System Excludes:

• Pressure bottle and regulator for N2 or O2

Suggested set up of D202:

Controller (D201) Specifications

IMPORTANT: DO NOT connect relays to >500W equipment (max 2 A, 250 V).

Mini-DO probe(D901) specifications:

S500 Metabolic Analyzer (Metabox) is the first combined O2 and CO2 analysis system that allows you to take both your lab and your office into the field.  This system is customized to your O2 and CO2 range of analysis.  The system can be provide with only O2 or CO2 analyzer.  The integrated Tough-book hybrid PC provides hours of operation and comes with Qubit’s C950 gas exchange software that may be customized for your specific requirements ( Contact Qubit). View all your data graphically as they are collected, not just a digital display of values, and use whatever additional programs you wish to crunch numbers and prepare reports. The S500 Metabox gives you perfect flexibility and unsurpassed accuracy packaged in a rugged, easy to carry, waterproof case.  Use it in the field (battery pack A247 or A248 optional) or in the lab for your gas exchange measurements.

Features:

• Combined O2 and CO2 Measurements
• Open and Closed System Gas Analysis
• Integrated Gas Pumps
• integrated data acqusition interface
• Integrated Mass Flow Monitors
• Includes Panasonic Tough-book PC
• rugged, waterproof case

Applications:

• Plant photosynthesis and respiration
• Insect Respirometry
• Animal Respirometry
• Soil Respiration
• Atmospheric Monitoring
• Gas Exchange Quotient