Oxytherm – Oxygen Electrode


Liquid-Phase Photosynthesis & Respiration Measurement

  • Peltier oxygen electrode unit with integral thermoelectric temperature control
  • Compact design with integral electronics and magnetic stirrer
  • Computer controlled oxygen electrode system with direct on-screen display of traces
  • PC operated Oxytherm electrode control unit suitable for liquid-phase measurements of photosynthesis & respiration
  • Custom Windows® software for instrument control and data analysis
  • System expansion to 8 channels via purchase of additional components


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  • The Oxytherm oxygen electrode control unit is designed to provide PC control of oxygen uptake or evolution  measurements across a broad range of applications from studies of mitochondrial and cellular respiration to measurements of isolated chloroplast suspensions in photosynthesis research.

OXYT1-Oxytherm Electrode Control Unit


  • Oxytherm operates in conjunction with user-friendly O2view data acquisition and system configuration software to provide an effective tool for the measurement of oxygen signals from the S1/MINI Clark type electrode disc with quick and easy system calibration and configuration.
  • Oxytherm is supplied with a sophisticated temperature controlled oxygen electrode chamber consisting of a fan assisted Peltier Element with a large surface area and thermally insulated reaction vessel in order to achieve rapid equilibration and maintenance of any user-selected temperature within the range 3-40°C (assumes ambient temperature of 20°C). This provides freedom to site the unit away from the traditional laboratory setting and ensures that temperature related artefacts are minimised during measurement.
  • The Oxytherm oxygen electrode control unit comprises a robust yet lightweight enclosure containing the integrated electronics and magnetic stirrer. The electrode chamber consists of a similarly constructed enclosure containing the 10mm precision bore borosilicate glass reaction vessel which is well insulated in order to minimise heat loss through the casing and also provides the capability to perform both light and dark reaction measurements.
  • There is also a viewing port in the front of the electrode unit with an illuminating white LED controlled by a push button on the side of the unit. Both control box and the electrode unit are powered from a single external 12V DC power supply.
  • An Oxytherm system may be configured as a single or multi-channel setup in order to make comparative measurements of oxygen from multiple samples. Simultaneous recording of an optional auxiliary input signal (e.g. temperature, pH, fluorescence, TPP+ or other specific ion electrodes etc) is also possible using the OXY/PHA amplifier unit coupled via the auxiliary input on the rear of the Oxytherm oxygen electrode control unit.
  • A system comprises a minimum of one (maximum of eight) control units linked together in a chain to the serial port of a Windows® PC. Oxytherm control units may be freely interspersed with Oxygraph oxygen electrode control units within a multi-channel system.
  • The control unit connects to a PC via the serial port and uses bidirectional RS232 communications for instrument control from the PC and data acquisition to the PC. There is no requirement for separate loggers, internal PC interfaces or A/D cards. Laptop or notebook computers are therefore just as suitable as a desktop PC and provide a highly portable, compact system whenever bench space is limited.

S1/MINI oxygen electrode disc


  • The S1/MINI oxygen electrode disc has been designed exclusively for use in the Oxytherm Peltier Electrode Chamber and is based on the standard S1 Clark type polarographic oxygen electrode disc.
  • When fitted, the dome of the electrode disc forms the floor of the electrode chamber reaction vessel providing a sensitive and rapid response to small changes in oxygen tension within the sample.
  • The electrode disc comprises a central platinum cathode and a concentric silver anode. Preparation of the electrode includes the addition of electrolyte and the application of a thin oxygen permeable P.T.F.E. membrane to the electrode dome.
  • Once prepared and positioned in the electrode chamber, the disc is connected to the Oxytherm control circuitry which applies a small polarising voltage between the platinum and silver electrodes. In the presence of oxygen, a small current is generated proportional to oxygen activity in the sample.
OXYT1 Oxytherm  Electrode Control Unit
Measuring Range 0 – 40% oxygen
Min. O2 Resolution 10 x 10-6 μmols/ml at 20 °C
Magnetic Stirrer 150 – 900rpm
Polarising Voltage 700mV
Gain  up to x50 (10 bit resolution)
Back off 12 bit resolution
Integral Test Resistor Yes
Signal Inputs Electrode disc Auxiliary input
 Acquisition Rate  0.2 – 10 readings per second
Communications Bi-directional RS232. USB Via HAN/USB adapter (supplied)
Dimensions 250 (w) x 126 (d) x 136mm (h). Weight: 1.27Kg
Power Supply 95 – 260V universal input mains supply. Output 12V DC 2.5A
Peltier Electrode Chamber Temp range: 3 – 40°C (25°C ambient).
Response time: <10 min,
Accuracy: +/- 0.5°C.
Sample volume: 0.2-2.5ml.
Optical port for FMS fluorimeters, Front viewing window.
Dimensions: 132 x 100 x 90mm
S1/MINI Oxygen Electrode Disc
Electrode Type Clark type polarographic oxygen sensor
Electrode Output 1μA at 21% O2.
Residual current Typically 0.02μA in 0% O2
Response Time 10 – 90% typically < 5 seconds
Oxygen Consumption Typically <0.015mol hr-1

Accessories & Spares Supplied

  • A2 Membrane applicator
  • S2/P Magnetic followers
  • S3 Spare reaction vessels
  • S4 30m roll of PTFE membrane
  • S7B Spare O-rings for Peltier electrode chamber
  • S16 Electrode cleaning kit
  • HAN/USB RS232 – USB adapter