​Coulometric Titration System CoulTCell - CoulTell

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The CoulTCell is a coulometric titration setup for measurements of oxygen nonstoichiometric

properties of materials at high temperatures, and in different partial pressure of oxygen.

The output of these experiments can be used for the investigation of the redox behavior

of nonstoichiometric materials.

 

The system consist of two parts; the cell and the instruments package, to be aquired

together or separately. The cell is brass and alumina made, two 8% mol partially

stabilized YSZ electrolytes, S-type thermocouple, Swagelok valves and bulkheads

and 8mm water cooling- in and outlets. Accessing sample is easy by detaching the

outer tube by unscrewing 4 short bolts. Equipped with several spare crucibles. The

design is improved version of equipment resulting from years of research development

and experience by research fellows Dr. Egil Bakken and Mehdi Pishahang under

supervision of professors Svein Stølen and Truls Norby at the University of Oslo.

 

The instruments package consist of precission power source and a multimeter,

controlled by a computer software. The instruments are enclosed in a compact

casing, connecting to the computer wuth USB cable and to the cell with BNC

cables (cables included).

 

The system offers a cost-effective alternative to developing and building your

own cell for studies, characterization and testing of inorganic materials for

purposes like fuel cell components, membrane materials, chemical-looping

oxygen carriers, etc. All units are tested and validated with strict requirements.

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Download brochure

 

Brief description of the cell

The sample is placed in an alumina crucible, hanging from the sample holder rods

by platinum wires, deep inside the furnace. The sealing system consisting of a

gasket and front flange couplings are placed on the top of the setup and above

the furnace. Water cooling system keeps the joints and sealing components

protected. By giving feedback to the furnace power supply, the S-type thermocouple

implanted into the setup controls the actual temperature of the sample and the solid

electrolytes. The gas inlet and outlet (Swagelok bulkheads) can be used to flush the

entire setup with the desired gases (e.g. air, O2, or N2). Oxygen pump solid electrolyte

sucks oxygen from the setup, and therefore the sample, while oxygen sensor solid

electrolyte monitors the changes of the oxygen partial pressure simultaneously. The

instrument package and software supply and measure the voltage and current of the

solid electrolytes. The interface between the electronic controllers and the user is

applicable by the software which shows the state of the system graphically and logs

the output every 5 seconds. Desired gases can be fed in one or both of the solid

electrolytes, providing the chance to adjust the chemical leakage. 

 

Cell specifications

• Outer tube diameter: 30mm

• Overall length: <700mm

• Chamber length: 300mm

• Water cooling coil

• Gas inlet and outlet Swagelok bulkheads

• Separate gas chambers for each solid electrolyte

• Sample: ≈1.2 gr

• Solid electrolytes: 8% mol partially stabilized YSZ

• Temperature: 850 ºC - 1100 ºC

• Atmosphere: Mixtures of oxygen and nitrogen (From pure O2 to pure N2)

• Oxygen partial pressure range: from log(pO2)=0 to log(pO2)= -18 (at 950 ºC)

• Leakage current at 900 ºC: 15 μA at log(pO2)= -1.5

• Electrode+Electrolyte resistance at 900 ºC: 5Ω      外管直径：30mm
   

Instrument package specifications

• Instruments Keithley 2000 DMM with scan card, Keithley 2401 SMU

• Sourcing precision 10pA

• Plug and play software & instrument

• Adjustable PI control

• Real time on screen plots: Pump current, Sensor voltage, Furnace temperature, Pump voltage.

• CSV data exports

 

Additional equipment required

• Water coolling system
  5mm inner diameter Silicon hose with reliable water supply. Recirculating system with a pump and overflow system recommended. Included in the quote only by request.

• Furnace
  Vertical tube furnace with tube diameter about 40mm, length of 500mm to 700mm. Suitable furnace included in the quote only by request.

• Computer
  Windows operating system, 1 free usb port.

      

Measurement instrumentation
The setup includes both multichannel voltmeter and precision sourcemeter

integrated into a nice instrument casing.     

 

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Easy connections    

BNC cables connect the instrument to the cell and USB cable instrument to

computer.     
 

 

 

 

Tailor made software  

The software will run on any computer with USB port and Windows operating system.

      

 

 

 

 

 

 

 

Easy sample access by detachable outer tube

On this picture: Cell flush out valve, water cooling loop, O-ring seal, 4

threaded screw slots.