The ProboStatTM is a cell for measurements of electrical properties, transport parameters, and kinetics of materials, solid/gas interfaces and electrodes under controlled atmospheres at high temperatures. The versatile construction and accessories of the present system are based on years of development and experience in the Kofstad/Norby group at the University of Oslo. A ProboStatTM system may offer a cost-effective alternative to developing and building your own cell for studies, characterization and testing of inorganic materials, electroceramics, fuel cell components, membrane materials, etc.

Brief description

The sample under test rests on a ca. 50 cm long support tube of alumina, inside a closed outer tube of alumina or silica. The sample can be contacted with 2, 3 or 4 electrodes of e.g. platinum, using disk, van der Pauw, or bar geometries. A spring-loaded alumina assembly holds the sample and electrodes in place. 16 electrical feedthroughs allow use of 4 shielded electrode leads, surface guard, and up to three thermocouples (e.g. for Seebeck coefficients). Electrical connections are made via standard multiconnector, coax cables suitable for standard impedance spectrometer connectors, and standard thermocouple compensation cables. Gases can be fed in single or dual chamber modes directly onto or from electrodes, allowing measurements under controlled atmospheres, transport number measurements in gradients, and testing of fuel cell, pump, and sensor components. Gas supply is via Swagelok quick-connects. Suitable for >4 cm diameter, <80 cm long tubular furnaces.

Materials properties measured and applicable methods

• Conductivity vs T, pO2, pH2O, etc.
• DC, AC, impedance spectroscopy
• Dielectric properties, loss, etc.
• Disk, van der Pauw, and bar geometries
• 2, 3, and 4 electrodes
• Ionic transport number
• Proton transport number
• Seebeck coefficient
• I-V-characteristics
• Fuel cell components and single cell testing
• Electrode kinetics
• H/D isotope effects
• Electrochemical pumping, gas permeation and electrocatalysis with gas analysis (e.g. GC or MS) on outlets
• Sensor testing
• Hot zone accessories (noble metals and ceramics) for most methods can be supplied.
• Poling of ferroelectrics possible with the high-voltage (kV) version

Close-up photos show example of connection to disk samples for impedance or concentration cell (transport number or fuel cell) measurements. The schematics show principle of spring loads and regular 2-electrode 4-wire setup with dual gas supplies and thermocouple. Part of base unit with feedthroughs is shown in the photo below.

Specifications

• Outer tube diameter: 40 mm
• Overall length: 75 cm, shorter versions available (-10, -20, -30 cm)
• Single end cell assembly
• Sample fixation: spring force via alumina rods
• All hot-zone electrode leads detachable via feedthrough mini-connectors
• Support tube systems from 10 to 24 mm diameter detachable
• For up to 24 mm diameter disk samples
• For up to 50 mm long bar samples
• Temperature: typical long term: <1400 °C; shorter term: <1600 °C
• Atmosphere: Oxidizing or reducing, wet or dry, from small overpressure to low vacuum6 BNC electrode connections for impedance spectrometers etc.
• Internal shields bridging (for SI 1260 , HP 4192A etc.), ground and guard switches
• 3 thermocouple connections
• 4 Swagelok gas quick-connects to 1/8'' tubing (other connections on request)
• Standard materials: Alumina AL23, Pt, Pt10%Rh, Ni-plated brass
• Water cooling (or heating) of cold end base unit is possible
• Spare parts supply, also of hot zone consumables