Coated Conductor Cylinders Ltd

Home 3-Cs Concepts Inspector Hall Contact us


Inspector Hall


Rapid testing for superconducting samples

Is the optimisation of your HTS process parameters being slowed down by delays in measuring electrical properties?


Do you want to reduce the reliance on four-terminal transport current measurements and using costly and complex electrical and magnetic property measuring instruments?


If so you will be interested in the 3-C’s "Inspector Hall" rapid test equipment which gives a simple, inexpensive estimate of Jc and Tc .

Inspector Hall Rapid Test Unit

Inspector Hall equipment showing the controller,  magnetic sensor unit and sample holder. The  switches and potentiometers are used during set-up procedures to offset the earth’s field and stray fields – including any magnetisation of the substrate – and to “zero” the field due to the coil.

Operating Principle


Inspector Hall is designed specifically for laboratories developing thin film superconducting materials. The sample sits in a liquid nitrogen bath between a DC electrical excitation coil and a high performance magnetic field sensor. When below the superconducting transition temperature, Tc the sample partially shields the sensor from the magnetic field of the coil. As the liquid nitrogen evaporates, the sample warms and passes through Tc and thus more magnetic flux from the coil reaches the sensor. The change in magnetic flux is related to the product of superconducting critical current density Jc and the superconducting film thickness. The sensor reading therefore provides a fast comparative measure between samples of the degree of superconductivity in your samples and also a value for Tc.


  • Main control unit containing calibration controls and operating switches. Display showing magnetic sensor output and current to excitation coil.

  • Sample holder, excitation coil and type K thermocouple contained in a liquid nitrogen reservoir.

  • Digital thermometer to monitor sample temperature.

  • Magnetic sensor unit providing precise location to the sample holder assembly.

  • Calibration controls to offset the effect of stray fields and fields from the coil reaching the sensor around the sample.


  • Provides a simple means of comparing the superconducting properties of thin film samples between 77K an 100K so that the effect of changes in film composition, morphology etc. can be rapidly established.

  • An approximate measure of the superconducting transition temperature.

  • Sample size required is small – just 1 cm2.

  • No electrical contact with the sample necessary avoiding the complications and sample preparation requirements for four-terminal measurements.

  • Does not rely on a completed current percolation path so imperfect samples containing cracks which block current flow can still be measured.

  • Eliminates errors due to magnetisation and AC loss effects in the substrate material which can occur when using conventional AC measurements.

Inspector Hall - find out more


Inspector Hall provides a fast, simple and inexpensive way to establish basic superconducting properties leaving you free to concentrate on optimising material composition, morphology and processing conditions. It is supplied with an operator's manual and has one year's warranty.