A Low-Cost Voltage Acquisition System for High Temperature Superconductor Measurement in 77 K

Currently, for quench detection, one of the most common methods is voltage measurement by using nanovoltmeters. Although the nanovoltmeter measurement accuracy is very high, there are only two measurement channels which cannot meet the requirement of multi-channels measurement. If multiple nanovoltmeters are applied together to monitor superconductors, the use-cost will be hard to accept. To reduce the costs of multi-channels voltage measurement for superconductors, a low-cost voltage acquisition system is designed in this paper. The core equipment of the system is a voltage acquisition board with multiple channels. To test the performances of the voltage acquisition system, a copper block immersed in liquid nitrogen, as a test sample, is measured by the voltage acquisition board. The results show the multi-channels voltage acquisition can be applied to interrogate weak voltage signals at low temperature. Furthermore, the voltage acquisition system is used to measure voltage changes of a high temperature superconducting (HTS) tape. The results coincide well with the HTS tape voltages measured by nanovoltmeters, which suggests that there is great potential of the voltage acquisition board for superconductor multi-channels voltage measurement applications.