Abstract: Many quartz tubes were used in electron paramagnetic resonance (EPR) experiments. These tubes were long and thin, and difficult to be cleaned. Here, an automated washing instrument for EPR sample tubes were designed for this purpose. The whole instrument mainly includes water purification machine, water storage tank, booster pump, air compressor, controller, solenoid valve pipeline and washing rack. Fully automatic washing EPR sample tubes was achieved through the Raspberry Pi computer, relay extension module and the Python Graphical User Interface (GUI) program by controlling the solenoid valve and the motor/lifter. The cleaning effects which the EPR sample tubes contained solid and viscous liquid were compared by using this washing instrument. The results demonstrate that the washing instrument exhibit excellent cleaning effect (no impurity signals in low temperature T =2 K) and high efficiency (cleaning and drying within 5 min), and it has high practical application value.

Key words: Automated, Washing, Magnetic resonance, EPR, Sample tubes