[en] A voltage divider and a Rogowski coil have been developed for measuring currents and voltages of a pulsed X-ray device. The voltage divider is a two stage divider using an aqueous copper sulphate solution, and has been tested up to 300 kV, the highest value expected of the output voltage of the device. Its response-time is measured to be less than 1 ns and the net division ratio, 1 : 1666. The measured response-time of the Rogowski coil is somewhat shorter than 1 ns, and the sensitivity is about 1.04 x 10⁴ A/V. (auth.)