| 摘要 |
The invention relates to the field of technical means for protecting high-frequency measurement apparatus from the action of high-frequency external noise and can be used for screening magnetocardiograph systems operating in unscreened spaces. The device comprises an electromagnetic screen consisting of a lower part, namely a screen for screening detectors, and an upper part, namely a screening cover for screening electronic preamplification units, which is mounted tightly on the lower part. The lower part of the screen is formed on a supporting frame consisting of two coaxial cylinders connected in series without a base, with a multilayered fabric radio-absorbing material on a graphite substrate being fixed to the outer surface of said supporting frame, while the base of the frame of the screen is closed by one layer of fabric radio-absorbing material. The screening cover is formed on the frame in the form of a cylinder from plastics, which is closed by the upper plane of the cylinder, with a multilayered fabric radio-absorbing material being fixed to the external surface of said supporting frame, while laminations of copper foil for ensuring electrical contact between the lower and upper parts of the electromagnetic screen are fixed to the lower edge. An opening for routing a cable to the electronic preamplification units is formed in the lateral surface of the upper part of the electromagnetic screen. The device is inexpensive and eliminates excessive noise caused by the screens. |
