title: [A device for the display of the distribution of the high-frequency electromagnetic fields used in medicine].
abstract: A device has been developed to indicate high-frequency electromagnetic fields. A miniature neon filament wherein self-maintained normal glow discharge is turned on is used as a probe placed in the required point of the field. The neon filament acts as one of four resistors that form a bridge circuit. On exposure of the neon filament to its turned-on discharge of external electromagnetic radiation, the balance of the bridge circuit is impaired, which is recorded by a microammeter connected across a diagonally opposite pair of bridge junctions. To eliminate a non-linear dependence of microammetric indices on the studied magnetic field strength and to enhance the sensitivity of the device, a current regulator and an operational amplifier were used in its construction. The circuit diagram of the device is given by indicating the types and rating of the elements used. The diagram provides protection of the microammeter from reverse voltage and prevents the input of the amplifier from voltage overload. Provisions are also made for its protection from alternating field induction and for reduction in feed instability of the operational amplifier.
authors.forename: S I
authors.initials: SI
authors.lastname: Masychev
mesh_terms: D004599:Electric Stimulation Therapy; D004574:Electromagnetic Fields; D004582:Electronics, Medical / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D008280:Magnetics / Q000627:therapeutic use; D009356:Neon
chemical_list: D009356:Neon