Carry out measurement of the electromagnetic field in two directions. The first – find its frequency, using the vibrator of Hertz or an oscillatory contour. For this purpose adjust them in a resonance with the external electromagnetic field and calculate their own frequency. The second is its intensity. For rough measurement of intensity use the inductance coil (solenoid). For more exact – special devices.
It is required to you
- - Hertz vibrator,
- - oscillatory contour with a possibility of change of settings,
- - copper wire,
- - iron core,
- - set of devices for measurement of magnetic and electric fields.
Instruction
1. Determination of frequency of the electromagnetic field Take the Hertz vibrator. It is a copper core, with balls on the ends into which rupture the Rumkorfa coil is inserted (two windings on one core). At introduction it to the electromagnetic field regulate a core gap until in it begin to slip sparks. By means of the reference book on these parameters find the frequency of operation of this vibrator, it also will be the frequency of the external electromagnetic field.
2. In the second case take an oscillatory contour with the coil of small inductance and the high-capacity condenser. Turn on the ampermeter in this oscillatory contour and (changing its parameters, for example, increasing or reducing capacity) measure at what values on it there is the greatest current. It will be observed at coincidence of own frequency of a contour to the frequency of fluctuations of the electromagnetic field. This reception is used in radio receivers, and therefore it is possible to take a contour from them. Devices measure inductance of the coil and capacity of the condenser at which the resonance is observed, then take a square root from the work of inductance and capacity and increase result by number 6.28. Divide number 1 into calculation result. Frequency of the external electromagnetic field in Hertz will be result.
3. Determination of intensity of the electromagnetic field If is known that in this point of space there is an electromagnetic field, take a copper wire of the big section about 1 m long, reel up it in the form of the solenoid (several isolated rounds) and to conclusions (ends of the conductor), attach the voltmeter. Variation magnetic field which is a component of the electromagnetic field will excite in the EMF conductor, measure it by means of the voltmeter. The more indications of the voltmeter, the more intensively field. Special measuring instruments of magnetic field can define its intensity in various frequency ranges. Bring the device sensor in the field and on its screen its parameters will appear.