Field Strength Meter-Membrane Switch

Label:Field Strength, Single Channel Measurement, LCD Interface

Jul 15, 202110360

Field Strength Meter-Membrane Switch
The field strength meter usually refers to an instrument used to test the field strength. The unit of field strength is V/m. In principle, the level meter (or voltmeter) measures the voltage at the input port of the instrument, and the voltage measured by the field strength meter is the voltage caused by the antenna at a certain point in the air. Strictly speaking, the field strength meter consists of a level meter and an antenna.

It is mainly used to measure the electric field intensity of high-voltage power transmission and transformation systems, power distribution rooms, induction furnaces, subways, electric locomotives, medical equipment, drying equipment, computers and other workplaces with electromagnetic radiation. It can be used for labor protection, occupational disease prevention, environmental testing, environmental sanitation, etc.

The main features of the field strength meter:

1. Small size and high precision;
2. The digital display can directly read the V/m number, which is simple and intuitive;
3. The measurement frequency is wide, and the frequency response error is small;
4. Single channel measurement with field strength meter

Press the CH/F key, the instrument switches to single-channel measurement mode, the LCD interface is as follows:

The main features of the field strength meter

At this time, the current channel number is displayed at the bottom left of the screen, the video carrier frequency value of the current channel is displayed at the bottom right, the video carrier level of the current channel is displayed in the middle of the left screen display, and the V/A value of the current channel Shown on the right. By pressing the up and down keys, the user can increase or decrease the number of channels.

How to use the field strength meter:

1. Connect the cable correctly, and the connecting cable should not be too long. If a long cable is necessary, the cable loss must be added to the meter's reading, especially in the high frequency range.

2. The field strength meter not only measures the image carrier level, but also measures the carrier level of the FM sound broadcast signal. Therefore, the signal level used should include the sound carrier level and the image carrier level. The sound carrier level is defined as the effective value of the unmodulated sound carrier voltage on the 75 Ω terminal, expressed in dBμV. The video carrier level is defined as the effective value of the video carrier voltage at the modulation envelope peak (synchronization head) on the 75 Ω terminal, expressed in dBμV. Therefore, the detector for measuring the level of the image carrier should be a peak detector.

3. The temperature of the operating environment. Pay attention to heat preservation measures when using in winter. When using it in summer, try to avoid placing the instrument directly in the sun, otherwise the reading error will greatly exceed the range of technical indicators.

4. When using the field strength meter, move it frequently. Avoid collisions as much as possible to avoid damaging the casing of the instrument and the accuracy of pitching.

5. The field strength meter must be periodically measured or compared with a field strength meter that has been specifically measured to avoid misjudgment due to inaccuracy of the instrument.