Wuhan where to sell analog TV Field Test Instruments? Analog Signal Level Meter What makes a good? 0371 -55,676,313 Business QQ: 2417674438 Strength Meter name suggests is to measure the field strength of the instrument. Strength Meter magnitude is μV / m for the unit, it contains a unit of length m. In principle, the level meter (or voltmeter) which measure the voltage value is the input port of the instrument, while the Level Meter measures the voltage (or called electric potential) is a point the antenna in the air induction voltage. Strictly speaking, the field intensity is determined by the level meter and antenna. Expounding field strength of the electric field intensity field short, it is the antenna at a point in space is the size of the sensor signals to characterize the electric field strength at that point. The unit is microvolts / m (μv / m), for convenience, is also useful dBμv / m (0dB = 1μv). Edit this paragraph field strength measurements of field strength measurements as shown. Antenna polarization of the signal in the air in the same direction to achieve maximum induction signal, generally available radio frequency (RF) of the RMS level meter type (voltmeter) to measure. When the line is a good match, the meter reading value of the level of the instrument input port (usually 50Ω or 75Ω) obtained RF voltage Er (dBμv). Er can be represented by the formula Er = E + Ga +20 lgle-Lf-6 --- (1) Er reading of the instrument input level (dBμV); E is the electric field strength (dBμV / m); Ga receiving antenna Gain (dB). If a half-wavelength dipole antenna Ga = 0dB; le receiving antenna effective length (λ / π); Lf to receive feeder loss (dB); currently cite specific examples: Let the test frequency 228.25MHz (λ = 1.31m) then 20lgλ / π = 20lg1.31 / π ≈-7.6dB; receiving antenna is a half-wavelength dipole antenna, Ga = 0dB; Lf selected attenuation 10dB/100m cable, length 10m, practical attenuation 1dB; instrumented level is 15dBμV. The above data into (2) type, that have E = Er-Ga-20lgle + Lf +6 = 15-0 - (-7.6) +1 +6 = 15 +7.6 +1 +6 = 29.6dBμV / m Edit this paragraph distinction is well known that the level meter in decibels (dB) as a unit, such as dBμV, dBmV, dBm, which is based voltmeter volts (V) as a unit, such as V, mV, μV, KV and so on. In fact, the level voltages are the same physical quantity, therefore, on many occasions both units at the same time marked an instrument, which in a sense, but also voltmeter level meter, level meter is level pressure table, but it is customary to call it separately. The field strength of the current market point of view, they are also the technical specifications of the level meter antenna apart. Such as Japan Anritsu ML524 Strength Meter host is on a level table gives the technical indicators, frequency range, sensitivity, level measurement range, level test accuracy, the antenna MP534A, MP666A as an option, according to the band gives technical indicators and antenna factor. At present, commonly used in the wireless field produced PTK3201 Strength Meter Korea, it is also given by the level meter indicator, the frequency range 0.1 ~ 2000MHz, sensitivity 0.3mV, etc. are given to the instrument input port, there is a whip antenna installed, there is no antenna factor, only qualitative measurement signal field strength is small, if you want to determine dBμV / m field strength, they have matching measurement antenna. Thus, the level and field strength level meter and Strength Meter is a big difference. But on some occasions are often confused, especially in our country within the cable industry, cable television signal is a measure of the sync tip level to measure, for the unit to dBμV, this should be called the TV signal level meter, level meter, or However, beginning from the Chinese to engage in common antenna, I do not know how they called it Strength Meter. The world's first TV Signal Level Meter is a Japanese Leader produced LFC944, Lida original television signal level meter, and since then a lot of people call it Signal Level Meter, the author has repeatedly in the CATV industry proposed level meter should be called, perhaps too many people called, is still called the Field Strength Meter, even when foreigners in China had approved the exchange of call, and that only by mistake to miss. About Cable scope "misnomer," the field strength meter, I have it classified as a TV Signal Level Meter, television spectrum image Signal Level Meter, CATV analyzer, spectrum analyzer has been recognized by peers and experts, here is unknown above.