What is CATV meter
TV meter is also named TV signal level meter, field strength meter; For satellite TV it is named satellite finder, satellite locator. 
TV meter is used to evaluate, test the quality of radio and television signals as measuring instrument. This article describes the basic principles of TV meter, key features and commonly used measurements.
TV meter is commonly used in radio and television equipment in broadcasting. It is mainly used in terrestrial television, cable TV, satellite TV signal measurement and analysis. It is always an important job for its systematic evaluation and measurement to radio and television project, but the TV signal strength is the most basic measurement. Through the field strength measurements, we can have a preliminary understanding to the TV system equipment, the quality status of a network operation.
1. Basic concepts of signal level meter .
Signal level meter (field strength meter) is an instrument measuring TV signal strength. Strength stands for electric field strength; it is the level of signal that antenna sensing at one point in space, to characterize the electric field strength at this point. TV signal strength measurement is actually measured by a standard antenna to receive induction territorial television signals, or directly connected to the output of the cable TV signal and read the signal strength with level meter.
Signal level meter makes dB as the unit, such as dBuV, dBmV, dBm.
2. Basic principle of signal level meter
Signal Level Meter is mainly used to test the TV field strength level, generally by the RF input and attenuation circuit, high-frequency tuning circuits, IF demodulation circuits, video processing circuits, spectrum processing circuit, synchronization and display circuit, sound and tone field circuit, power supply and battery charging circuit and other components. The signal level meter is equipped with a CPU, and directly displayed on the screen with a LCD, the operation is very convenient.
3. Function of signal level meter
In addition to the basic level measurement, signal level meter also has other functions, such as sound carrier measurement, carrier noise ratio measurement, TV picture display, audio monitoring, A/V audio video ratio measurement, spectrum measurement, TILT measurement, video output / input, external LNB power supply and so on. Signal Level Meter is generally equipped with a battery, power supply or car charger, easy to carry out for work. Some advanced signal level meter are with spectrum analysis, can make full span scan for the whole frequency range of television signals, or view the spectrum by selected range.
According to their functions, TV meter can be divided into TV signal level meter, TV spectrum signal level meter, CATV analyzer. An advanced TV meter can cover cable television and satellite TV bands, with the function of spectral analysis and color picture display, is capable of the measurement and analysis of both analog TV and digital TV signals.
What is Optical Power Meter
An optical power meter (OPM) is a device used to measure the power in an optical signal. The term usually refers to a device for testing average power in fiber optic systems. Other general purpose light power measuring devices are usually called radiometers, photometers, laser power meters, light meters or lux meters.
A typical optical power meter consists of a calibrated sensor, measuring amplifier and display. The sensor primarily consists of a photodiode selected for the appropriate range of wavelengths and power levels. On the display unit, the measured optical power and set wavelength is displayed. Power meters are calibrated using a traceable calibration standard such as a NIST standard.
A traditional optical power meter responds to a broad spectrum of light, however the calibration is wavelength dependent. This is not normally an issue, since the test wavelength is usually known, however it has a couple of drawbacks. Firstly, the user must set the meter to the correct test wavelength, and secondly if there are other spurious wavelengths present, then wrong readings will result.
Sometimes optical power meters are combined with a different test function such as an Optical Light Source (OLS) or Visual Fault Locator (VFL), or may be a sub-system in a much larger instrument. When combined with a light source, the instrument is usually called an Optical Loss Test Set.
Optical Loss Test Sets (OLTS) are available in dedicated hand held instruments and platform-based modules to suit various network architectures and test requirements. They are used to measure optical power and power loss, and reflectance and reflected power loss. The products may also be used as optical sources or optical power meters, or to measure optical return loss or event reflectance.
Three types of equipment can be used to measure optical power loss:
1. Component equipment - Optical Power Meters (OPMs) and Stabilized Light Sources (SLSs) are packaged separately, but when used together they can provide a measurement of end-to-end optical attenuation over an optical path. Such component equipment can also be used for other measurements.
2. Integrated test set - When an SLS and OPM are packaged in one unit, it is called an integrated test set. Traditionally, an integrated test set is usually called an OLTS. GR-198, Generic Requirements for Hand-Held Stabilized Light Sources, Optical Power Meters, Reflectance Meters, and Optical Loss Test Sets, discusses OLTS equipment in depth.
3. An Optical Time Domain Reflectometer (OTDR) can be used to measure optical link loss if its markers are set at the terminus points for which the fiber loss is desired. The accuracy of such a measurement can be increased if the measurement is made as a bidirectional average of the fiber. GR-196, Generic Requirements for Optical Time Domain Reflectometer (OTDR) Type Equipment, discusses OTDR equipment in depth.