Frequency counter. What is it?
The frequency meter is a measuring instrument that determines the frequency of periodic processes or the harmonic frequency of the spectral signal.
The device design: panel, stationary, portable.
Area of use of the device. All devices are divided into 2 main classes: electrical measuring, radio measuring. It is important to admit that the differences are very insignificant. Electrical measuring group includes analog switch, vibration, electronic counting, and some capacitor devices. The radio-measuring group consists of resonant, heterodyne, capacitor, and some electronic devices.
Counting-type frequency meter
This type of device counts the number of pulses that are formed in the input circuit from an arbitrary, periodic signal in a certain time. Time is given by counting the pulses coming from the quartz oscillator, or from external sources. This kind of device is the most common, as it is universal and has a wide frequency range and high accuracy.
Allows you to compare the frequency of the output signals with their own resonant frequencies. The resonator can serve as oscillatory circuits, waveguide segments (volume resonators). The monitored signal goes through the input circuit to the resonator, then by means of the detector goes to the galvanometer (indicator device). Sometimes, in order to increase the sensitivity of the device, an amplifier is mounted on it. It is designed for tuning, monitoring, maintenance, measuring the frequencies of the modulated signal.
Heterodyne frequency meter
With this device, it is possible to compare the frequency of the input signals and the frequency of the tunable auxiliary generators by means of the zero-beat method. Works like a resonant frequency counter.
Capacitor charge/discharge frequency meter
This kind of device is used to measure frequencies with a wide range (10 hertz – 1 megahertz). Principle of operation: alternating charge of the capacitor from the battery, and then discharge by the magneto electric mechanism. Designed to configure and maintain low-frequency equipment.
Vibration frequency meter
This device is also called reeded, it has a movable part in the form of tongue-plates, which are brought into resonance oscillation under the influence of a magnetic/electric field. It monitors electrical supply networks.
Analog, indicating frequency meter
This kind of device differs by measuring device, and can be electromagnetic, electrodynamic, magnetoelectric. The device is intended for control over electric power networks.
Virtually all frequency meters, especially the old models, produced before the 1990’s, consist of parts containing precious metals: gold, silver, palladium, and platinum in the frequency counter of type C3-44. The largest amount of silver is in the devices Ч3 – 34 A (more than 47 grams), gold in Ч3 – 64: almost 22 grams.