The RLC meter is a radio meter. Its main purpose is to determine the parameters of the total conductivity or impedance of the electrical circuit.
The name "RLC meter" is an abbreviation of the most common system names of those elements whose values are measured by this device. In this case, R means resistance, the letter C is capacitance, and L is inductance.
Operating principle
Professionals who, by their nature of activity, are associated with radio-measuring equipment, need to obtain basic knowledge about how an RLC meter or an immitance meter works. The fact is that these devices are widely used in laboratories, in repair shops and in factories, where with their help they obtain data on the complex conductivity of circuits and their resistance. Very often, the RLC meter is used to test alternating current sources.
What is the operating principle of this precision instrument? It is based on the analysis of the received test signals. Among the main methods that are used to obtain the required parameters, bridge methods are distinguished, as well as those that are associated with the determination of relations according to Ohm's law.
RLC bridge meters work using a measuring bridge, which is balanced by sets of reference reactive (capacitive) and active resistances. Such devices perceive only fixed frequencies.
Meters using Ohm's law relations have simpler schemes of technical self-realization and automated output of measurement results. The principle of their operation is based on the analysis of the passage of a sinusoidal test signal through the measured circuit with a given frequency. In this case, the operating voltage is supplied from the internal generator to the measurement object. It is subject to determination in a selected section of the circuit, where the phase shift and current are simultaneously analyzed. The data obtained are used in the calculation of the necessary parameters.
The main purpose
Currently, there are a wide variety of immitance meters that have different technical characteristics from each other, as well as an indication type, which, in addition to performing their basic functions, can also determine such parameters as:
- phase angle (shift) between voltage and current;
- the performance of the indicator coil;
- the value of the tangent of the loss angle;
- resistance parameter, which is determined on the basis of the obtained data on current strength and voltage;
- some other parameters.
Varieties and specifications
Immitance RLC meters are divided into:
- switch;
- digital;
- combined.
These devices are widely used during research on nanocomposite materials. This is possible due to the fact that changes in the immitance can be easily registered, and its main parameters are very informative. RLC meters have wide functionality and provide high
measurement accuracy, which is within 0.1%. These devices have an operating range from 0.1 to 3 x 10 in the ninth degree of Hz. In addition, they provide measurements of resistance parameters to values of 10 in the eleventh degree of Ohm, capacitance - 750x10 in the third degree of Hz and inductance - 100 F. Moreover, the voltage existing at the measurement object is in the range from 0.003 to 200 V.
In addition to error ranges, the main characteristics of such devices are:
- the frequency range in which the test signal is supplied (the wider it is, the larger the C and L measurements are);
- the presence of external and internal bias by the constant voltage of the test signal (this characteristic is important when measuring the capacitance of varicaps);
- a function that allows such devices to communicate with a personal computer, which is necessary for documenting the obtained measurement results, as well as for their software processing (plotting, indicating the dependence of inductance or capacitance on temperature, etc.);
- the ability to connect a mechanical manipulator to the device, as well as programming the meter for rejecting and sorting the components of the production process.
Modern developments
Today, manufacturers of RLC meters add USB interfaces to the devices they develop, which make it possible to connect to external portable memory blocks or to a computer, and in addition, they constantly improve the technical characteristics of such devices.
For example, the RLC E7-20 meter, manufactured by the Belarusian factory Caliber, operates in the frequency range from 25 to 105 Hertz. Moreover, the error of its measurements does not exceed 0.1%.
The Ukrainian manufacturer Ukrmetrteststandart has developed an immitance meter of the MNS-1100 model. This device is designed to determine the parameters of capacitance and inductance, mutual inductance and resistance, tangents of the angles of phase shift and losses. This RLC
digital meter is used for metrological work, in the process of monitoring radio and electrical products during scientific research, as well as in measuring non-electrical quantities using
measuring transducers.
The device has a wide frequency range from 0.1 to 105 Hz. Moreover, the error of its measurements is only 0.01-0.002%.
Portable appliances
Manufacturers of RLC meters offer small-sized devices that have autonomous (battery) power. These devices have less functionality, weight, dimensions, as well as cost. The error in their measurements is about two percent.
For example, the modern portable RLC meter is offered to be acquired by the American company Agilent Technologies Inc. This manufacturer introduced to the market a new line of hand-held devices that allow specialists and engineers to determine the necessary parameters with maximum speed, accuracy and convenience. This includes the U1733C. U1732C and U1731C. The innovation of these devices is their ability to measure frequencies of up to ten to the fifth power of Hertz, while ensuring a measurement error of only 0.2%. In addition, in the U1730C model of this line, there is a function due to which the automatic identification of components is performed. The result of this work is the display on the screen of the type of device, as well as a detailed analysis of the obtained parameters.
The Belarusian plant "Caliber" released a portable meter E7-18. It operates in a wide range of frequencies, ranging from 20 to 1000 Hz. The measurement error of the model is 0.08%.
Virtual devices
By this variety of devices it is customary to understand devices that are based on a PC. It is the computer that provides the control functions, processing the received data, as well as graphical presentation and information output. To date, such devices are not commercially available. The only such device is a virtual meter created by the Moscow Institute of Control Problems. Trapeznikov Russian Academy of Sciences.
The device has several modifications and is used in a number of universities and research institutes. Its working frequency range is in the range from 10 to 2x10 in the sixth degree of Hz, providing the measurement of complex resistance in the range from ten to minus the third to ten in the ninth degree Ohm. The measurement error in this case is within 0.2%.
Problem Oriented Devices
Omsk LLC “NTTs Transport” produces a digital meter RLC “Immeter”. It allows you to clarify the parameters of the inductance of direct current resistance and quality factor, which exist in the coils of automatic signaling of locomotives, which is also used in subways. In addition, with the help of this device it is possible to clarify the magnitude of the induced EMF, as well as the resistance to current of constant value. The device can measure the parameters of objects at a sinusoidal voltage. In this case, both parallel and sequential two-element equivalent circuitry is possible, which is in the frequency range from 20 to 1000 Hz. The measurement error of such a device is 0.06%.
The Austrian company SY-LAB Gerate GmbH has developed microbiological analyzers of the BacTrac 4250 and 4300 models. Their main purpose is to automatically detect the growth of various microorganisms. Such a device, for example, allows you to ensure control and safety of the quality of the finished product by determining the sterility of solutions and materials.
Recently, the technique of measuring immitance in this area has been widely used due to its versatility and reliability. So, using the BacTrac 4300 instruments, two parameters can be registered. One of them is the medium immitance (M-parameter), and the second is electronic (E-parameter). These two indicators can be taken into account both in combination and separately. Such a measuring system exhibits high sensitivity to microbial metabolites, allowing you to determine the necessary parameters even in nutrient selective media.
RLC E Series
Models of this brand are produced by both domestic and foreign industry. Earlier, back in the days of the USSR, immitance meters of the E7-14 and E7-5 models were widely used. What is known about them?
The values of the main parameters in the amount of 5 instructions of the RLC-meter E7 14 indicates the following:
- operating frequency of 100 Hz, as well as 1 and 10 kHz;
- 0.1 mOhm - 1 GOhm;
- 0.001 pF - 1 F;
- the possibility of self-calibration;
- implementation of microprocessor control.
The weight of this model is 10 kg.
The RLC meter E7 5 gives the following characteristics:
- 1 mOhm - 20 MΩ;
- 0.1 pF - 20 mF;
- the presence of two measurement frequencies - 1 kHz and 100 Hz;
- the ability to control the processor;
- 0.1 mH - 16 kH.
What else can be said about the device? The instructions for the R7 meter E7 5 notes that the weight of this model is 5 kg.
Currently, in connection with the release of new, improved devices, the RLC E-14 and RLC E-5 meters are no longer available. Of this line of devices, specialists most demand meters of later designs with a large number of functions and capabilities.
E7 22 RLC meter
This portable device has a fairly wide range of functionality. Which of them are considered the most valuable? For specialists, the functions that make it possible to carry out tolerance control for various parameters are important.
So, the RLC E7 22 meter:
- It is able to work at a measurement frequency of 1 kHz or 120 Hz, as well as with a serial or parallel equivalent circuit;
- has an automatic selection of limit measurement boundaries and the ability to fix a pre-selected limit;
- has two indicators - to indicate the main and auxiliary parameters;
- has the ability to select indicators and measure the quality factor, loss tangent, and ohmic resistance;
- fixes the maximum, average and minimum values;
- has the function of access control;
- determines the average value from the received data array;
- conducts relative measurements;
- equipped with software compensation for idle and short circuit modes.
The RLC E7-22 meter has some features and functionality that have no analogues among even more complex and expensive RLC devices. It was this moment that made the device very popular for a wide audience. It is used not only by amateurs, but also by professionals working in the field of development of electronic equipment.
In its work, the E7-22 RLC meter uses a variety of measurement frequencies. In this case, the device is able to automatically select the measurement limits. Such a function is used when the necessary parameters are in the widest range, and also when the value of the measured indicator is unknown. It is in such situations that the need arises for the correct choice of the limiting boundaries of measurement. In those devices where manual selection is provided, the study time is significantly increased. However, even when the result is displayed, one cannot be sure of the correct determination of the measurement limit. A consistent enumeration of these boundaries is necessary until it is impossible to verify the reliability of the result. The minimum measurement time will take with the automatic execution of this function.
Another useful feature that the E7-22 RLC meter has is to record the maximum, average, and minimum values. A similar feature is widespread in digital multimeters. In RLC meters, it can be found very rarely. What are the advantages of this device?
The instruction of the RLC E7-22 meter indicates that it is able, after connecting to the circuit, to fix the extreme values of the parameter under study. This function is important for an employee who, for example, exercises control over the quality of manufacturing an entire batch of containers. If the device could not record the maximum and minimum values, a person would have to record the obtained values and conduct their subsequent analysis. The hold function allows the operator not to waste time recording indicators. He only needs to read their extreme values from the indicator in order to compare with the passport data of the party.
What else is convenient for the researcher to measure the RLC E7-22? The instruction contains information on the availability of another interesting function that the device does not have in a similar class. It consists in calculating arithmetic mean values. Being in this mode, the device is able to record up to 3000 measurement results. In such cases, the arithmetic mean values of the indicators appear on the main indicator, and the number of measurements taken on the secondary indicator.
AKIP measuring instruments
This trademark belongs to Prist JSC. This company orders the manufacture of various measuring instruments from manufacturers in America, Asia and Europe . Prior to concluding the contract, the supplier-contractor undergoes a thorough selection, regulatory and technical design and approval process.
Today the AKIP trademark offers its customers RLC meters, signal generators, instruments necessary for measuring energy security indicators, voltmeters and much more.
Which devices are in constant demand among consumers? These are RLC AKIP 6107 meters. They are compact tweezers. With their help, the parameters of passive SMD radio elements are determined. The meters of this model have an ergonomic design, ease of setup and control. Devices allow you to work with them with one hand. At the same time, they are equipped with meters, which significantly reduces the time of troubleshooting and further debugging of the most complex boards.
Another popular model is the RLC P5030 meter. It serves to establish the parameters of resistance, capacitance and inductance, while ensuring the following:
- complete automation of the process of obtaining data;
- tracking mode;
- four-clamp connection of the measurement object;
- mode of obtaining average data.
APPA meters
Devices of this Taiwanese company are also popular with consumers. One of the most popular models is the RLC APPA-701 meter. The device is capable of:
- work day and night, automatically turning on the backlight in low light;
- fully automate the process of obtaining data thanks to the function of selecting the measurement mode;
- connect to a PC using an optically isolated USB port;
- perform internal software calibration.
This ultra-reliable device has an ergonomic case, which is enclosed in a multifunctional protective case with an additional stand. The RLC APPA-701 meter provides autonomous power supply, and therefore it can be used in harsh industrial and field conditions. The device has a shockproof design. It can be dropped onto a concrete floor from a height of 1.3 meters. In this case, the model will not lose any performance.