Quite often, even in domestic conditions, there is a need to measure direct or alternating current, without damaging the integrity of the electrical circuit. For this purpose, special clamp meters and a device with similar design features for alternating current were invented.
The use of electrical measuring tongs
Current clamps for direct and alternating current are designed to measure current without breaking the circuit. None of the analogues provides such functionality. For example, to measure parameters with a multimeter, it is necessary to break the wire, which is not very convenient and safe.
You can connect current clamps for measuring direct and alternating current to any wire, it does not matter if its surface is insulated or not. During operation, pincers must be laid on a wire or on just one bus. The value of the measured parameter should be displayed on the panel.
Most modern models are equipped with a special locking button that allows you to take readings in hard-to-reach places.
Pliers for measuring current strength have a fairly large list of functions. Used in the following cases:
- Calculation of the amount of electricity consumed by a particular electrical appliance.
- Determining the power of equipment.
- Calculation of the actual network load.
Devices are actively used in various industrial enterprises, power plants, factories, as well as in other industries. In everyday life, they are also often used to determine the power of home appliances.
Current clamp metering methods
Only two methods are used to measure the parameters of the electric current in the circuit. The first is indirect or inductive current measurement, and the second is referred to as direct measurement.
Inductive method
The method is used with the use of current transformers or clamp meters, to which it is possible to additionally connect ammeters. However, it should be borne in mind that they measure only the secondary current of the transformer.
In this case, the clamp meter DC and AC work on the principle of a current transformer. The primary winding is the measured conductor, the secondary is directly the pincers.
The advantages of indirect method:
- safety;
- in comparison with the direct method, the ability to measure large amounts of current;
- the ability to take measurements without breaking the circuit;
- simplicity and mobility of the procedure.
Among the disadvantages of inductive measurement, it is worth highlighting a large error and the inability to determine parameters in hard-to-reach places.
Direct way
Direct measurement is carried out with the help of an ordinary ammeter, it is connected at the point of breaking the electric circuit. The essence of the method is the passage of current directly through the ammeter. Ultimately, the control panel displays the obtained value of the measured parameter.
The advantages of this method include:
- simplicity, ease and convenience of calculations;
- measurement accuracy, which depends on the quality and accuracy class of the device.
The disadvantages include the inability to measure large currents due to technical characteristics. It is also impossible to carry out calculations without breaking in a section of the circuit.
Measurements in electrical installations above 1000 V do not have specific features.Clamp meter allows you to quickly, with high accuracy without much effort to calculate the current parameters in the circuit.
To take measurements, the following manipulations are required:
- Using a special switch, the measured value is set.
- They are bred to the side of the tick and put on the conductor.
- The handle is lowered and the device is closed.
The equipment counts data, after which it can be turned off.
Advantages and disadvantages
The great demand for the tool is due to the advantages:
- Ability to save values in the device’s internal memory.
- The small size of the devices allows you to use them even in hard to reach places.
- The non-contact measurement method allows you to increase the permissible limits up to 10,000 V, which is not possible when the ammeter is connected in series with the circuit.
- Simplicity and safety of measurements even in electrical circuits, where the voltage can reach 10,000 V.
- Clamp measurements can be carried out without breaking the circuit for serial connection of equipment.
Specialists highlight the following disadvantages:
- Low accuracy of measurements: the maximum class is only 2.5.
- The wire must have an exact location relative to the plane of the frame, sometimes, in tight conditions, it is not possible to fulfill this condition.
Universal equipment, which combines the functions of clamp meters and a multimeter, is rapidly gaining popularity. The price of such devices varies over a fairly wide range.
What to consider when choosing
In order for the selected device to perform all the tasks assigned to it, it is necessary to select the correct modification with optimal technical characteristics. When making a purchase, you must adhere to the following rules:
- Equipment should be purchased in specialized stores or from official representatives of manufacturers of current-measuring equipment. If there is not enough experience for independent choice, you can get advice from specialists.
- Before buying, it is important to conduct a test run of the ticks and make sure of the highest possible measurement accuracy.
- When choosing, you should also pay attention to the type of measured current. Equipment designed to measure AC / DC is marked AC / DC, respectively.
- For use in everyday life, it is recommended to give preference to models that additionally calculate the resistance of the circuit, voltage and its “ringing”.
- Before acquiring, you need to decide what quantities to deal with when measuring. Each device has maximum and minimum acceptable values.
- It is worth refraining from buying an expensive device with a large number of additional functions, if it will be necessary exclusively for calculating the current strength.
- It is necessary to analyze the diameters of the tires and wires with which to work. Based on these data, the size of ticks is determined.
- Type of sensor. There are different types of ticks, each of them can measure the current strength in different quantities, for example, mA, A and AC. This should also be considered when buying.
- The material of which the housing is made. To protect a person from possible electric shock, only high-quality materials should be used for manufacturing. It is worth refraining from purchasing models of dubious quality, with an unpleasant odor. If there are gaps in the case, the parts are movable - the assembly leaves much to be desired.
Choosing a specific model, it is important to carefully familiarize yourself with its technical characteristics, as well as make sure that there is accompanying documentation and a warranty card.
