The electrical measuring instrument segment is undergoing a revolution due to the transition to the digital principle of data processing and the trend of combining several functions in one device. At the same time, traditional approaches to the development of this equipment remain in demand. This niche still includes a mechanical ammeter. What it is? This is a device that measures current in its various states. This is not to say that this device does not affect the fashion of the transition to an electronic basis, but mechanical models are still indispensable in many industries.
General information about the device
The ammeter is used in many areas where in one way or another activity is connected with electric current. For example, its function can be used in a car repair shop when repairing electrical wiring, when organizing the work of substations, in construction when performing electrical work, etc.production, there is a need for constant monitoring of technological processes supported by electrical energy. In this case, ammeters are also used. What is it from the point of view of an ordinary user? Is this device necessary for an ordinary consumer? Of course, it is advisable to carry out any electrical operations as part of repair work or when installing a conventional lamp under the control of a measuring device, the main of which in this niche will be an ammeter. Another thing is that in everyday life, simplified versions of the device are used, devoid of many functions used by specialists.
Ammeter device
The design of the device is calculated for serial inclusion in an electrical circuit. To reflect the readings in classic ammeters, a scale with an arrow is used. In order to extend the measurement limits, some models provide the ability to connect to the circuit through a transformer installation or a shunt. The fluctuations of the arrow in the measurement processes are caused by the resistance of the ammeter, which occurs when current passes through the electromagnetic coil built into it. The arrow position angle is proportional to the value of the measured current. Thus, the current strength is fixed, which at the time of measurement acts on the device. Passing through the coil, the current creates a kind of torque on it, the activity of which is reflected in the behavior of the arrow.
Varieties of ammeter
Currently existsseveral versions of the ammeter, each of which has its own design features and some differences in the principle of operation. The most common can be represented as follows:
- Magnetoelectric. The traditional model of the device, reflecting the basic principle of the interaction of a moving coil and a magnetic field. Such devices are characterized by energy efficiency and high sensitivity, which allows them to apply a uniform scale with relatively accurate measurements. The disadvantages of this ammeter are reduced to a complex technical device and limitations in its operation, since it can only be used in direct current conditions.
- Electromagnetic. The design of the device also includes a coil through which the current must pass, and with it the ammeter cores are also used. What is it in terms of operational value? A device with such a filling is quite versatile, since it can operate on both alternating and direct current. Also, its advantages include ergonomic control and compactness. But on the other hand, users note its low sensitivity and unsatisfactory measurement accuracy.
- Electrodynamic. The principle of operation of this device is based on the interaction of magnetic fields passing through two coils - movable and stationary. As a result, during measurements, you can count on the reliability of the readings, but you should also be wary of third-party interference, which, in principle, will make it impossible to operate this device.
Digital ammeter features
Such models are almost devoid of mechanical parts in the filling. Accordingly, the disadvantages of pointer ammeters are also excluded, among which one can name the impossibility of accurate readings in conditions of strong vibrations. Digital devices can be used in both vertical and horizontal positions. Thanks to the electronic basis, the readings themselves can be processed, converted and stored for short-term or long-term statistics in the device's memory. Moreover, the latest generation digital ammeter has also opened up opportunities for automatic operation, in which the device takes readings in specified modes without the participation of an operator.
Use the appliance
The device is introduced into the electrical circuit in series with the load, and in conditions of high current - through a transformer, shunt or magnetic amplifier. Together with an ammeter, calibrated shunts and millivoltmeters can also be used for complex measurement of various current parameters. At a minimum, the combined use of this measurement technique gives more accurate test results. You should also take into account the limitations on measuring the strength of the ammeter, which in conventional models fall within the limits of up to 30-100 A. Beyond these limits, the use of a kiloammeter may be required.
Conclusion
From the point of view of general electrical engineering, the ampere is an elementary unit of measure that is used to reflect the characteristics of various devices and electronicdevices. Differences in the means of measuring this value, rather, are determined by the operating conditions of the ammeter. What is it in the mind of an electrician? Standard tool, which can be made in the form of current clamps. This is not even so much a measuring tool as a mounting fixture for indirect verification of current readings. The situation is quite different with ammeters, which are used in laboratory conditions. In this case, we can talk about stationary equipment with powerful electronics, capable of processing current parameters in conditions of high accuracy, regardless of the source of its origin.
