During the automation of various work processes for the high-quality control of complex mechanisms and units, users have to regularly deal with fixing important parameters. Most often these are temperature fluctuations, the frequency of rotation of the mechanism, the flow rate of gas or other liquid, pressure, current strength. In some industries, experts need to know exactly the information about the position of parts of different parts. In this case, an analog sensor comes to the rescue, which differs from all others in numerous advantages.
Description
Multifunctional analog sensors are widely used in large systems for continuous measurement and regulation of various indicators. The basic principle of operation of such units is that when important parameters change, a corresponding change in the output signal occurs.
An analog sensor is a universal element of measuring, regulating, converting and control equipment. Principle of useThis device is distinguished by its accessibility and simplicity. Incoming analog signals are necessarily converted before reaching the computer.
For high-quality data transmission, the user needs to eliminate specific problems that are caused by electrical resistance. For various reasons, the signal may be subject to noise due to unwanted connections of a resistive, capacitive or inductive nature.
Characteristic
An analog sensor creates a special signal that is fed to the input of the processing device. Most often it is a computer port. Most transducer sensors used in classical control systems generate an analog signal. Most often, specialists use the device to solve the following tasks:
- Movement parameters.
- Magnetic and electrical characteristics.
- Moment, force, pressure.
- Expense.
- Temperature.
- Activity of chemical and biochemical type.
- Tank fill level.
- Concentration (liquid, gas, suspended and dissolved substances).
Connection method
The voltage obtained using an analog sensor is easily converted into the required digital form, which is ideal for input into the controller. For these purposes, manufacturers have provided for the presence of special ADC units. The current digital data in the universal controller is transmittedparallel or serial way. It all depends on the specific switching scheme.
Universal actuators or the computer itself are connected to the analog pressure sensor controller. At the bottom of the device you can see the classic connecting thread, which is suitable for the pipeline. A connector for connecting a communication line with the controller is hidden under a small black cover. Durable annealed copper washers must be used for sealing.
Application
The analog temperature sensor in demand today is actively used in automation systems. The main purpose of such an aggregate is to obtain information about various physical quantities. All data is received in real time. A high-quality conversion of a physical quantity into a powerful electrical signal is used, which is ideal for transmission over existing communication lines to a pre-installed controller. All information received is subject to processing.
Most often, analog sensors are installed at a great distance from the computer, which is why such units are often called field devices. This term can be seen in technical literature. In order to connect the analog sensor correctly, the user must be aware that the unit consists of several main parts. The basic element is the sensor. It is this product that is responsible for converting the measured value into an electrical signal. All further actions are performed by the Wheatstone scheme.
New models
Brand new products are on sale today that work on the basis of the HART protocol. The used analog input of the unit is in great demand. The signal is in the range from 4 to 20 A.
High-speed protocol communication is provided in two main ways. The first option is considered a classic, since only two units can exchange information over a reliable two-wire line. This option is especially relevant when the sensors are initially configured.
In the second case, 14 devices can be connected to a two-wire line at once. The final amount always depends on the parameters of the line and the power of the installed power supply.
Output parameters
This parameter is always carefully studied by specialists. Most often, the dependence of the output voltage is directly proportional to the value tested by the user. For example, the higher the pressure in the pipe, the greater the current at the output of the sensor. In some cases, an inverse connection is used. A large value of the output voltage necessarily corresponds to the minimum indicator of the measured parameters at the output of the sensor. The final result largely depends on the controller used.
It is worth noting that some sensors compare favorably with the presence of switching from direct to inverse signal. The most reliable option is when the output range is in the range from 4 to 20 mA. The resulting noise immunity is quite high. If the lower limitshows 4 mA, then the communication line is not broken. Experts actively use a measuring transducer that is designed to work with voltage levels.
Of course, a sensor alone is not enough. Most often, users need to know the pressure and temperature readings. The number of important points in a large enterprise can reach several dozen. That is why a lot of sensors are also needed.
If the controller was installed in a metal cabinet, it is advisable to connect the shielding braids to the cabinet's ground point. The length of connecting lines can reach several kilometers. For calculation it is better to use specialized formulas.
