During the automation of various workflows for the quality management of complex mechanisms and assemblies, 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 a gas or other liquid, pressure, current strength. In some industries, experts need to know exactly where the parts are in different parts. In this case, an analog sensor comes to the rescue, which differs from all the others in numerous advantages.
Description
Multifunctional analog sensors are widely used in large systems of continuous measurement and regulation of various indicators. The basic principle of operation of such units is that when changing important parameters, a corresponding change in the output signal occurs.
An analog sensor is a universal element of measuring, regulating, converting, as well as control equipment. The principle of use of this device is distinguished by its availability and simplicity. The incoming analog signals are necessarily converted before they get into the computer.
For high-quality data transmission to the user, it is necessary to eliminate specific problems that are caused by electrical resistance. For various reasons, the signal may be subject to noise due to unwanted resistive, capacitive, or inductive coupling.
Characteristic
The analog sensor creates a special signal that is fed to the input of the processing device. Most often this is a computer port. Most transducer sensors used in classic control systems generate an analog signal. Most often, specialists use the device to solve the following problems:
- Motion Parameters.
- Magnetic and electrical characteristics.
- Moment, strength, pressure.
- Consumption.
- Temperature.
- The activity of the 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 to the required digital form, which is ideal for input into the controller. For these purposes, manufacturers have provided the availability of special ADC units. Actual digital data in the universal controller is transmitted in parallel or serial manner. It all depends on the specific switching circuit.
Universal actuators or the computer itself are connected to the controller of the analog pressure sensor. At the bottom of the device you can see the classic connecting thread, which is suitable for the pipeline. Under a small black cover is a connector for connecting a communication line with the controller. For sealing it is necessary to use durable washers made of annealed copper.
Application
The analog temperature sensor that is in demand today is actively used in automation systems. The main purpose of such an aggregate is to obtain information about different physical quantities. All data comes in real time. A qualitative 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 the technical literature. In order to properly connect an analog sensor, the user must know 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 circuit.
New models
Today, completely new products that operate on the HART protocol are on sale. 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 classic, since only two units can exchange information on a reliable two-wire line. This option is especially relevant when the initial setup of sensors is performed.
In the second case, 14 devices can be connected to a two-wire line at once. The final amount always depends on the line parameters 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 are favorably distinguished by the presence of switching from direct to inverse signal. The most reliable option is considered when the output range is in the range from 4 to 20 mA. The total noise immunity is quite high. If the lower limit shows 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, you can’t get by with just a sensor. Most often, users need to know the pressure and temperature. The number of important points in a large enterprise can reach several tens. That is why a lot of sensors are also needed.
If the controller was installed in a metal cabinet, it is advisable to connect shielding braids to the cabinet grounding point. The length of the connecting lines can reach several kilometers. For the calculation, it is better to use specialized formulas.