Sensors for automation
In industry collecting data is important. Sensors are the nerve endings of the smart industry. Sensors collect all info in industry. At the same time, with the rapid development of the internet Industry 4.0, and intelligent manufacturing, application requirements are getting higher and higher. Smart sensors that collect the most initial data are rapidly upgrading and iterating, driving the intelligent transformation of industrial Internet terminals.
Smart sensors act like human. They monitor, analyze and process data such as motion, temperature, pressure, …etc. it depends on the type of sensors. Sensors should be easy to access and low cost.
Type of industrial sensors
Criteria for selection
various sensors make an industrial control system. They connect to the main controller via an interface module. This module has a signal conditioning component, and an Analog gain amplifier to amplify the signal strength. Analog sensor interfaces generate continuous output signals ranging from a few micro-volts (uV) to several milli-volts (mV), proportional to the quantity being measured. An analog-to-digital (ADC) converter converts the analog signal into a digital format to increase precision and accuracy. The logic controller is the brain of a control system. It receives the sensor signal, processes it as per application requirements, and transmits a control signal via an actuator to the output devices. These include a stepper motor control or conveyor belt motor drive, or any other mechanically operated devices.
In industrial production, temperature is measured heat or frozen parameters. It could collect data from environment or specific conditions. Beside temperature humid is another sensor for collecting data.
The digital temperature sensors are a specific card and has a ten-digit dual-channel successive approximation A/D converter and standard RS-232 or 485. The product adopts a filtering method and average digital software with high full-scale accuracy, strong stability and fast response.
Temperature sensors are used for medical industry, food industry, petrochemical and metallurgy industry.
The pressure sensor is a device that can sense the pressure signals and convert signal into useable electrical signals. Pressure sensors are crucial for monitoring pipelines and leaks. In hydropower and power system pressure sensors are used.
Level sensors are used for monitor, maintain and measure the level of liquids. When the level changed, the sensor sending special signals. Liquid level measure can be divided into continuous or point level measurement. Continuous is used for measure the liquid level. The point level; is used to determine the liquid level in high or low conditions.
This sensor can be used in automobile industry, household appliances such as fridge, washing machine, water tanks.
An infrared sensor is a device that infrared to process data. It also called infrared light sensors. It used for reflection, scattering and absorption. The infrared sensors can have used to control devices such as gas composition analyses and non-destructive testing. Infrared sensors are crucial in some industries such as : medicine, military, space technology, environment.
Proximity sensors are special device to perceive the proximity of an object. It used the sensitive character of displacement sensors. It can be non-contact detection so it will not wear and damage the detection object with no spark or noise. The proximity sensor is different from other detective methods. It is suitable for water, oil enjoinments.
Proximity sensors can detect metal objects in close and without objects. The biggest feature of the variable-range elastic nod device is that it can overload the sensing range of the contact.
Aerospace technology and industrial production such as hotels, restaurants, garages, automatic doors, automatic hot air blowers use proximity sensors, besides, accounting, finance, museums, and vaults are usually equipped with anti-theft devices composed of various proximity switches.
Optical Proximity sensors comprise a light source (LED) and a light detector (phototransistor). The signal is modulated to minimize the ambient lighting conditions. Generally used in box-counting, stack height control, and fluid level control, these sensors work in three operational modes: a) beam mode of 20 m range, b) retro-reflective with a 1-3 meters, and c) diffuse-reflective mode with a 12-300 millimeter range. These sensors are non-contact and insensitive to vibration and shock. They have zero moving parts.
Ultrasonic proximity sensors use a 40 kHz-2MHz frequency range sound pulse to measure the time of flight and amplitude. They are employed as an approach warning before probable collisions and detect solid and liquid levels. As shown in the following figure 3, these sensors detect objects where the normal photocells cannot be employed for level measurement of solids and liquids, diameter or loop detection for materials like sheet iron, paper, and transparent objects detection like plastic, plastic filters, and glass bottles etc.
In conclusion, Proximity sensors have a wide range of uses in a plant setting. Inductive proximity sensors can detect nearby metal, allowing human-machine interfaces (HMI) to remain safer. Laser ranging sensors are another prominent example of proximity sensors in a modern plant environment. A 1D topology laser can be used for object detection on a conveyor line as an infrared motion sensor, while a 2D lidar sensor can be used to identify the positioning of various parts in the production line.
The smoke sensors can detect a large amount of smoke during fire and send out alarm signals. The detector adopts MCU control, which can intelligently judge the smoke generated during the fire and alarm. This sensor is important in a flammable and explosive industrial enjoinment.
The optical sensor is sensitive object on optical principle. It mainly includes optical sensors and instruments such as general optical measuring instruments, laser interferometers, gratings, encoders, and fiber optics. In the design, it is mainly used to detect whether the target object appears, or to perform various industrial automation motion detection.
MEMS sensor is a new type of sensor manufacturing. It can used in microelectronics and micromachining technology. It has small size, low power consumption, high reliability and suitable for mass production. The MEMS motion sensor is integrated with the ZigBee wireless technology to perform anthropomorphic interactions while working with the machine. The feature size on the order of micrometers allows it to perform functions that cannot be achieved by some traditional mechanical sensors. They have been used in space satellites, launch vehicles, aerospace equipment, aircraft, various vehicles, and special It has been widely used in the fields of medicine and consumer electronics.
Vibration sensors capture data from nearby changes in frequency. They utilize MEMS (micro-electro-mechanical systems) accelerometer elements to measure the frequency of vibration, which in turn provides critical data for fault diagnosis as well as a handful of other vital measurements. Accelerometers, gyroscopes, inertial measurement units (IMU), and e-Compasses all utilize vibration sensors in unique ways.