The YOKOGAWA LR4220E level transmitter is a high-precision industrial process measurement and control equipment launched by Yokogawa Electric. It adopts an advanced automatic zero balance digital servo drive system and has excellent measurement stability and anti-interference ability. This device is designed for complex industrial working conditions and can accurately collect and transmit key process parameters such as liquid level and material level, providing reliable data support for the automation control of production processes. Its compact structural design is suitable for small installation spaces, and the IP67 high protection level ensures long-term stable operation in harsh environments. It is widely used in complex control systems in core industrial fields such as chemical, petroleum, and power.
Product Overview
The YOKOGAWA LR4220E level transmitter is a high-precision industrial process measurement and control equipment launched by Yokogawa Electric. It adopts an advanced automatic zero balance digital servo drive system and has excellent measurement stability and anti-interference ability. This device is designed for complex industrial working conditions and can accurately collect and transmit key process parameters such as liquid level and material level, providing reliable data support for the automation control of production processes. Its compact structural design is suitable for small installation spaces, and the IP67 high protection level ensures long-term stable operation in harsh environments. It is widely used in complex control systems in core industrial fields such as chemical, petroleum, and power.
Core technical parameters
2.1 Measurement of relevant parameters
-Measurement principle: Adopting an automatic zero balance digital servo drive system, high-precision signal acquisition is achieved through a floating input circuit with protection (low sensitivity models without protection), with a measurement cycle of up to 135Hz, ensuring real-time data.
-Measurement range: covering multiple types of input signals, suitable for common industrial measurement needs:
-Direct current voltage (DC V): low sensitivity models with a full range of 10mV~200V; Medium sensitivity model 1mV~200V full range; High sensitivity models with a full range of 0.1mV~200V.
-Thermocouple (TC): Supports various models such as R, S, B, K, E, J, T, N, W, L (DIN), U (DIN), KPV SAU 7 FE, etc., suitable for different temperature measurement scenarios.
-Thermistor (RTD): Supports PT100(1mA)、JPT100(1mA)、PT50(1mA)、JPT50(1mA)、J 263*B、Ni100(1mA)/DIN、Ni100(1mA)/SAMA Wait, cover the regular temperature detection requirements.
-Liquid level measurement range: 0-20 meters, meeting common liquid level monitoring needs such as industrial storage tanks and reaction vessels.
-Measurement accuracy: Excellent accuracy performance under standard environmental conditions (23 ± 2 ℃, 55 ± 10% RH):
-DC voltage: ± (0.05% reading+0.03% range+1.0 μ V) (0.1Hz filter is required for 1mV range).
-Thermocouple: Type B ± (0.05% reading+1 ℃) (400~600 ℃, not guaranteed below 400 ℃); R. S-type ± (0.05% reading+1 ℃) (± 3.7 ℃ below 100 ℃, ± 1.5 ℃ between 100 ℃ and 300 ℃); K. E, T, L, U, J, N types ± (0.05% reading+0.5 ℃) (J type -200~100 ℃± 0.7 ℃).
-Thermal resistance: PT100, JPT100, Ni100 ± (0.05% reading+0.2 ℃); KPV SAU 7 FE ± (0.05% reading+0.5 ℃) (not guaranteed below 4K or above 280K); PT50, J 263 * B ± (0.05% reading+0.3 ℃).
-Liquid level measurement accuracy: ± 0.2%, ensuring the accuracy of process control.
-Reference compensation accuracy: R, S, B type ± 1 ℃; Other models ± 0.5 ℃ (an additional 0.5 ℃ is required when measuring temperatures below -100 ℃).
-Anti interference capability: Common mode rejection ratio 150dB (AC), normal mode rejection ratio 50dB (minimum, 50/60Hz); Pulse noise immunity of ± 1kV (pulse width of 800ns, rise time of 1ns), suitable for industrial strong interference environments.
2.2 Electrical Parameters
-Working voltage: 220V AC/AC, it is necessary to connect to an AC power source of specified voltage, and it is strictly prohibited to connect to non rated voltage power sources.
-Input parameters: Maximum allowable source resistance of 1k Ω (DC voltage, thermocouple); Input bias current of 4nA; input resistance of approximately 1M Ω (DC voltage, thermocouple); The maximum allowable input voltage is 250V DC+AC RMS (between the input terminal and the housing, and between the input channels).
-Output signal: Standard 4-20mA analog signal, which can be directly connected to industrial control systems such as PLC and DCS to achieve long-distance transmission and control of parameters.
-Communication Interface: Equipped with RS485 interface and supporting HART digital communication protocol, it can achieve remote configuration of device parameters, data reading and fault diagnosis, facilitating system integration and intelligent management.
2.3 Environmental and Protection Parameters
-Working temperature: -20 ℃ to+60 ℃, suitable for the temperature variation range of most industrial environments.
-Storage temperature: -30 ℃ to+80 ℃, convenient for equipment transportation and long-term storage.
-Protection level: IP67, with complete dust and short-term water immersion protection capabilities, can work normally in harsh working conditions such as high dust and humidity.
-Environmental humidity: Normal operation allows a humidity of 55 ± 10% RH, avoiding use in extreme humidity environments to prevent equipment failure.
Core functions and product features
3.1 Core Functions
-Multi parameter compatible measurement: It can adapt to various input signals such as DC voltage, thermocouple, thermal resistance, etc., and also supports liquid level parameter measurement, achieving multi use of one machine and reducing system configuration costs.
-Flexible filtering settings: Provides 0.1Hz and 1Hz filtering levels and shutdown options, which can be flexibly adjusted according to on-site interference conditions, balancing measurement accuracy and response speed.
-Zero point and range calibration: Supports zero point free adjustment, can correct converter errors through external input range compensation function, and achieves precise calibration by setting zero point and full-scale voltage.
-Data recording and output: Supports the selection of average value recording or maximum/minimum value recording, with a timeline resolution of 0.05mm, equipped with pen offset compensation function, and can achieve data visualization recording through a disposable felt tip pen.
-Fault self check and alarm: The equipment has a complete self check function, which can monitor the status of power, communication, measurement circuits, etc. in real time. When there is an abnormality, it can output an alarm signal in a timely manner, which is convenient for operation and maintenance personnel to respond quickly.
3.2 Product Features
-High precision and high stability: Advanced sensor technology and intelligent algorithms are adopted, combined with a precise digital servo drive system, effectively reducing temperature drift (zero point: 0.05 μ V/℃+0.01% range/℃; Full range: 0.01% range/℃), ensuring long-term stable operation and reliable data output in complex environments.
-Compact design and easy installation: The body structure is compact and small in size, making it easy to install in small spaces on industrial sites and suitable for different installation scenarios.
-The operation interface is intuitive and easy to use: equipped with a clear display panel and simple operation buttons, users can complete parameter settings, calibration, data reading and other operations without professional knowledge background; Simultaneously supporting remote communication configuration, further enhancing operational convenience.
-Strong environmental adaptability: With an IP67 high protection level and excellent anti-interference ability, it can withstand harsh working conditions such as dust, humidity, vibration, and electromagnetic interference, and is suitable for various harsh industrial environments.
-Convenient system integration: Standard 4-20mA analog signal output combined with RS485+HART digital communication can be seamlessly integrated into existing industrial control systems without the need for additional configuration of adaptation modules, reducing the difficulty of system upgrades and modifications.
Applicable scenarios
YOKOGAWA LR4220E is widely used in complex control systems in multiple industrial fields due to its high precision, high stability, and strong environmental adaptability. Its core application scenarios include:
-Petrochemical industry: suitable for measuring liquid level and temperature parameters of crude oil storage tanks, chemical reaction vessels, distillation towers and other equipment. It can work stably in harsh environments such as high temperature, high pressure, high dust, and strong corrosion, providing data support for precise control of production processes.
-Power industry: used for monitoring the water level of power plant boilers, detecting the liquid level of turbine lubricating oil tanks, monitoring the temperature of generator sets and other key links, ensuring the safe and stable operation of power equipment, and avoiding equipment failures caused by abnormal parameters.
-Water treatment industry: Adapt to the measurement of parameters such as sedimentation tank level, clear water tank level, and chemical storage tank level in sewage treatment plants, to assist in the automation control and efficient operation of the water treatment process.
-Metallurgical industry: Used for temperature monitoring of metallurgical furnaces, liquid level detection of raw material storage tanks, and other scenarios, it can withstand harsh working conditions such as high temperature and vibration, ensuring the continuity and safety of metallurgical production.
-Pharmaceutical industry: suitable for measuring key parameters such as reaction kettle temperature and material liquid level in the drug production process, meeting the strict requirements of the pharmaceutical industry for measurement accuracy and stability, and ensuring drug quality.





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