What is the Relationship Between a Pressure Gauge and a Thermometer

Pressure gauges and thermometers are used in industrial measurement and control systems. Although they measure different physical quantities, one measures pressure, and the other measures temperature. In many industrial processes, they are often used simultaneously to monitor and control the system’s operating status jointly. The basic principles, application scenarios, their interrelationships, and important roles in the industry of pressure gauges and thermometers will be discussed in detail.

What is the Relationship Between a Pressure Gauge and a Thermometer

1. Basic Principles and Applications of Pressure Gauges

1.1 Basic Principles of Pressure Gauges

A pressure gauge is an instrument used to measure the pressure of a fluid (liquid or gas). Common types include mechanical pressure gauges and digital pressure gauges. The Bourdon tube pressure gauge is the most common mechanical pressure gauge that uses elastic components (such as Bourdon tubes, diaphragms, or spring tubes). When the pressure of the measured medium acts on the inside of the Bourdon tube, the Bourdon tube deforms. Drive the pointer to display the pressure value on the plate.

The digital pressure gauge converts the pressure signal into an electrical signal through a pressure sensor and then displays the value through signal processing and a digital module. Pressure sensors usually use pressure strain gauges, piezoelectric, or capacitive elements to sense pressure changes.

1.2. Application of Pressure Gauge

Pressure gauges are widely used in industry, agriculture, medicine, and daily life. The following are some main application scenarios:

  • Industrial process control

In chemical, petroleum, metallurgy, electric power, and other industries, pressure gauges are used to monitor and control the pressure of equipment and pipeline systems to ensure the safety and stability of the production process.

  • Mechanical equipment

In hydraulic systems, pneumatic systems, and lubrication systems, pressure gauges are used to monitor system pressure to prevent over-pressure or loss of pressure and ensure equipment failure.

  • Water supply and gas supply system

In municipal water supply and gas supply systems, pressure gauges are used to measure and regulate the pressure in pipelines to ensure the stability and safety of water supply and gas supply.

  • Medical equipment

In medical equipment, such as ventilators, sphygmomanometers, etc., pressure gauges are used to measure and control the pressure of gas or liquid to ensure patient safety and therapeutic effects.

Stainless steel pressure gauge

2. Basic Principles and Applications of Thermometers

2.1. Basic Principles of Thermometer

A thermometer is an instrument used to measure temperature, and common types include liquid expansion thermometers, bimetal thermometers, thermocouples, and resistance thermometers. Sterilization thermometers work on different principles:

  • Liquid expansion thermometer

Use the properties of the liquid (such as mercury or alcohol) to expand when heated and contract when cooled, and display the temperature through changes in the height of the liquid column.

  • Bimetallic thermometer

It comprises two metal sheets with different expansion coefficients. When the temperature changes, the bimetallic sheet bends, driving the indicator to indicate the temperature.

It is made up of two metal wires of different materials connected. When the temperature of the contact point changes, a thermoelectromotive force is generated, and the temperature is calculated by measuring the thermoelectromotive force.

  • Resistance thermometer

Use the property of the material’s resistance to change with temperature to calculate the temperature by measuring the resistance value.

2.2. Application of Thermometer

Thermometers are widely used in industry, agriculture, scientific research, and daily life. The following are some main application scenarios:

  • Industrial process control

In chemical, metallurgical, petroleum, pharmaceutical, and other industries, thermometers are used to monitor and control the temperature of reactors, distillation towers, boilers, and other equipment to ensure the stability of the production process.

  • Environmental monitoring

Thermometers are used to monitor the atmosphere’s temperature, soil, and water, providing essential data for environmental protection and meteorology.

  • Medical

In the medical field, thermometers are used to measure human body temperature and monitor and treat effects, such as electronic thermometers and infrared forehead thermometers.

  • Food processing and storage

During food processing and storage, thermometers are used to monitor temperature to ensure food safety and quality, such as cold storage thermometers and real-time thermometers.

Bimetallic Thermometer

3. The Relationship Between Pressure Gauge and Thermometer

3.1. Joint Effect on Industrial Process Control

Pressure gauges and thermometers are often used in industrial process control to monitor and control process parameters comprehensively. For example, in chemical production, reactor pressure and temperature are key parameters that must be monitored and controlled simultaneously to ensure the regular progress of chemical reactions and the stability of product quality.

The pressure and temperature of the boiler are two monitoring indicators. The pressure gauge monitors the steam pressure in the boiler to prevent overpressure from causing an explosion. The thermometer monitors the temperature of boiler water and steam to avoid overheating from causing equipment explosion. Damage.

By using pressure gauges and thermometers simultaneously, operators can have a more comprehensive understanding of the operating status of equipment and systems, adjust operating parameters promptly, prevent accidents, and improve production efficiency and safety.

3.2. Data Fusion and Comprehensive Analysis

The pressure and temperature data provided by pressure gauges and thermometers can be fused and comprehensively analyzed, providing an essential reference for system optimization and fault diagnosis. For example, in a hydraulic system, the pressure and temperature of the liquid are closely related. An increase in the liquid’s temperature will cause the liquid’s viscosity to decrease, affecting the system’s pressure. Hydraulic system design and operating parameters can be optimized, and system performance can be improved by monitoring and analyzing pressure and temperature data.

In environmental monitoring, atmospheric pressure and temperature are two critical meteorological parameters. By comprehensively analyzing atmospheric pressure and temperature data, weather changes can be predicted. For example, high temperatures usually bring sunny weather, while low temperatures and low pressures may cause weather or storms.

3.3. Interactive Verification and Auxiliary Diagnosis

Pressure gauges and thermometers can verify each other and assist in diagnosis, improving the accuracy and reliability of measurements. For example, in a steam pipeline system, the pressure and temperature of steam are closely related. By retrieving the steam meter, you can know the pressure. If the barometer and the thermometer readings do not match, it may indicate that one of the instruments is faulty or there is an abnormality in the system.

In automobile engine systems, coolant pressure and temperature are two monitored parameters. Excessively high fluid temperature may cause pressure to rise, affecting the regular operation of the engine. By critically monitoring coolant pressure and temperature, problems can be discovered and dealt with in time to prevent overheating and damage to the engine cooling system.

3.4. Harmony Between Design and Installation

During industrial system design and instrument installation, the selection and layout of pressure gauges and thermometers need to work together. For example, in the design of chemical reactors, the reactor’s working pressure and temperature range are required, and appropriate pressure range and material instruments and thermometers are selected to ensure the durability and accuracy of the instruments.

During the installation process, the position of the pressure gauge and thermometer should pay attention to reading and maintenance while avoiding mutual interference. For example, pressure gauges and thermometers should be installed in areas with low vibration and stable temperatures to prevent the influence of high temperature or sugar environment on the meter readings.

4. Case Studies of Pressure Gauges and Thermometers in Specific Applications

4.1. Chemical Reaction Process

In the chemical reaction process, reaction temperature and pressure are two key parameters directly affecting the reaction speed and product quality. Using a pressure gauge and a thermometer simultaneously, the pressure and temperature in the reactor can be monitored in real-time to ensure the stability of the reaction conditions. For example, the process of synthesizing ammonia needs to be carried out under high temperatures and high-pressure conditions. Ozone and air pressure can be monitored through the pressure gauge. The temperature monitor measures the reaction temperature, optimizes the reaction conditions, and increases the yield of ammonia.

4.2. Boiler System

Steam pressure and temperature are two essential monitoring indicators in the boiler system. The pressure gauge is used to monitor the steam pressure in the boiler to prevent explosion due to overpressure; the thermometer is used to monitor the water and steam temperature in the boiler to prevent equipment damage caused by overheating. By using the pressure gauge and thermometer simultaneously, the operator can adjust the combustion conditions, and an Efficient water supply keeps the boiler system safe and operational.

4.3. Environmental Monitoring

In environmental monitoring, atmospheric pressure and temperature are two critical meteorological parameters. By comprehensively analyzing atmospheric pressure and temperature data, weather changes can be predicted. For example, in a weather station, changes in atmospheric pressure are monitored through pressure gauges, and thermometers monitor daily changes. When combined with other meteorological data, disaster weather conditions can be monitored to provide a reference for agricultural production and disaster prevention.

4.4. Car Cooling System

In automobile cooling systems, coolant pressure and temperature are two monitored parameters. Excessive fluid temperature may cause pressure to rise, affecting regular startup operation. By tracking the coolant pressure with a pressure gauge and the coolant temperature with a thermometer, problems with the cooling system can be discovered and dealt with promptly to prevent engine overheating and damage.

5. Future Development Trends

With the continuous advancement of science and technology, applying pressure gauges and thermometers in industrial measurement and control is also constantly developing. Here are some future trends:

5.1. Standardization

Bright pressure gauges and smart thermometers integrate more sensing technologies and data processing functions, enabling self-diagnosis, automatic adjustment, remote monitoring, and data analysis. For example, an intelligent thermometer can monitor its working status through built-in sensors and send alarm signals when abnormalities occur, improving system reliability and maintenance efficiency.

5.2. Wireless Transmission

Wireless pressure gauges and thermometers use wireless transmission technology to transmit measurement signals to the control center through the wireless network, reducing wiring and maintenance overhead. It has significant advantages in remote monitoring and distributed measurement situations, especially in oil and gas extraction, pipelines, and environmental monitoring.

5.3. Integration

The integrated measurement system integrates pressure, speed, and temperature sensors into one device to achieve multi-parameter synchronous measurement and data fusion processing, improving measurement accuracy and system response. For example, in chemical process control, integrated measurement systems can simultaneously monitor pressure and temperature, optimize process parameters, and improve production efficiency.

5.4. Position and High Stability

With the development of sensing technology and material science, future pressure gauges and thermometers will have higher measurement accuracy and stability. For example, sensors using new piezoelectric materials and microelectromechanical systems (MEMS) technology can maintain high accuracy and stability while working in extreme environments, meeting the needs of aerospace, deep-sea exploration, and high-precision manufacturing.

5.5. Green and Environmentally Friendly

Future pressure gauges and thermometers will pay more attention to green and environmentally friendly design, using materials and energy-saving technologies to reduce their environmental impact. For example, wireless sensors using low-power electronic components and solar power supply technology can achieve long-term, low-power measurements and adapt to environmental requirements.

6. Conclusion

Pressure gauges and thermometers are onboard binary instruments in industrial measurement and control systems. They ensure the safety and stability of the production process by providing accurate pressure and temperature data. Although their working principles and application scenarios differ, they are usually complementary and interdependent. Through reasonable selection, correct installation, and maintenance, pressure gauges and thermometers can be fully utilized to improve measurement accuracy and system reliability. With the continuous advancement of science and technology, future pressure gauges and thermometers will be more automated, integrated, and environmentally friendly, promoting the development of industrial automation and automation.

Scroll to Top