Liquid or Gas Actuated (Vapor-Tension or Bellows) Industrial Thermometers
Description
Liquid or gas actuated (vapor-tension or bellows) industrial thermometers are devices used to measure temperature. They consist of a small-bore glass tube with a thin-walled glass bulb at the lower end, filled with a liquid or gas such as mercury or alcohol. As the temperature changes, the liquid or gas expands or contracts, causing the column within the tube to rise or fall, which indicates the temperature on a calibrated dial.
Working Principle
These thermometers operate based on the expansion and contraction of a liquid or gas within a sealed system. As the temperature increases, the liquid or gas expands, pushing the column higher up the capillary tube. This movement is translated into a temperature reading on the dial. The gas-filled systems utilize the perfect gas law, maintaining a constant ratio of gas pressure to temperature, which allows for accurate temperature measurement. These thermometers are useful because they provide a simple, direct method of temperature measurement without the need for external power sources.
Applications
Liquid or gas actuated thermometers are commonly used in HVAC applications due to their cost-effectiveness and reliability. They are suitable for environments where precise temperature monitoring is necessary, such as in industrial processes where maintaining specific temperature ranges is critical for product quality and safety.
Advantages over other Manufacturing - Specialized Manufacturing Equipment and Components
These thermometers offer several advantages, including low cost, ease of use, and installation. They are durable and provide accurate readings over a wide range of temperatures. Unlike electronic devices, they do not require power, making them ideal for remote or off-grid applications. Their simple design also makes them less prone to failure compared to more complex electronic systems.
Limitations
One limitation of liquid or gas actuated thermometers is that they are only available as indicating types, meaning they do not provide digital outputs or data logging capabilities. Additionally, their accuracy can be affected by environmental factors, and they may not be as precise as glass stem thermometers. Calibration changes due to use or environmental conditions can also occur, potentially affecting their reliability over time.
Considerations
When selecting a liquid or gas actuated thermometer, it is important to consider the initial cost, which is generally low compared to electronic alternatives. Operating expenses are minimal since they do not require power. However, durability and accuracy can vary based on the materials used in the tube and bulb. Maintenance costs are typically low, but regular calibration checks are recommended to ensure accuracy. Replacement costs are also relatively low, making them a cost-effective choice for many industrial applications.
from KOBOLD Instruments, Inc.
Product Features. Gas-Filled, Capillary Thermometer. Dial Sizes - 63, 80, 100, 160 & 200 mm.. All Stainless Steel Construction. Ranges -40 to 100 °F Through 32 ° to 1100 °F. Available With Up To Four Switches. KOBOLD TNF capillary thermometers are highly versatile and rugged gas-filled... [See More]
- Thermometer Type: Liquid or Gas Actuated (Vapor-Tension)
- Range: -40 to 1100
- Display / Scale Characteristics: Fahrenheit
- Range: 0.0 to 600
from Baumer Ltd.
Mechanical temperature displays still remain today a favorite solution for measuring temperatures right next to the process. They work reliably even if the system loses electrical power and allow a quick check on the process. Baumer supplies mechanical temperature measurement instruments filled with... [See More]
- Thermometer Type: Liquid or Gas Actuated (Vapor-Tension)
- Range: -200 to 800
- Display / Scale Characteristics: Celsius/Centigrade
from Winters Instruments
Versatile, heavy duty gas or vapour thermometer for remote reading applications. [See More]
- Thermometer Type: Liquid or Gas Actuated (Vapor-Tension)
- Range: -40 to 450
- Display / Scale Characteristics: Fahrenheit; Celsius/Centigrade
- Range: -40 to 230
from Watts
Series LFTL Liquid-Fill Angle Lead Free* Thermometers are used in commercial, residential, and institutional HVAC applications. It is a sealed glass tube type model with a polypropylene cases, glass lens, non-mercury bed sensing fluid, and Lead Free* brass thermowells. Accuracy is +/-2 % of full... [See More]
- Thermometer Type: Liquid or Gas Actuated (Vapor-Tension)
- Range: 32 to 932
- Display / Scale Characteristics: Fahrenheit; Celsius/Centigrade
- Range: 0.0 to 500
from KOBOLD Instruments, Inc.
Product Features. Gas-Filled, Rigid Stem Thermometer. Dial Sizes - 63, 80, 100, 160 & 200 mm. All Stainless Steel Wetted Parts. Ranges -40 to 100 °F through 32 ° to 1100 °F. Available With Up To Four Switches. The KOBOLD TNS series rigid stem thermometers are highly versatile and rugged... [See More]
- Thermometer Type: Liquid or Gas Actuated (Vapor-Tension)
- Range: -40 to 1100
- Display / Scale Characteristics: Fahrenheit
- Range: 0.0 to 600
from Watts
Series LFTA Liquid-Fill, Adjustable Angle Lead Free* Thermometers are used in commercial, residential, and institutional HVAC applications. These are sealed glass tube type models with a Valox case, glass lens, non-mercury sensing fluids, and a Lead Free* brass thermowell. Accuracy is +/-1 % of full... [See More]
- Thermometer Type: Liquid or Gas Actuated (Vapor-Tension)
- Range: 0.0 to 120
- Display / Scale Characteristics: Fahrenheit; Celsius/Centigrade