Temperature transmitters – find manufacturers and suppliers

Temperature transmitters are devices that receive signals from temperature sensors such as thermocouples or resistance thermometers (RTDs, e.g. Pt100) and convert them into a standardized output signal, e.g. 4-20 mA or 0-10 V.

They are essential components of many industrial applications that require precise temperature measurements and reliable signal transmission. They offer numerous advantages such as increased accuracy, flexibility, easy integration and increased immunity to interference.

Here is an overview of the function, types and areas of application of temperature transmitters and their advantages:

Function and operation of temperature transmitters:

• The main purpose of a temperature transmitter is to receive temperature data from sensors such as thermocouples or resistance thermometers and convert it into a standardized electrical signal. This makes it easier to process and transmit the data over long distances to control systems such as PLCs (programmable logic controllers) or DCSs (distributed control systems).
• Transmitters amplify weak sensor signals and linearize the output so that they can be used directly to obtain precise and reliable measurement data.
• Many temperature transmitters offer galvanic isolation between input, output and supply voltage to prevent measurement errors caused by ground loops or interference.

Types of temperature transmitters:

1. Analog transmitters:
   Output an analog signal (e.g. 4-20 mA), while digital transmitters use digital communication protocols (e.g. HART, Modbus, Profibus).
2. Thermocouple converters:
   These are specifically designed for thermocouples such as type K, J, T, E, N, R, S or B. These converters compensate for the cold junction error (reference temperature compensation) and linearize the non-linear signals of the thermocouples.
3. RTD converters:
   Are suitable for resistance thermometers such as Pt100, Pt1000 etc.. These converters detect the resistance changes in the sensor and convert them into a corresponding output signal.
4. Universal converters:
   Support multiple input signal types (thermocouples, RTDs, resistors and voltage signals) and provide flexibility for various applications.

Areas of application for temperature transmitters:

1. Industrial processes:
In process industries such as chemical, petrochemical, food and beverage, pharmaceutical, metallurgy and papermaking, temperature transmitters are used to monitor and control temperatures in equipment and processes.

2. Heating, ventilation and air conditioning (HVAC) systems:
They are used to monitor and control temperature conditions in buildings, cooling systems and ventilation systems.

3. Energy and power plants:
In power plants and energy generation facilities, temperature transmitters are essential for monitoring steam temperatures, boiler conditions and turbine temperatures.

4. Automation and control:
Temperature transmitters are often used in automated systems to relay data to control systems to enable automatic temperature control.

5. Environmental monitoring:
They are used in environmental data loggers and monitoring systems to measure the ambient temperature in various environments.

Benefits of using temperature transmitters:

• They provide accurate and consistent temperature measurements by converting signals from temperature sensors into standardized output signals that are less susceptible to interference.
• Transmitters can be installed close to the sensor to reduce susceptibility to interference and enable signal transmission over longer distances.
• Standardized signals e.g. 4-20 mA or 0-10 V can be easily integrated into control systems and automation platforms.
• Converters amplify the signal and often provide galvanic isolation to minimize interference and maintain signal quality.
• Using a converter can eliminate the need for expensive special cables, such as thermocouple extension cables, as standardized signals such as 4-20 mA or digital signals can be transmitted over normal, less expensive wires.

Here is an overview of the most important points to consider when buying temperature transmitters:

When purchasing temperature transmitters, several criteria should be considered to ensure that the selected transmitter meets the requirements of the specific applications.

• Make sure that the transducer is compatible with the temperature sensor used. common sensors are thermocouples (e.g. type K, J, T, E, N, R, S, B) or resistance thermometers (RTDs, e.g. Pt100, Pt1000). Some transducers are universal and can support several sensor types.
• The transducer must support the specific signal type and temperature range of the sensor. For example, Pt100 sensors require a transducer that can accurately measure the resistance of the sensor.
• Select the output signal based on the requirements of your control system. Common analog signals are 4-20 mA and 0-10 V. If digital communication is required, the transducer should support protocols such as HART, Modbus or Profibus.
• The output range should match the measurement task and the resolution should be fine enough to ensure the required accuracy.
• Pay attention to the specified accuracy of the transducer. This can be specified as an absolute accuracy (e.g. ±0.1 °C) or as a percentage accuracy (e.g. ±0.1 % of the measuring range). A higher accuracy is particularly necessary in precise applications.
• Check that the transducer offers good long-term stability to ensure that accuracy is maintained over time.
• Galvanically isolated converters are advantageous to avoid ground loops and interference. This feature is particularly important when the transducer is installed in environments with strong electromagnetic fields or with long cable runs.
• The converter must be suitable for the temperature ranges in which it is installed. Pay attention to the specified operating temperature range of the converter.
• Depending on the installation location, a certain degree of protection may be required (e.g. IP65, IP67). This indicates how well the device is protected against dust and moisture.
• If the converter is used in potentially explosive atmospheres, ATEX or IECEx certification is required.
• Pay attention to the mounting options offered by the converter. Common options are DIN rail mounting, enclosures for field mounting or installation in measuring points on site.
• The transducer should be compact enough to fit into the intended mounting position.
• A programmable converter makes it possible to set different input signals and output ranges. This can be done using software tools or DIP switches.
• Some converters offer the possibility to choose between different input types (e.g. RTD, thermocouple, voltage) and output types (e.g. analog, digital).
• If the converter is to be integrated into a digital system, check whether it supports common digital interfaces such as HART, Modbus RTU, Profibus or Ethernet/IP.
• Some converters offer advanced diagnostic functions for detecting faults such as wire breakage, short circuit, sensor error or signal transmission failure. These functions are particularly useful for troubleshooting.
• The converter should be compatible with the existing power supply. Most converters work with 24 V DC, but some models also support other voltages.
• Pay attention to the energy efficiency and power consumption of the converter, especially if many devices are installed.
• Make sure that the converter meets the required international and regional standards, such as CE, UL, CSA, ATEX (for potentially explosive atmospheres) or other industry-specific requirements.
• Check that the converter is supplied calibrated and contains a calibration certificate that is traceable to international standards.
• Some converters have integrated displays that show the measured temperature, sensor status or other information. This can be helpful for on-site commissioning and troubleshooting.
• Some converters offer alarm outputs for signaling errors or limit value violations.
• Check whether the transducer is protected against overvoltage, EMC interference (electromagnetic compatibility) and moisture.
• A cheap converter that does not offer the right accuracy or reliability can be more expensive in the long term.
• Check the manufacturer's warranty and customer support. A good warranty and reliable customer service can be critical in the event of a failure.

When purchasing temperature transmitters, it is important to conduct a thorough evaluation of the specific requirements of your applications and ensure that the selected transmitters meet those requirements. By considering the above criteria, you can select transmitters that will ensure accurate and reliable measurements and provide high performance over the long term.

Temperature transmitters can be sourced from various suppliers. Comprehensive information about manufacturers and suppliers of Temperature transmitters from all over the world can be found on Exportpages.