Metal Applications Pyrometers

Among the benefits of using a metal application pyrometer are:

Non-contact measurement: Metal application pyrometers use non-contact IR technology, which makes them suitable for measuring aggressive and extremely hot metal. They have a very rapid response time and will measure objects accurately without influencing their temperature.

High-temperature range: Metal pyrometers can measure the high temperatures typically encountered in metal production and processing, making them suitable for various applications, including molten steel pouring stream, continuous casting, forging and in-furnace product temperature monitoring.

Process optimisation: Precise in-process temperature measurement using pyrometers allows metal processors and manufacturers to improve efficiency and reduce energy consumption. In-process measurement also allows manufacturers to take swift corrective actions to enhance product quality. Each of these benefits can result in increased profitability.

Compliance: Achieving the correct temperature profile when heat treating or processing steel is critical to obtaining the desired metallurgical properties to ensure it has the correct strength, hardness, ductility or malleability for the intended design purpose. Using calibrated IR pyrometers ensures that the metal temperature is accurately measured to recognised traceable standards.

Accuracy: IR pyrometers provide an accurate and fast response to rapidly changing temperatures. This is essential in many manufacturing processes where the material is moving or has a rapidly changing temperature profile, such as in many induction heating processes.

Pyrometers are used extensively in the metals industry and have found multiple applications in all areas of production. Some common application use cases include:

• Monitoring the real-time temperature of the metal object as it is heated in all types of furnaces.
• Measuring the temperature of steel pouring streams to ensure the correct metallurgical properties of the cast steel ingots.
• Ensuring consistent heating and cooling of metals in heat treatment and annealing processes.
• Preventing over or underheating during welding to ensure proper fusion and the integrity of the welded joint.
• Monitoring the temperature of metal when tempering to ensure correct heat treatment.
• Ensuring that the metal is at the correct temperature to achieve the desired shape and properties of metal products in forging operations.
•  Precise measurement of metal object temperatures in vacuum furnaces.
• Continuous measurement of metal objects during the induction heating process.

The consequences of inadequate metal temperature control can be devastating as it will directly affect the metallurgical properties of the material. This can lead to material that is unfit for the intended purpose; for example, it might not have the correct mechanical properties and lead to component failure. Inconsistent or poor product quality can increase manufacturing costs and lead to customer dissatisfaction and reputational damage.

Metal temperature is commonly measured using a non-contact IR pyrometer, an optical device that measures the thermal radiation emitted by a metal surface without direct contact. It uses the radiation to calculate the temperature of the material.

A pyrometer measures the amount of IR radiation emitted by an object and uses optics to focus the radiation onto a sensor; this is converted into an electrical signal processed by the pyrometer electronics to calculate the object’s temperature.

Pyrometers are factory calibrated using a blackbody calibration source, which is a traceable temperature source. Each pyrometer will be shipped with a calibration certificate showing the accuracy of the pyrometer.

To measure a metal surface, the emissivity selected on the pyrometer must match the emissivity of the metal measured. Once done, the pyrometer will accurately measure the material without any further configuration. The pyrometer outputs the metal object’s temperature in Celsius (°C).