Temperature measurement: Accuracy matters

"The accuracy of temperature measurements is vitally important to ensure consistent, high quality and performance of the end product, as well as efficiency of the process and safety at the plant. Temperature is one of the most frequently measured parameters and ensuring accuracy in temperature measurement is essential for a whole spectrum of industries, ranging from glass production to metal through to petrochemical. It is widely accepted that if the temperature is accurate then it not only produces a better quality product, but also extends the lifespan of the asset.

Take, for example, the glass industry. Within the glass-melt furnace there are a variety of temperature measurements to be taken in different locations and it is important to be able to trend these throughout the asset. This temperature 'visualisation' must be carried out to identify any cold spots in the refractory wall, which are indicative of possible air leaks caused by structural issues. 

Innovation through the use of continuous non-contact, infrared imaging technology allows more than 300,000 temperature measurement pixels to produce a real time thermal image of the process. This gives the operator a better understanding and allows enhanced control of the temperatures in the glass melt tank.

Thermal vs visual temperature measurement

There are many advantages to thermal vs. visual imaging and point temperature measurements. Using a permanently installed thermal-imaging camera that actively records all necessary and useful data means that the video can be stopped at any frame and measurements can be taken at the exact same point in the process, so that reversals can be tuned more accurately. 

In addition, the beginning of any structural damage caused by ‘out of the ordinary’ operating range high temperatures can be caught rapidly, this is very important for Port Arches and the Crown. Another example, if a crack is developing in a glass melt tank, it may show up as a cold area where air is being pulled in. Identifying as soon as this event begins, using thermal imaging, allows corrective action to be taken before it develops into something far more serious, avoiding potentially very high repair costs and lost production time.

With the NIR-B Borescope and its 90° wide field of view, it is possible to accurately image the temperature of a large area of the furnace through only a small opening in the wall, giving the operator access to data which would have previously been either time consuming or impossible to collect. 

This allows the operator to focus on specific areas of interest, measure live data points and store the data for future analysis. By monitoring the live video, operators can begin to improve melt-tank efficiency and product quality, resulting in reduced process costs.  

As the latest infrared temperature measurement systems allow real time data to be streamed in time lapse modes, this allows process engineers to visualise the flow of the glass melt batch over the process time. As a result of this, alarms can be set in the control equipment to alert operators and ensure optimum glass quality production. 

Effective temperature measurement can extend the lifespan of an asset in a glass melt tank. Using remote infrared, high accuracy thermal imaging devices to measure, monitor and log refractory temperatures allows information to be transmitted instantly and so trigger alarms if temperature differences occur. Thermal imaging cameras can also be positioned underneath a glass melt tank to detect hot spots early, potentially preventing a break out.

These recent advances in measurement technology are helping industrial plants to make significant improvements, both in quality of output and reduction in downtime. As a result of the latest generation temperature measurement technology plants are therefore able to reduce mean time before failure (MTBF) , lower operating costs and enhance production efficiency.”