TempCHEKs are highly sensitive shrinkage devices that can be used to measure the heatwork within a kiln by accurate measurement of their shrinkage.
Using TempCHEKs, energy input is measured for the firing process commonly referred to as heatwork, which is the combined impact of temperature and time, not solely temperature.
Ceramic materials are heavily impacted by the length of time at which they are exposed to maximum working temperatures. When the time element is ignored, as in temperature measurement, a significant part of the energy equation is left out.
Since TempCHEKs are made from similar ceramic materials to the material being fired, they react to heatwork in the same way.
Replacement of Traveling Thermocouples
TempTABs do not replace traveling thermocouples, but they are an essential tool in the verification of the firing process. Hence, one may need to run a traveling thermocouple when the TempCHEK records indicate a significant change in heatwork being delivered to the ware.
Figure 1. Traveling thermocouples
Traveling thermocouples are needed to analyze the firing profile of the kiln and must be used to provide the kiln supervisor with the total cooling and heating profile of the kiln.
Using TempCHEKs on a routine basis as part of the quality assurance program will ensure that the kiln is delivering the expected heatwork consistently and uniformly.
Verification of Uniformity of Heatwork Delivery Within Wareload and Consistency
Verifying the firing of a product is an essential part of a comprehensive quality assurance system. Using a device that can validate the uniform and consistent delivery of thermal energy required to mature the product is the key to offering processing feedback essential to system control.
TempCHEKs verify the heatwork delivery without disrupting the firing process. Using TempCHEKs on a routine basis, and recording the results using Orton’s proprietary TempCHEK-Trakker software, offers a convenient record of kiln performance with minimum operator time commitment.
The process is simple and very user friendly. It involves:
- Determining where to place the TempCHEKs
- Developing a numbering scheme to identify each location
- Marking each TempCHEK in pencil marked and placing them in the designated location
- The TempCHEKs are retrieved when the relevant car exits the kiln
- With the K193 Orton desktop gauge stand, fitted with a Mitutoyo digital indicator, each TempCHEK is measured and the measurement is sent to the computer hosting the TempCHEK Trakker software
Figure 2. Tracking of the batch of TempCHEKs
The TempCHEK-Trakker software creates a table with the values, as well as a graphical display of the data. Adding upper and lower control limits provides a “quick look” to determine if any location is outside the expected temperature range.
Since the size of the TempCHEK correlates to the temperature it is also possible to compare size rather than convert to a temperature, since the firing profile has a significant influence on the final size of the TempCHEK. An example graph is shown in Figure 3.
Figure 3. XYZ Brick and tile Kiln 1
Figure 4. TempCHEKs from Orton
Synchronization of Thermal Processing Between Kilns
It is no secret that even two kilns that are built alike rarely operate in the same way; however it is desirable to get a uniform product from all production kilns that are firing the same product.
Irrespective of controller settings there is no guarantee that the heatwork delivery will be equal between two kilns.
Using TempCHEKs in each kiln and comparing results will show if and how much difference there is in the thermal energy being delivered to the product by each kiln. Adjusting the firing profile of the errant kiln will synchronize the heatwork delivery and ensure uniform thermal processing. The same approach can be applied between a laboratory kiln and a production kiln.
By adjusting the laboratory kiln profile to yield the same heatwork as the production kiln laboratory development work will be much more likely to repeat when scaling up to production.
About Orton Ceramic Foundation
The Standard Pyrometric Cone Company was established in 1896 by Dr. Edward Orton Jr., the first Chairman of the Ceramic Engineering Department at The Ohio State University. With creation of the Edward Orton Jr. Ceramic Foundation after his death in 1932, the primary focus became providing products to assist and enhance high temperature processing of ceramics and other materials.
Today Orton provides Pyrometric Devices, Thermoanalytical Instruments, and Material Testing to more than 70 countries worldwide.
This information has been sourced, reviewed and adapted from materials provided by Orton Ceramic Foundation.
For more information on this source, please visit Orton Ceramic Foundation.