FAQs for TempTAB
Q. How Do TempTABs work?
A. TempTABs are formulated from materials that shrink at a controlled rate over a range of temperatures. The shrinkage has been correlated to firing schedules holding at peak temperature for 10, 30, 60, 120 and 240 minutes.
Q. Will TempTABs survive rapid quenching?
A. Yes. TempTABs will survive high pressure nitrogen or oil quenching. The TempTABs record the peak temperatures in your process.
Q. How sensitive are TempTABs?
A. TempTABs are not intended to be used as a calibration check for thermocouples. When TempTABs are used to conduct heat uniformity surveys they are capable of measuring temperature differences with a sensitivity of +/- 5 °C.
Q. Will TempTABs contaminate the load in my furnace?
A. No. As part of the manufacturing process, TempTABs are pre-treated to remove any organics or other volatile by-products.
Q. Where should I place my TempTABs?
A. TempTABs can be placed anywhere within the load, preferably in the same locations as where temperature uniformity is being verified Regular use will allow you to verify your process and allow you to see trends that may develop over time.
Q. Why do TempTABs have a hole in the middle?
A. TempTABs are designed to be used in a variety of conditions. In applications where they have a chance of changing locations during the process or where they may be exposed to high velocity air (gas) movement, it is recommended that the TempTABs be secured with a wire threaded through the center hole.
Q. Can I check the uniformity of my furnace without wires, bulky thermal protection packages or electronics?
A. Yes. TempTABs allow you to easily verify the temperature uniformity inside your furnace as often as you like.
Q. My Process Runs in an Atmosphere that contains Nitrogen and/or Hydrogen. Will TempTABs work for me?
A. Yes. TempTABs will work in either air or reducing atmospheres.
Q. My process is done in a vacuum. Will they work for me?
A. Yes, They are designed to survive typical vacuum furnaces. TempTABs have been used successfully in vacuum furnaces operating down to 10-6 torr.
Q. How Do I use TempTABs?
A. By comparing the results you can determine the overall uniformity of your furnace. You can easily verify the effect of any changes made to improve the uniformity:
¢ Determine the locations you want to survey.
¢ Place the TempTABs in the locations to be profiled.
¢ Retrieve the TempTABs after they have gone through the furnace.
¢ Measure the TempTABs using the Orton measuring indicator.
¢ Use the lookup table to determine the relative temperatures achieved.
Q. How do I measure the TempTAB?
A. TempTABs are measured after they exit your thermal process. Best accuracy is achieved using the TempTAB Desktop gauge. Place the TempTAB in the gauge and measure the diameter of the part. Measurement can be made using any other means as long as the device reads to .01mm. Enter the measured diameter into the TempTrakker software or look up the temperature from a printed chart.
Q. How do I use the lookup table?
A. TempTABs can be used in a variety of furnaces and conditions. Each batch comes with its own calibrated batch sheet. TempTABs are calibrated for processes with the time in the furnace heating chamber at 10, 30, 60, 120 or 240 minute cycles. Once you have the final dimension of the TempTab, you look for the corresponding temperature in the column that best matches your process. By plotting the relative temperatures of all the TempTABs collected, you can determine the relative temperature uniformity inside the furnace.
Q. Why is Benchmarking important?
A. By benchmarking your furnace's profile during satisfactory operation you establish the basis for comparison any time in the future for trouble shooting or quality assurance. Establishing the baseline is essential for future comparisons. TempTABs are manufactured from blends of various inorganic materials best suited to meet the demands of rapid heating and quenching cycles typical in the metals industry. The material blends and processing are closely controlled to produce a calibrated product from batch to batch. This yields a sensor that can report temperature variations from your baseline as well as variation in temperature distribution uniformity.
Q. How do you recommend I get started using TempTABs?
AFor the benchmarking of your furnaces it is recommended that 10 surveys be conducted at 8-12 hour intervals to insure statistical significance of the data due to natural variations in furnace performance. The information gained from the 10 surveys should profile the natural variation of your furnace and establish an acceptable baseline. Since TempTABs are calibrated to provide the same reading when exposed to like furnace conditions, any subsequent surveys using TempTABs will confirm if the furnace is delivering the same thermal processing as recorded during the benchmarking surveys, or not. To conduct a survey utilizing TempTABs the recommended placement of the TempTABs would be in the same locations you would place thermocouples when conducting a standard heat distribution uniformity survey.
Q. Does it matter how I place the TempTABs in the furnace?
A. No. The TempTAB can be placed flat, on edge or fastened to the basket or fixture with wire through the hole in the center.
Q. What is the significant advantage of TempTABs?
A. The significant advantage of the TempTAB is the frequency at which you can evaluate your thermal process without any interruption of production schedules and with minimal effort. Even though Orton does not recommend using the TempTAB to confirm actual furnace control temperature, any change in the recorded "TempTAB temperature will indicate the actual difference in temperature at any location between the two surveys. Therefore if the TempTAB temperature indicates a significant change in temperature, you can be assured there has been a change in furnace conditions. Of course if the TempTAB indicates no significant change in the recorded temperature, then you can be confident the furnace is operating as it was during the benchmarking run.
Q. Can I use my own calipers to measure the final dimension of the TempTABs?
A. The measurement of the TempTAB is critical for repeatable accuracy. Since the measurement is tangential to the sides of the disk any slight rotation of the disk has the potential to alter the measurement. Orton recommends that the measurements not be made free-hand since it is literally impossible to measure each TempTAB exactly the same every time. Orton has designed a gauge stand that provides consistent placement of the TempTAB for measurement and has this gauge stand with a Mitutoyo digital indicator for sale or Orton will provide you the specifications to build your own gauge stand. Consistent readings to two decimal places in millimeters will provide the accuracy and sensitivity from the TempTAB to support your furnace performance tracking program.
Q. Who benefits from the use of TempTABs?
A. TempTABs offer the furnace operator a unique capability of assessing furnace performance at any time without interrupting production schedules and without the aggravation of thermocouples and all the associated wiring required for a thermocouple array.
TempTABs offer the quality engineer an early warning device to help spot trends before they affect production. They offer an easy way to check furnaces in between formal surveys.
TempTABs offer the maintenance department an easy verification that each furnace is performing as required after every maintenance procedure.
TempTABs offer the person responsible for troubleshooting a quick way to determine if there is a problem with the furnace or if the problem lies somewhere else.
Customers and Company Stakeholders ultimately benefit because improved product quality can translate into lower costs and improved profitability.
Q. Should I keep a log of my furnaces performance?
A. Yes. A table or control chart can be used to build a history of furnace performance over time to establish furnace capabilities and operational competency. The log can be used to confirm quality standards and be available as future reference.
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