According to the standard of CQI-9: Special Process, Heat Treatment Assessment, which is compulsorily applied for the automotive industry, to ensure the quality of the product being treated, the performance of furnace shall be monitored periodically according to Temperature Uniformity (TUS) and System Accuracy Test (SAT) methodology. The frequency of TUS shall be at least once a year (annually), except for aluminum parts which required 6 months based, while the SAT normally required quarterly.
Temperature Uniformity Survey (TUS)
The objective of TUS is to validate the temperature uniformity characteristic of the work zone and operating temperature ranges of the furnace or oven. There are two methods for TUS including:
1. Volumetric Method
This method is appropriate for the semi-continuous or batch-type furnace. Since batch-type furnaces almost have the door seal, it is appropriate to apply the volumetric TUS method with the data logger which can be put inside the furnace. It is the best way to save the door seal.
2. Plane Method
It is appropriate for a continuous mesh belt furnace. In order to simulate the actual situation that the product goes through the furnace, the plane method is appropriate for TUS for the continuous furnace
System Accuracy Test (SAT)
The objective of the System Accuracy Test is to ensure the accuracy of the temperature control and monitoring system meet the CQI-9 Requirement at the required frequency. Probe method A is the most convenient one of SAT method to test the thermocouples for monitoring instrument, the controlled instrument as well as recorder.
Picture 8 SAT on site service
Solution After TUS and SAT
Prolific Engineering and Service Co., Ltd. has experience and capability for TUS Service in both methods and SAT. Since the objective of TUS and SAT are to ensure the furnace performance leading to maintain the product quality, not only reporting, the results of TUS and SAT need to be analyzed and advise by our furnace experts for the best solution to improve the furnace performance.
