Prior to initiating a critical thermal test, a Test Conductor directs the data acquisition team to perform an end-to-end check on all thermocouple channels. What is the primary purpose of this activity?

1. To verify the entire measurement path from the sensor, through the wiring and signal conditioning, to the data display is functioning correctly.
2. To determine the maximum temperature the data acquisition system can tolerate.
3. To apply the final calibration constants and scaling factors to the raw data.
4. To confirm the structural integrity of the thermocouple mounting points on the test article.