Solution
While the device is fully functional before the warm-up period, it is recommended to wait until it has reached thermal stability. Taking measurements before the warm-up period is complete may result in inaccurate readings and invalidate the published specifications.
In summary, the published specifications are only guaranteed if the warm-up time is observed. However, if you need to quantify the error during this period, there are some recommended approaches to account for temperature drift in measurements taken during the warm-up period.
Recommended approaches:
1. Characterize temperature drift during warm-up and estimate accuracy using the AI absolute accuracy equation
- Continuously read the onboard temperature sensor to monitor how much the internal temperature changes and how long it takes to stabilize.
- Once you’ve measured the temperature change, incorporate the observed delta into the AI Absolute Accuracy Equation from the device datasheet.
- Specifically, update the TempChangeFromLastInternalCal and TempChangeFromLastExternalCal to add in the total temperature delta observed
2. Characterize Measurement Drift with a Known Signal
- Use a calibrator to apply a known input signal and monitor how the measured value changes during warm-up. This provides a direct view of drift and helps validate measurement accuracy.
3. Optional: Use Self-Calibration During Warm-Up
- You may perform self-calibration in NI MAX during warm-up to improve accuracy at that moment. However, it is recommended to repeat self-calibration after the warm-up period to ensure long-term stability.