Thermal Drift Correction#
The term thermal drift describes the fact that the measurement accuracy of blaze cameras is affected by temperature changes. During operation, the illumination unit and sensor of the camera heat up. These temperature increases cause a temperature-dependent drift of the distance measurement. Measurement errors occur even at small changes in temperature and even if the overall temperature is within the allowed temperature range.
Using the Feature#
How It Works#
To demonstrate the influence of temperature, the camera behavior during warm-up was examined to understand how the camera reacts to changes in temperature. Similar behavior can be expected if the temperature changes during operation. During testing, the following setup was used:
- Camera faces a flat, white target at a fixed distance of 1500 mm
- Constant ambient temperature of 22 °C
The following figure shows how the camera gradually heats up, illustrated by the temperatures measured at the sensor board and the illumination board.
The next step was to show how the measurement error is affected by temperature changes. As detailed in the Influencing Factors topic, the camera requires a stable operating temperature to deliver accurate results. Depending on the operation mode and installation of the camera, the time required for reaching a stable operating temperature may vary.
The following figure shows that with thermal drift correction enabled, the measurement error is virtually zero from the start compared to a camera without this correction where the error decreases in line with the gradual warming up of the camera.
The following figure shows the measurement error as a function of the temperature. Without thermal drift correction, the temperature-dependent measurement error is about 2.0 mm/K. With the correction enabled, the error is reduced to less than 0.2 mm/K.
Using Thermal Drift Correction#
The ThermalDriftCorrection parameter is enabled by default. This ensures that your measurement results are accurate from the start and remain so even if the environment temperature changes.