This script is used to experimently determine the emissivity of a sample at different temperatures, using a radiometric technique, as described in this paper. In summary, emissivity is iteratively adjusted until the temperature reading of the pyrometer matches the temperature measured with a reference sensor, e.g. contact sensor (Pt100) or ratio pyrometer.
The project is developed and maintained by the Model Experiments group at the Leibniz Institute for Crystal Growth (IKZ). If you use this code in your research, please cite our associated publication:
S. Foroushani, A. Wintzer, K. Dadzis, In-situ measurement of emissivity in crystal growth furnaces, International Heat Transfer Conference (IHTC17), Cape Town, South Africa, Paper 545 (2023). Available online here
An externally controllable heating plate, one Pt-sensor, a normal and a ratio pyrometer (depending on the used branch). The sample should have a side hole to the center, about 1 mm blow the surface, for inserting the contact sensor. See here for a list of sample devices.
The following files are used to change the devices and measurement settings:
- settings.txt can be used to specify the temperature setpoints, at which measurements will be made. At each step, the script will then steer the heating plate until the sample has reached the desired temperature, within a given threshold.
- Config.yml entails the connection information and parameters of the various devices.
More details about the script, functions and the user interface can be found here and here.
Based on the measurement setup, namely the reference temperature sensor, one of the following branches must be used:
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exp-T-control_steady is a modification of exp-T-control with the added feature that measurements start after the sample temperature has reached steady state. Exp-T-control was created by Vincent Funke.
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TwoPyros is a rewrite of exp-T-control_steady, with a ratio pyrometer used as the reference sensor, thereby eliminating the need for a contact sensor, making the setup purely optical.
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TwoPyros_with_calib is a variant of TwoPyros where the factor k is automatically determined during the measurements based on comparison with the contact sensor. This can be used for calibration or validation of measurements using TwoPyros.
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OnePyro is a modification TwoPyros where the ratio pyrometer is alternated between the normal and ratio modes, thereby eliminating the need for a second pyrometer.
Results are stored in the data folder. Each measurement generates a plot.png, a data.csv file with all recorded data points and values, and a measurment_data.csv file that contains the average data and standard deviations of each measurement point.
This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 851768).
