Evaluasi Kinerja Sistem Pengukuran Koefisien Seebeck Menggunakan Termokopel

Adu, Pedro Valentino (2026) Evaluasi Kinerja Sistem Pengukuran Koefisien Seebeck Menggunakan Termokopel. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Material termoelektrik dapat menghasilkan tegangan listrik saat diberikan beda temperatur. Parameter yang digunakan untuk mengetahui kemampuan tersebut adalah koefisien Seebeck. Pengukuran koefisien Seebeck menghadapi beberapa kendala karena tegangan Seebeck berada pada orde mikrovolt hingga milivolt dan mudah dipengaruhi oleh noise, offset, kestabilan temperatur, serta kualitas kontak sensor. Ketidakstabilan sistem dalam membentuk beda temperatur dan kesalahan pembacaan temperatur atau tegangan dapat menyebabkan nilai koefisien Seebeck menyimpang dari nilai sebenarnya. Penelitian ini bertujuan mengevaluasi kinerja sistem akuisisi data menggunakan termokopel dalam membaca temperatur dan tegangan rendah, menilai kemampuan sistem heater dan cooler dalam membentuk beda temperatur, serta menentukan koefisien Seebeck sampel termoelektrik. Metode penelitian mencakup perancangan sistem akuisisi data menggunakan termokopel dan ADS1220, pengujian termokopel pada temperatur tinggi dan rendah, pengujian offset dan validasi pembacaan tegangan pada rentang mikrovolt hingga milivolt, serta pengukuran koefisien Seebeck pada sampel ITO dan MoS2/ITO. Hasil pengujian menunjukkan bahwa termokopel menghasilkan nilai drift sebesar −0,10–0,11 °C/menit dan keterulangan sebesar 0,03–0,41 °C. ADS1220 menghasilkan offset rata-rata sebesar 4,75 µV serta nilai MAE sebesar 8,296 µV pada rentang mikrovolt dan 6,623 µV pada rentang milivolt dalam validasi pembacaan tegangan. Sistem pemanas dan pendingin mampu membentuk beda temperatur sebesar 7,20–32 K dan menghasilkan tegangan Seebeck sebesar 172,75 µV–2,702 mV. Namun, sistem menghasilkan MAE sebesar 13,698 °C pada temperatur pemanas 90 °C dan MAE sebesar 6,29 °C pada sistem pendingin. Regresi linear antara tegangan Seebeck dan beda temperatur pada sampel ITO dan MoS2/ITO menghasilkan nilai R2 masing-masing sebesar 0,9961 dan 0,9923, yang menunjukkan bahwa hubungan perubahan tegangan Seebeck terhadap beda temperatur memiliki tingkat kesesuaian yang tinggi dalam model regresi linear. Nilai koefisien Seebeck terbesar pada sampel ITO sebesar 19,628 µV/K mendekati rentang referensi sebesar 17–20,5 µV/K. Sementara itu, nilai koefisien Seebeck pada sampel MoS2/ITO sebesar 107,570 µV/K masih lebih rendah daripada rentang referensi sebesar 200–250 µV/K pada rentang temperatur pemanas 313–363 K atau 40–90 °C.
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Thermoelectric materials can generate an electric voltage when subjected to a temperature difference. The parameter used to determine this capability is the Seebeck coefficient. Measuring the Seebeck coefficient presents several challenges because the Seebeck voltage is in the microvolt to millivolt range and is easily affected by noise, offset, temperature stability, and sensor contact quality. System instability in creating a temperature difference and errors in temperature or voltage readings can cause the Seebeck coefficient value to deviate from its actual value. This study aims to evaluate the performance of a data acquisition system using thermocouples in reading low temperatures and voltages, assess the ability of the heater and cooler systems to create a temperature difference, and determine the Seebeck coefficient of thermoelectric samples. The research methods included designing a data acquisition system using thermocouples and the ADS1220, testing thermocouples at high and low temperatures, testing the offset and validating voltage readings in the microvolt to millivolt range, and measuring the Seebeck coefficient in ITO and MoS2/ITO samples. The test results show that the thermocouples exhibit a drift value of −0.10–0.11 °C/minute and a repeatability of 0.03–0.41 °C. The ADS1220 produced an average offset of 4.75 µV and a mean absolute error (MAE) of 8.296 µV in the microvolt range and 6.623 µV in the millivolt range during voltage reading validation. The heating and cooling systems were capable of generating a temperature difference of 7.20–32 K and producing a Seebeck voltage of 172.75 µV–2.702 mV. However, the system produced an MAE of 13.698 °C at a heating temperature of 90 °C and an MAE of 6.29 °C in the cooling system. Linear regression between the Seebeck voltage and the temperature difference in the ITO and MoS2/ITO samples yielded R2 values of 0.9961 and 0.9923, respectively, indicating that the relationship between the Seebeck voltage change and the temperature difference exhibits a high degree of fit in the linear regression model. The highest Seebeck coefficient value in the ITO sample, 19.628 µV/K, is close to the reference range of 17–20.5 µV/K. Meanwhile, the Seebeck coefficient value for the MoS2/ITO sample, at 107.570 µV/K, is still lower than the reference range of 200–250 µV/K within the heater temperature range of 313–363 K or 40–90 °C.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Koefisien Seebeck, Termokopel, Termoelektrik, Akurasi Data, Seebeck coefficient, Thermocouple, Thermoelectric, Data Accuracy
Subjects:	Q Science > QC Physics > QC100.5 Measuring instruments (General) Q Science > QC Physics > QC271.8.C3 Calibration Q Science > QC Physics > QC271 Temperature measurements
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Physics > 45201-(S1) Undergraduate Thesis
Depositing User:	Pedro Valentino Adu
Date Deposited:	31 Jul 2026 04:17
Last Modified:	31 Jul 2026 04:17
URI:	http://repository.its.ac.id/id/eprint/140647

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