<![CDATA[This study aims to design and develop a yarn linear density measurement device based on an Arduino Uno microcontroller integrated with an online database recording system (Google Sheet). Conventional measurement of yarn linear density is still carried out manually using a standard reeling device, which requires a relatively long time and is prone to recording errors. Therefore, this research offers an automated and digitized testing solution. The research method includes the mechanical and electronic design of the measuring device, validation of measurement results against a calibrated standard instrument, and the development of a database system and Android application for recording test results. The tests were conducted on three types of yarns (Ne? 19, Ne? 23, and Ne? 31) with ten repetitions each. The two-way ANOVA results indicated no significant differences between the prototype and the standard instrument (F(1,9) = 0.305; p = 0.594), among the tested yarn types (F(2,18) = 2.061; p = 0.156), and in their interaction (F(2,18) = 1.870; p = 0.183), confirming that the prototype is statistically valid. The database-based tracking system also demonstrated a 100% data transmission success rate with a response time of less than two seconds. This study successfully integrates physical measurement and laboratory digitalization, resulting in a prototype of an IoT-based yarn linear density testing system that can be implemented in modern textile testing laboratories, supporting the transformation toward Textile Industry 4.0. ABSTRAK Penelitian ini bertujuan untuk merancang dan mengembangkan alat ukur densitas linear benang berbasis mikrokontroler Arduino Uno yang terintegrasi dengan sistem pencatatan hasil uji berbasis database daring (Google Sheet). Pengukuran densitas linear benang secara konvensional masih dilakukan secara manual menggunakan alat reeling standar yang membutuhkan waktu relatif lama dan rentan terhadap kesalahan pencatatan. Oleh karena itu, penelitian ini menawarkan solusi berbasis otomasi dan digitalisasi pengujian. Metode pelaksanaan meliputi tahap perancangan mekanik dan elektronik alat ukur, pengujian dan validasi hasil alat terhadap alat standar terkalibrasi, serta pengembangan sistem database dan aplikasi Android untuk pencatatan hasil pengujian. Pengujian dilakukan pada tiga jenis benang (Ne? 19, Ne? 23, dan Ne? 31) dengan sepuluh kali pengulangan masing-masing. Hasil analisis ANOVA dua arah menunjukkan tidak terdapat perbedaan yang signifikan antara alat rancangan dan alat standar (F(1,9) = 0,305; p = 0,594), maupun antarjenis benang yang diuji (F(2,18) = 2,061; p = 0,156), serta tidak ada interaksi signifikan antara keduanya (F(2,18) = 1,870; p = 0,183), sehingga alat dapat dikatakan valid. Sistem tracking berbasis database juga menunjukkan tingkat keberhasilan pengiriman data mencapai 100% dengan waktu respon kurang dari dua detik. Penelitian ini berhasil mewujudkan integrasi antara sistem pengukuran fisik dan digitalisasi laboratorium tekstil, serta menjadi prototipe awal sistem pengujian densitas linear berbasis Internet of Things (IoT) yang dapat diimplementasikan di laboratorium pengujian tekstil modern dan mendukung transformasi menuju industri tekstil 4.0. ]]>
