cover
Contact Name
Toto Supriyono
Contact Email
supriyono.toto@unpas.ac.id
Phone
+6282117829291
Journal Mail Official
prodi.mesin@unpas.ac.id
Editorial Address
Jalan Dr. Setiabudi No. 193
Location
Kota bandung,
Jawa barat
INDONESIA
KOLECER: Scientific Journal of Mechanical Engineering
Published by Universitas Pasundan
ISSN : -     EISSN : 31090745     DOI : https://doi.org/10.23969/ksjme
KOLECER Scientific Journal of Mechanical Engineering is an academic journal published by the Mechanical Engineering Department, Universitas Pasundan, dedicated to disseminating research findings conducted by lecturers, students, and researchers. The published articles are expected to serve as references and contribute to the advancement of science and technology. This journal focuses on the field of Mechanical Engineering, covering the following areas: - Materials and Manufacturing - Mechanical System Design and Development - Thermal and Fluid Engineering KOLECER Scientific Journal of Mechanical Engineering is published twice a year, in March and September. Each issue features a minimum of five articles. Manuscripts may be written in English or proper Indonesian, following the Indonesian Language Standardization (PUEBI).
Articles 13 Documents
Pengaruh variasi kecepatan putaran spindle frais milling terhadap sifat kekasaran alumunium 6061 Firmansyah, Mochammad; Wati, Dian Anisa Rokhmah; Pramitasari, Retno Eka; Wijanarko, Nadia Parwaty
KOLECER Scientific Journal of Mechanical Engineering Vol. 1 No. 2 (2025): September 2025
Publisher : Program Studi Teknik Mesin Fakultas Teknik Universitas Pasundan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23969/ksjme.v1i2.30720

Abstract

This research aims to determine the roughness level of a 6061 aluminium workpiece by varying the spindle rotation speed in the milling machine. The results of this study are data on surface roughness obtained through variations in spindle rotation speed during milling. This research uses experimental research methods. Methods that aim to test the effect of a variable on other variables or test the causal relationship between one variable and other variables. The results of this study are presented as roughness test results. The test results using spindle rotation n_1  = 410 rpm; n_2 = 570 rpm; n_3  = 660 rpm. The lowest roughness value occurs at spindle rotation n_3 = 660 rpm, producing an average roughness value of 0.697 µm. The highest roughness value occurs at a spindle rotation of n_1 = 410 rpm, yielding an average roughness of 2.164 µm. Testing at 660 rpm yields smoother results than at 570 rpm and 410 rpm.
Kalibrasi dan analisis ketidakpastian pengukuran sensor temperatur DHT22 menggunakan termometer digital terkalibrasi sebagai alat referensi Sandia Yudha, Viki; Supriyono, Toto; Ghani M, Januar; Rizky Ferdiansyah, Yusuf; Ramadani; Mardiawan, Fajri; Fatah Al Munawar, Rafli
KOLECER Scientific Journal of Mechanical Engineering Vol. 1 No. 2 (2025): September 2025
Publisher : Program Studi Teknik Mesin Fakultas Teknik Universitas Pasundan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23969/ksjme.v1i2.39427

Abstract

The DHT22 digital temperature sensor is widely used in environmental monitoring, building automation, and Internet of Things (IoT) applications due to its low cost and ease of integration. However, its measurement accuracy and precision are limited by manufacturing variability, environmental conditions, and component ageing, which can lead to systematic errors. Therefore, calibration accompanied by measurement uncertainty analysis is required to ensure reliable temperature data. In this study, a DHT22 temperature sensor was calibrated using a calibrated digital thermometer as a reference instrument through a direct comparison method at several temperature points within the sensor’s operating range. Linear regression was applied to derive a correction equation, while measurement error and Type A and Type B uncertainties were evaluated to determine the combined measurement uncertainty. The results show that, before calibration, the DHT22 sensor exhibited a temperature-dependent bias, with errors exceeding 1 °C at medium to high temperatures. The application of the regression-based correction significantly reduced measurement errors and improved agreement with the reference values, as indicated by a high coefficient of determination (R² = 0.998). The combined measurement uncertainty was found to lie within a moderate accuracy range and to increase with temperature, with dominant contributions from measurement repeatability and reference instrument uncertainty. Consequently, the calibrated DHT22 sensor can be more reliably employed in environmental temperature measurement applications requiring moderate accuracy.
Analisis perpindahan panas dan konversi energi pada sistem air conditioner tipe split Wati, Dian Anisa Rokhmah; Wasono, Jami’ul Adi
KOLECER Scientific Journal of Mechanical Engineering Vol. 1 No. 2 (2025): September 2025
Publisher : Program Studi Teknik Mesin Fakultas Teknik Universitas Pasundan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23969/ksjme.v1i2.39518

Abstract

Split-type air conditioning systems are widely used to meet thermal comfort requirements, particularly in tropical regions. The performance of these systems is strongly influenced by the mechanisms of heat transfer and energy conversion occurring during the refrigeration cycle. This study analysed the heat transfer processes and energy conversion mechanisms in a split-type air conditioning system under actual operating conditions. A descriptive–analytical method with a case study approach was employed, involving direct observation, measurement of operational parameters, and technical interviews. The observed parameters included refrigerant temperature and pressure, as well as the performance of the primary refrigeration components, namely the evaporator, compressor, condenser, and expansion valve. The results indicate that cooling in a split-type air conditioner is achieved by transferring thermal energy from indoor air to the outdoor environment, with the assistance of electrical energy converted into mechanical work by the compressor. Each system component was found to play an interdependent role in determining heat transfer effectiveness and overall energy conversion efficiency. Stable operating conditions of refrigerant pressure and temperature were observed to influence system performance significantly. This study provides a comprehensive understanding of the operational characteristics of split-type air conditioning systems from the perspective of heat transfer and energy conversion. It may serve as a basis for improving energy efficiency and optimising air conditioning system performance.

Page 2 of 2 | Total Record : 13