International Journal of Technology (2018) 1: 181-191 ISSN 2086-9614 © IJTech 2018 CALIBRATION PROCESS QUANTITY REDUCTION OF THE THERMAL VOLTAGE CONVERTER STANDARD USING A THREE-STAGE BUILD-UP AND BUILD-DOWN METHOD Hadi Sardjono 1* , Sensus Wijonarko 1 1 Research Centre for Metrology, Indonesian Institute of Sciences, Kompleks Puspiptek Gedung 420, Tangerang Selatan, Banten 15314, Indonesia (Received: April 2017 / Revised: June 2017 / Accepted: January 2018) ABSTRACT Currently, three single junction–type Thermal Voltage Converter (TVC) standard units represent the highest standard of AC (Alternating Current) voltages owned by the Electrical Metrology Laboratory, Research Centre for Metrology—Indonesian Institute of Sciences. The accuracy of the single junction–type TVC is maintained regularly via intercomparison processes using a one-step build-up and build-down method. To reduce the calibration process quantity, three steps of build-up and build-down measurements that refer to the 4 V measurement point of a HOLT production single junction–type TVC were carried out. The dissemination processes with the best measurement accuracy up to 20 ppm were successfully obtained from measurement points between 1 V and 20 V via 4–1V, 4–2V, 4–3V, 4–6V, 4–10V, and 4–20V formations. Keywords: AC voltage quantity; Accuracy; Maintenance; Single junction–type Thermal Voltage Converter (single junction–type TVC) 1. INTRODUCTION The Electrical Metrology Laboratory (EML) maintains its AC (Alternating Current) voltage standards at 1–1000 V using three single junction–type Thermal Voltage Converter (TVC) standard units (Hermach, 1976; Syahadi et al., 2015). The accuracy levels of these standards are maintained via measurement processes based on the intercomparison method. Basically, the ability of the measurement points between 1 V and 1000 V in the 10 Hz to 1 MHz range (Oldham et al., 1997) can be determined by varying operational couples between three single junction–type TVCs and six voltage divider resistances. The single junction–type TVCs have the technical identifications of T2.5-1V (Ballantine), T5-2V (Ballantine), and TE (Holt), while the technical identifications of the six voltage divider resistances are ZVD1, ZVD2, ZVD3, ZVD4, ZVD5, and ZVD6 (Halawa & Al-Rashid, 2010). Pair combinations of the above single junction–type TVCs and voltage divider resistances can produce 15 measurement point capabilities, namely 1 V, 2 V, 3 V, 4 V, 6 V, 10 V, 20 V, 30 V, 60 V, 100 V, 200 V, 300 V, 500 V, 600 V, and 1000 V. Each measuring point must be calibrated to an international standard, such as the Korea Research Institute of Standards and Science (KRISS) standard using the one-step build-up and build-down (OSBUBD) method. OSBUBD has ever been used by Klonz et al. (1995) and Kinard et al. (1997). *Corresponding author’s email: hadisardjono@gmail.com, Tel: +62-21-7560535 (ext. 3092), Fax: +62-21-7560568 Permalink/DOI: https://doi.org/10.14716/ijtech.v9i1.1508