The EURAMET project 1344, "Comparison of luminous flux using lamps as transfer standards" between LNE-CNAM, France and RCM LIPI, Indonesia was intended to link the RCM LIPI realized lumen to the CCPR key comparison reference values and to demonstrate the RCM LIPI calibration measurement capability in calibrating tungsten standard lamps for transferring this unit. A technical protocol for this comparison was agreed upon by the participants and submitted to the EURAMET and to the CCPR for approval. The comparison was registered on BIPM key comparison data base with the number EURAMET.PR-K4.2.

AbstrakLampu jalan LED memiliki nilai efikasi yang lebih tinggi dibandingkan lampu jalan tradisional. Konsekuensi dari efikasi yang tinggi pada suatu lampu adalah kualitas color rendering yang rendah. Tujuan dari penelitian ini adalah untuk mengukur nilai colorimetrylampu penerangan jalan umum LED. Untuk mengukur kualitas warna dari suatu sumber cahaya digunakan array spectroradiometer. Selain portabilitas dan kecepatan dalam pengukuran spectral, instrument ini memiliki keterbatasan yang harus dikarakterisasi. Salah satunya adalah respon spektral yang memiliki dampak yang cukup besar dalam pengukuran karena itu membutuhkan nilai koreksi dalam penggunaannya. Array spectroradiometer dikalibrasi terhadap lampu spectral irradiant standar untuk pengukuran magnitude dan lampu atomic untuk pengukuran akurasi panjang gelombang. Metode analisis digunakan untuk mengimbangi besarnya pengukuran spectral dari array spectroradiometer yang disebabkan oleh pergeseran spectral. Factor koreksi selanjutnya dikoreksi terhadap beberapa illuminan standard dan digunakan untuk perhitungan rendering index dari lampu jalan LED. Lampu jalan LED dengan nilai efikasi tinggi dapat menghasilkan rendering index pada level 80, tiga kali lebih besar dibandingkan lampu jalan tradisional (HPS) yang hanya mampu menghasilkan rendering index pada level 25. Pada penelitian selanjutnya, dapat dilakukan pengukuran terkait dengan reproduktivitas pengukuran array spektroradiometer yang dapat berdampak pada kualitas pengukuran color rendering. Kata kunci: Color Rendering Index (CRI), lampu penerangan jalan umum LED, array spektroradiometer. AbstractLED Street light considered to have high efficacy compared to traditional street light. However there is a trade of from higher efficacy, which led to poor quality of color rendering. This research aims to measure the colorimetry value of LED street light. Array spectroradiometer commonly used to asses color quality of a light source. Aside from its portability and the speed of spectral measurement, this instruments has limitation that needs to be characterized. One that might have great effect is its spectral response, therefore correction needs to be applied. The array spectroradiometer calibrated against standard spectral irradiance lamp for its magnitude and atomic lamps for its wavelength accuracy. Analytical method applied to compensate the magnitude of spectral measurement of array spectroradiometer due to the spectral shift. The correction factor then validated against several standard illuminant, and applied to calculate rendering index of the LED Street light. With higher efficacy, LED Street light capable to produce rendering index in the level of 80 almost three times larger than traditional street light (HPS) that only can produce rendering index in the level of 25. Future study regarding the measurement reproducibility of an array spectrodiometer is needed, since this problem will affect the measurement quality of color rendering.

Penelitian mengenai efektifitas metode double source dalam pengukuran linearitas detektor optik fotometer standar B310 menggunakan metode double source untuk menggantikan metode invers square law yang menggunakan lampu standar (lampu Wi41/G) sebagai sumber cahaya. Pada metode ini digunakan dua buah lampu Halogen yang memiliki suhu warna dan intensitas yang sama. Pengukuran dilakukan dengan sebelumnya menentukan rentang acuan nilai illuminansi yaitu saat kedua lampu menyala bersamaan. Setelah itu kedua lampu dinyalakan bergantian untuk kemudian dibandingkan dengan rentang acuan. Berdasarkan hasil eksperimen, dengan menggunakan metode double source, diperoleh titik ukur yang lebih banyak dan mencapai hingga nilai illuminansi 4 lux. Faktor linearitas (α) menunjukan nonlinearitas dari detektor optik fotometer standar B310, metode double source efektif pada rentang 20 lux dengan nilai α = 1,0013. Ketidakpastian pengukuran untuk linearitas detektor optik dengan menggunakan double source di setiap rentang lebih kecil dari 0,1%.

Holmium oxide glass filter has known to exhibit persistence absorption lines across the visible region. Due to these properties, a holmium oxide glass filter is used as a reference standard to calibrate the wavelength accuracy of a spectrophotometer. In this research, a system consists of a double-monochromator and a photomultiplier tube will be evaluated. Mathematical modelling is used to calculate the true value of the absorption lines of the holmium glass filter to compensate for the low optical resolution of the double-monochromator system. Measurement results are validated by comparison with the single-monochromator-order shorting filter system which has higher optical resolving power. Wavelength differences between double-monochromator and single-monochromator systems are better than 0.1% and within the expanded uncertainty of 0.32 nm. Therefore, the double-monochromator system is suitable to provide measurement traceability for the calibration of holmium oxide glass filters.

We present an analysis of the illuminance measurement results when a glass neutral density filter (ND Filter) inserted between light source and photometer. ND filters are widely used as an alternative solution in illuminance calibration systems to perform lower illuminance level which caused by inadequate length of the photometric bench. However, there are some variables that must be considered when inserting ND filters in illuminance measurement, one of which is the perceived color temperature of the light source which is influenced by the non-flatness profile of the filter’s spectral. This research was conducted by calculating correction factor for each ND filters, which contribute to illuminance error. Six different ND filters in the range of 1% to 49% are used in this experiment. Scanning the spectral distribution of filter are done to analyzing the change of color temperature of the light source as it passes through an ND filter, due to the lamp must correspond to Illuminant A. This research shows the illuminance measurement error can be up to 20% proportionality to the transmittance as the effect of using ND filters. The results of this study are expected to provide recommendations for the calibration laboratory, especially in illuminance meter calibration.