VERIFIKASI ALAT UKUR SMK Negeri 13 Bandung

Introduction Laboratory is one of facilities in an institution. Laboratory takes parts of research and education. Performance of an institution depend on the performance of it’s laboratories beside human resources. Equipments for analysis especially measurement equipments have big contribution to laboratory performance. Teknologi dan Rekayasa

Laboratoriy Standar ISO 17025 is the international standard which is consist the general requirements of The Competence of Testing and Calibration Laboratories The last version is version 2005. In Indonesia, there is Indonesian versian of ISO/IEC 17025:2005 General Requirements for The Competence of Testing and Calibration Laboratories Teknologi dan Rekayasa

Clausules about Testing and Calibration Laboratories 1. Memiliki fasilitas sumber daya yang cukup untuk melaksanakan pengujian dan atau kalibrasi yang benar 2. Dilengkapi peralatan yang lengkap, terawat dan terkalibrasi 3. Mempunyai personel yang sesuai, terlatih dan memenuhi kualifikasi sesuai lingkup bidang pengujian dan atau kalibrasi 5. Memastikan bahwa kondisi lingkungan dipantau dan dikendalikan seperti yang dipersyaratkan oleh spesifikasi dasar atau metode pengujian dan atau kalibrasi 4. Fasilitas laboratorium untuk pengujian dan atau kalibrasi harus sedemikian rupa dapat memberikan hasil pengujian dan atau kalibrasi yang memadai dan dapat memberikan data yang valid dan benar Teknologi dan Rekayasa

Clausules about Testing and Calibration Laboratories There is a relationship between point 4 and point 5. An equipment or method will have high performance (validity, accuracy) whwn the envionment meet the requirements of calibration. For example : on a volumetric pipette wroten 25mL and 20oC  measurement with volumetric pipette will perform high accuracy at 20oC. In tropical country average temperature is 25oC  calibration is required to check accuracy of measurement Teknologi dan Rekayasa

Calibration for Volumetric Glassware Volume measurement is one of routine tasks in the laboratory Pipettes, burettes, graduated cylinders and volumetric flask are therefore part of basic requirement Though a volumetric pipet may be label 25 mL, it will not deliver exactly that volume For very accurate volumetric analysis, it is advisable to calibrate the volumetric glassware Teknologi dan Rekayasa

Volumetric Equipment are Either Calibrated To Contain (TC) The contained of liquid corresponds exactly to the capacity on the instrument The delivered quantity differs and is reduced by the residue adhering to the wetted glass surface e.g. graduated cylinders and volumetric flasks To Deliver (TD) The delivered quantity of liquid corresponds exactly to the capacity indicated on the instrument The wetting residue remaining has already been taken into account e.g. Pipettes and burettes Teknologi dan Rekayasa

Time to calibrate Calibration result of borrosillicate volumetric glassware will survive all along time except they used to measure the volume of HF, hot H3PO4 , hot alkalis and heated above 150oC in dry condition.  It is recommended to calibrate these equipment after 10 years Soda-lime volumetric equipment will be frosted during application or by hot steam and chemical like HF, hot H3PO4 , hot alkalis and heating above 90oC  It is recommended to calibrate these equipment after 5 years Frosted glassware equipment indicate the alteration in capacity Teknologi dan Rekayasa

3 General Methods to Calibrate Direct, absolute calibration A volume of water delivered or contained by volumetric glassware, is obtained directly from the weight of water and its density Indirect, absolute calibration Volumetric glassware can be calibrated by comparison of the mass of the water it contains or delivers at a particular temperature with that of another vessel which had been calibrated directly Relative Calibration It is often necessary to know only the volumetric relationship between two items of glassware without knowing the absolute volume of either Teknologi dan Rekayasa

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