Calibration/Intermediate Check of Measuring and Volumetric ...

1 Calibration/Intermediate Checkof Measuring and IS calibration ? calibration is the process of comparing a Measuring instrument against a measurement standard to establish the relationship between the values indicated by the instrument and those of the standard (which has traceability to national/ international standard of measurement)2 WHAT IS intermediate Check ? intermediate Check is the process of verifying the calibration status of the Measuring instrument in between is done to verify whether there is any drift in the measurement indicated by the instrument over a period of time3 MANDATORY REQUIREMENTS FOR calibration AS PER NABL 142 -WHEN TRACEABILITY TO SI UNITS IS POSSIBLE calibration OF instruments BY National Physical Laboratory (NPL, India) or any NMI whose service is suitable for the intended need and is covered by the MRA.

2 NABL accredited calibration laboratory or a calibrationlaboratory accredited by an Accreditation Body covered by theILAC Arrangement or by Regional Arrangements recognised byILAC by APLAC, IAAC & EA whose service is suitable forthe intended need ( , the scope of accreditation specificallycovers the appropriate calibration ). BOTH ARE TAKEN AS EVIDENCE OF TRACEABILITY4 MANDATORY REQUIREMENTS FOR calibration AS PER NABL 142 -WHEN TRACEABILITY TO SI UNITS IS NOT POSSIBLE calibration SHALL PROVIDE CONFIDENCE IN MEASUREMENTS BY ESTABLISHING TRACEABILITY TO APPROPRIATE MEASUREMENT STANDARDS SUCH AS Use of Certified Reference Materials provided by acompetent supplier to give a reliable physical orchemical characterization of a material.

3 Use ofmatrix CRM and/or CRM spike Use of specified methods and/or consensusstandards that are clearly described and agreed byall parties concerned. Participation in a suitable programme ofinterlaboratory comparisonsis required where REQUIREMENTS OF calibration Trained & Authorized manpower Documented procedure Suitable Reference standard Multi-point calibration covering working range Estimation of Measurement Uncertainty Acceptable limit in calibration calibration frequency is documented Controlling environmental conditions6 CLASSIFICATION OF EQUIPMENT General service equipment not used for making measurements or with minimal influence on measurements (eg)

4 Hotplates, stirrers, non- Volumetric glassware and glassware used for rough volume measurements such as Measuring cylinders) Volumetric equipment ( flasks, pipettes, pyknometers, burettes etc); Measuring instruments ( hydrometers, U-tube viscometers, thermometers, timers, spectrometers, chromatographs, electrochemical meters, balances etc); Physical standards (weights, reference thermometers); 7 calibration OF GENERAL SERVICE EQUIPMENT Maintained by appropriate cleaning and checks for safety as necessary Calibrations or performance checks will be necessary where the setting can significantly affect the test or analytical result ( temperature of a muffle furnace or constant temperature bath)8 For the highest accuracy, measurements can often be made bymass depending on properly calibrated weighing mechanismwith traceability to accredited calibration laboratories(inINDIA or abroad APLAC/EA Member Countries)

5 Rather than byvolume GRAVIMETRIC METHOD GRAVIMETRIC METHOD consists on weighing the volumetricapparatus under calibration when empty and again when procedure adopted the use of the reference line or marksto have the purpose to provide an exact measure of liquidvolume and the draining or drying procedures shall befollowed carefully because they all effect the difference obtained in the weighing measurements givesthe mass of contained or delivered OF Volumetric EQUIPMENT 9 Balance of suitable capacity and resolution is required as per NABL 122-04 For volume in range of 100 l to 10ml, mg is required For volume in range of 10 ml to 1000ml, 1 mg is required For volume in range of 1000 ml to 2000 ml, 10 mg is requiredCALIBRATION OF Volumetric EQUIPMENT 10 Balance requirement for Micropipette For volume in range of <10 l, mg (Microbalance)

6 For volume in range of 10 l l to 100 l, mg For volume in range of >100 l, mg calibration OF Volumetric EQUIPMENT 11 instruments such as Balance, Hydrometers, Viscometers, Thermometers and Timers should be done by accredited calibration laboratories Other instruments such as pH meter, Conductivity meter, Chromatographs and Spectrophotometers are to be done using valid, reputed/ traceable RMs. Guideline for calibration frequency of REMARKS1 BalanceOnce a year By accredited lab only2 WeightOnce in 2 years By accredited lab only3 Oven, Incubator, FurnaceOnce a year By accredited lab only4 Water BathOnce a year Use suitable reference standard5 Thermometer (Liquid in glass)

7 Once in 3 years By accredited lab onlyCALIBRATION OF Measuring INSTRUMENTS12 calibration OF Measuring REMARKS6 Stop watch / clock Once a yearBy accredited lab only7 HygrometerOnce a yearBy accredited lab only8 Pressure GaugeOnce a yearBy accredited lab only9 Volumetric Labware(Vol. Flask, Burette, Pipette)----In-house; Use suitableBalance10 MicropietteOnce a yearIn-house; Use suitableBalance11 UV-Visible / IR / FT-IR/ Spectrophotometer / Colorimeter QuarterlyPhotometric Absorbance & wavelength accuracy for the working range In-house; Use suitable CRMs13 calibration OF Measuring REMARKS12 Atomic Absorption Spectrophotometer Quarterly/ Half yearlyPerformance Check using Cu CRM as per manufacturer s instruction.

8 13 pH MeterOnce a year In-house; Use suitable CRMs14 Conductivity Meter Once a year In-house; Use suitable CRMs14 calibration OF Measuring REMARKS15 Gas Chromatograph, GC-MS/HPLC / LC-MS Quarterly System performance including: Resolution, sensitivity, repeatability, retention time and noise level Use suitable CRMs/RMs15 calibration OF UV VIS SPECTROPHOTOMETER Use NIST traceable K2Cr2O7for absorbance calibration Use Holmium Oxide Filter or solution with NIST traceability for wavelength calibration If Holmium Oxide Filter is used it has to be calibrated only once in its life time, provided storage conditions are not extreme For stray light calibration use KCl w/v in distilled water.

9 Absorbance should be > OF UV VIS SPECTROPHOTOMETERWAVELENGTH calibration -TOLERANCE ALLOWED : 1 nm in range of 200 400 nm 3 nm in range of > 400 nmABSORBANCE calibration -TOLERANCE to @ 235 to @ 257 to @ 313 to @ 350 to @ 430 nm17 calibration OF Volumetric GLASSWARE AS PER NABL 122 -04 & IS/ISO 4787:2010 and ISO 8655-6 MANDATORY REQUIREMENTS Balance of suitable capacity For volume in range of 100 l to 10ml, mg is required For volume in range of 10 ml to 1000ml, 1 mg is required For volume in range of 1000 ml to 2000 ml, 10 mg is required Reagent Grade Water complying with ISO Grade 3 water Calibrated weights complying with F1 class of weights Air temperature, Relative Humidity and Atmospheric Pressure Monitor Controlled environment as given below.

10 Temperature = (23 + 2) C Relative Humidity = (50 to 85) % Intensity of light above 250 lux18 calibration OF Volumetric GLASSWARE AS PER NABL 122 -04 & IS/ISO 4787:2010 and ISO 8655-6 PRECAUTIONS TO BETAKEN CLEAN GLASSWARE TEMPERATURE STABILIZATION OF GLASSWARE, BALANCE, WATER & WEIGHTS WEIGHING IS DONE USING CONTAINER WITH LID ENSURE WATER IS FREE FROM AIR BUBBLES NO DROPLETS OF WATER ON SIDES OF GLASSWARE NO WETTING OF UPPER AREA OF GLASSWARE 19 calibration OF Volumetric GLASSWARE AS PER NABL 122 -04 & IS/ISO 4787.