Specific Criteria for Calibration Laboratories in Thermal Discipline

Transcription

1 NABL 124 National Accreditation Board for Testing and Calibration Laboratories (NABL) Specific Criteria for Calibration Laboratories in Thermal Discipline ISSUE NO. : 06 AMENDMENT NO. : 00 ISSUE DATE: 19-Dec-2017 AMENDMENT DATE: --

2 AMENDMENT SHEET Sl no 1 Page No. Clause No. Date of Amendment Amendment made Reasons Signature QM Signature CEO Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 1 of 19

3 CONTENTS SI. Contents Page No. Amendment Sheet 1 Contents 2 General Requirements 1. Scope 3 2. Criteria for Accreditation 3 3. Personnel, Qualification and Training 3 4. Accommodation and Environmental Conditions 4 5. Proficiency Testing 5 6. Special Requirements of Laboratory 5 7 Safety Precaution 6 Technical Requirement 8.1 Facility Metrology Requirements Terms & Definitions Selection of Reference standards Selection of Thermal Source Calibration Interval Legal Aspects Environmental Conditions Require for Calibration and 11 Requirement of Environmental Monitoring System 8.9 Calibration Methods Uncertainty of Measurement Reporting of Result Evaluation of CMC Sample Scope Minimum Requirement for Accreditation 19 Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 2 of 19

4 GENERAL REQUIREMENTS: The purpose of this document is to specify requirements with which a laboratory has to operate and demonstrate its competency to carry out calibration in accordance with IS/ISO/IEC 17025:2005. To achieve uniformity between the laboratories, assessors and assessment process in terms of maximum permissible error, CMC, measurement uncertainty etc in line with National/International standards. To achieve uniformity in selection of equipments, calibration methods, maintaining required environmental conditions, personnel with relevant qualification and experience. 1. SCOPE: 1.1. This specific criteria lays down those specific requirements in Thermal discipline. This part of the document thus amplifies the generic requirements for Thermal calibration and supplements the requirements of ISO/IEC 17025: Calibration and Measurement Capability (CMC) is one the parameters that is used by NABL to define the scope of an accredited calibration laboratory, the others being parameter/quantity measured, standard/master used, calibration method used and measurement range. The CMC is expressed as the smallest uncertainty of measurement that a laboratory can achieve when calibrating the best existing device. It is an expanded uncertainty estimated at a confidence level of approximately 95% corresponding to a coverage factor k=2. Note: Refer NABL 143 for NABL policy on Calibration and Measurement Capability (CMC) and uncertainty in calibration. 2. CRITERIA FOR ACCREDITATION Accreditation of a calibration laboratory will require assessment in respect of organization, staff, equipment and traceability of its calibration, laboratory accommodation and environmental conditions, safety, handling of calibrated equipment and equipment under calibration, measurement capability and recording system, etc., as per IS/ISO/ IEC 17025: PERSONNEL, QUALIFICATION AND TRAINING 3.1 Technical Personnel: 3.1.1Qualification Required: a). B.E / B.Tech or equivalent degree, with 3 months experience in Thermal Calibration. b). M.Sc. (Physics / Chemistry) with 3 months experience in Thermal calibration. c). B.Sc (Physics / Chemistry) with 6 month experience in Thermal Calibration. d). Diploma in relevant field with 6 month experience in Thermal Calibration. d). ITI with 1 years of experience in Thermal calibration. Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 3 of 19

5 Training and experience required: a) Training may be external/ internal depending on the expertise available in the field. Effectiveness of training action needs to be ensured. b) Competence of the trainer (internal/external) need to be ensured. c) Training for uncertainty of measurement in Thermal calibration. d) Technical Manager shall have training in Uncertainty of Measurement & CMC evaluation in Thermal Calibration. e) Experience and competence in Thermal calibration. f) Sufficient knowledge about handling of reference equipment, maintenance, traceability, calibration procedure and effect of environmental conditions on the result of calibration. g) During initial training calibration activity should be done under supervision. 3.2 Authorised signatory Qualification required: a) B.E / B.Tech or equivalent degree with 1 year experience in Thermal calibration b) M.Sc. (Physics/Chemistry) with 1 year experience in Thermal calibration. c) B.Sc. (Physics/Chemistry) with 3 year experience in Thermal calibration. d) Diploma in relevant field with 3 year experience in Thermal calibration Training and experience required: a). Training may be external or internal depending on the expertise available in the field b) Training, Experience and Competence in Thermal Calibration and training for uncertainty of measurement. c) Sufficient knowledge and competence in effective implementation of IS/ISO/IEC 17025:2005, NABL specific criteria and guidelines. d) Competency in reviewing of results, giving opinion and interpretations. e) During training the relevant activity has to be done under supervision 4. ACCOMMODATION AND ENVIRONMENTAL CONDITIONS 4.1 Vibration The calibration area shall be adequately free from vibrations generated by central airconditioning plants, vehicular traffic and other sources to ensure consistent and uniform operational conditions. The laboratory shall take all special/ protective precautions like mounting of sensitive apparatus on vibration free tables and pillars etc., isolated from the floor, if necessary. Laboratory to ensure that the magnitude of the vibration should not adversely affect the calibration results. 4.2 Acoustic Noise Acoustic noise level in the laboratory shall be maintained to facilitate proper performance of calibration work. A threshold noise level of 60 dba is recommended unless otherwise stated. Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 4 of 19

6 4.3 Illumination The calibration area shall have adequate level of illumination. Where permissible, fluorescent lighting is preferred to avoid localized heating and temperature drift. The recommended level of illumination is lux on the working table. 4.4 Environmental Conditions and Monitoring The environmental conditions for the activity of the laboratory shall be such as not to adversely affect the required accuracy of measurement. Facilities shall be provided whenever necessary for recording temperature, pressure and humidity values prevailing during calibration. The atmospheric conditions maintained in the laboratory during calibration shall be reported in the calibration report/ certificate. At laboratory: Temperature: (25±3) C Humidity: (50±10) % RH At Site: where measurements are performed outside this specified limit, the laboratory must produce documented evidence that the results have been verified. 5. PROFICIENCY TESTING To give further assurance to the accuracy or Uncertainty of measurements, a laboratory will be required to participate, from time to time, in Proficiency Testing Programmes. The laboratory shall remain prepared to participate in the Proficiency Testing Programme through inter-laboratory, inter-comparison schemes wherever it is technically feasible. (Reference NABL 162, 163 and 164 for further details). ILC for reference instrument is required. 6. SPECIAL REQUIREMENTS OF LABORATORY 6.1 The calibration laboratory shall make arrangements for regulated and uninterrupted power supply of proper rating. The recommended voltage regulation level is 1% or better, and Frequency variation 1Hz or better on the calibration bench. 6.2 Adequate arrangements shall be made by the laboratory so as to ensure temperature gradient not exceeding 1C per hour inside the laboratory in case of power failure. 6.3 The laboratory shall use if necessary, isolation transformers and filters etc. to reduce ground current and effects of mains hum interference. 6.4 Special care shall be taken about the location of magnetic field sources like, transformers, looped wires, ferrous materials etc., in order to reduce magnetic interference in the measurements wherever applicable. 6.5 Adequate screening of the laboratory against electromagnetic interference shall be done if necessary. By-pass filters should also be provided to minimize conducted interference effect on the electronic equipment. Special shielding chambers shall be provided in the laboratory for measurements, particularly when signal to noise ratio is a disturbing factor for accurate measurements. 6.6 Adequate protective measures, like use of transient suppressors etc. shall be taken by the laboratory toward off high current spikes and transients emanating from switching on and off, of the heavy machines, surges in power lines and other such reasons, from reaching the electronics equipment in general and computer based systems involving data storage facilities in particular. Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 5 of 19

7 6.7 The reference standards shall be maintained at temperatures specified for their maintenance on order to ensure their conformance to the required level of operation. 6.8 The laboratory shall take adequate and suitable measure against dust and external air pressure. 6.9 Laboratory using fluids (oil/alcohol used in the calibration bath) may produce noxious or toxic fumes under certain circumstances. Fluid manufacturer s MSDS (Material Safety Data Sheet) may be referred. Exhaust hood of sufficient capacity should be provided to pull oil fumes away from the operator. 7. SAFETY PRECAUTIONS 7.1 Relevant fire extinguishing equipment for possible fire hazards shall be available in the corridors or convenient places in the laboratory. Adequate safety measures against electrical, chemical fire hazards must be available at the work place. Laboratory rooms/ areas where highly inflammable materials are used/ stored shall be identified. Access to the relevant fire equipment shall be assured near these rooms/ areas. 7.2 Specification SP , a special publication in the form of a wall chart, giving the method of treatment in case of electric shock, should be followed. The chart shall be placed near the power supply switchgear and at other prominent places as prescribed under Indian Electricity Rules Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 6 of 19

8 TECHNICAL REQUIREMENTS 8.1 FACILITY Specific Requirements for Thermal calibration with following details:- Sl. No. Description Relevant Standard/ Guidelines Temperature: 1 SPRT, PRT using Fixed Point Cell ITS -90 Permanent facility Onsite calibratio n Mobile facility X X 2. RTD sensors with/without indicator, Temperature Transmitter with/without indicator 3. Thermocouple with/without indicator DKD-R-5-1 ASTM E220-13/EURAMET cg-8 4. Liquid-In-Glass Thermometer, Dial Temperature Gauge IS 6274, IS 2480, OIML R Indicator of Liquid DKD-R5-7 bath, Furnace, Oven, Freezer, Dry block Bath, X Cold Room, Chamber 6. Liquid bath, IEC Furnace, Oven, (Part 3-6), Part Freezer,, Cold 11, DKD-R5-7 Room, X Environmental Chamber 7. Dry block Bath EURAMET cg -13 X 8. Infrared radiation thermometer/ Pyrometer MSL technical guide 22, VDI/VDE 355 Part Black Body Source Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 7 of 19

9 Relative Humidity 1. Humidity Sensor/ Transducer/Trans mitter with Indicator 2. Indicator of Humidity Chamber, Environmental Chamber 3. Humidity Chamber, Environmental Chamber DKD R5-7 DKD-R5-7 X X Note 1:This technical requirement is based on above referred standard taking into account only the salient features required during calibration. Lab may follow any relevant standard; however care shall be taken to follow the requirements in totality. Note 2: larger effective Volume of chamber should not be calibrated for single position value. Only multi position (Mapping) is allowed. Sr.No. Effective Volume of No. of Sensor used Reference standard Chamber l m 3 Minimum 9 IEC >2000 l m 3 Minimum 15 IEC METROLOGICAL REQUIREMENTS Thermocouple without indicator, Cold Junction Compensation to be considered during calibration. IR Thermometer shall be calibrated in the entire range of temperature (Minimum 5 points equally distributed within the range). Lab shall ensure the availability of Triple point of water cell along with realization apparatus for verification of SPRT as a reference 8.3 TERMS & DEFINITIONS Absolute Temperature Temperature measured from absolute zero as in the Kelvin scale. Accuracy Closeness of agreement between a measured quantity value and a true quality value of a measurand (JCGM 200:2012). Ambient Temperature The local temperature of air in the immediate vicinity Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 8 of 19

10 Stability The ability of a measuring instrument to maintain constant metrological characteristics with time Temperature Uniformity The maximum difference of measured temperatures at any sensors and the measured temperature at the reference locations which are observed at the same time or at as close an observation time as possible to determine the temperature pattern or homogeneity within the chamber under steady state conditions. The reference sensor should preferably be located at the geometric center of the chamber. Temperature Stability One-half of the greatest maximum difference of measured temperatures at any one sensor, for at least half an hour after reaching steady state or after one achieved complete cycle of control whichever comes first. The specific check of temperature stability at specific positions or locations of working space within the chamber according to the way of use should be specified. Note: A continuous record of measured temperature is preferable and if not possible, that recorded data should be able to determine the temperature pattern or stability within the chamber under steady state conditions. Overall Variation The difference of the maximum and the minimum measured temperatures throughout observation time. Thermocouple Type K (Chromel / Alumel) - 'general purpose' thermocouple. It is low cost and available in a wide variety of probes. Thermocouples are available in the -200 C to C range. Sensitivity is approx 41uV/ C. Type E (Chromel / Constantan) - non-magnetic and well suited to low temperature (cryogenic) due to its high output (68uV/ C). Type J (Iron / Constantan) - main application is with old equipment that cannot accept 'modern' thermocouples. J has limited range (-40 to +750 C) making it less popular than type K. The J types should not be used above 760 C as an abrupt magnetic transformation will cause permanent decalibration. Type N (Nicrosil / Nisil) - high stability and resistance to high temperature oxidation. Less expensive than platinum (B,R,S) types. Type B (Platinum / Rhodium) - suited for high temperature measurements up to 1800 C. Due to the shape of their temperature / voltage curve they give the same output at 0 C and 42 C. This makes them useless below 50 C. Type R (Platinum / Rhodium) - suited for high temperature measurements up to 1600 C and have low sensitivity 10uV/ C. High cost makes them unsuitable for general purpose use. Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 9 of 19

11 Type S (Platinum / Rhodium) - suited for high temperature measurements up to 1600 C and have low sensitivity 10uV/vC. High cost makes them unsuitable for general purpose use. Due to its high stability type S is used as the standard of calibration for the melting point of gold ( C). 8.4 SELECTION OF REFERENCE STANDARDS RTD Standard should be minimum Class A or better (4 wire) Thermocouple should be of noble metals like R, S and B. For Temperature Mapping base metal thermocouple (preferably N Type) are acceptable (AMS 2750/ API 20H) Certified Humidity salt Solutions, Humidity Chamber for RH probe Calibration. Reference RH probe with indicator for RH Probe calibration. 8.5 SELECTION OF THERMAL SOURCE Fixed point cells along with realization apparatus/ Furnaces for SPRT/HTPRT and PRT. Thermal Equilibrium States or Fixed Points Standard Platinum Resistance Thermometer (SPRT) Liquid Baths (Liquid Nitrogen, Alcohol, Water, Silicon Oil and Molten salt) for Liquidin-Glass Thermometer. Dry Block Calibrators/Bath/Furnace for Sensor calibration Black Body Sources with known emissivity for IR Thermometer. Source shall be owned by the Laboratory. Humidity Generator with Chamber for RH Calibration. 8.6 CALIBRATION INTERVAL Reference Equipment Triple Point of water (Fixed Cells) SPRT,PRT with/without Indicator Thermocouple with/without Indicator Pyrometer Humidity Indicator with Sensor Recommended interval* 1 year 1 year 1 year 1 year 1 year *Recommended calibration interval is having reference to NPL (I) Guideline for calibration frequency 8.7 LEGAL ASPECTS Calibration of Liquid-in-Glass Thermometer done by any accredited laboratories is meant for scientific and industrial purpose only. However, if used for commercial trading, additional recognition/ approval shall be complied as required by Dept. of Legal Metrology, Regulatory Bodies, etc. Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 10 of 19

12 8.8 ENVIRONMENTAL CONDITIONS REQUIRED FOR CALIBRATION AND REQUIREMENT OF ENVIRONMENT MONITORING SYSTEM Environmental conditions Laboratory is advised to follow Manufacturer s recommendation for environmental conditions, operation and maintenance of SPRT, Thermocouple, Temperature Bath, Oven etc Laboratory should be provided with proper arrangement for exhaust of fumes created by oil/ alcohol bath Recommended Environment Monitoring Equipments Temperature with a resolution of 0.1 C Humidity with a resolution of 1% RH Barometer with 1 mbar However, laboratory shall evaluate the requirement of accuracy, resolution and uncertainty depending on the CMC aimed at. 8.9 CALIBRATION METHODS Fixed Point Method This absolute method is used for the realization of the International temperature scale, ITS-90. The thermometer is calibrated by measurements at a series of temperature fixed points: e.g. freezing/melting points, triple points, vapour pressure points. This method consists in setting up a thermometer in a fixed-point cell that provides an isothermal environment. Methods for highly accurate fixed point realizations are described in detail in "Supplementary Information for the ITS-90" [CCT (1990)] Comparison Method A reference thermometer and the thermometer/thermocouple to be calibrated are immersed in a suitable, stirred liquid bath (organic liquid, water, oil or salt) or put in a suitable laboratory furnace, and the readings of the thermometers are compared. The choice of calibration temperatures should cover the range which is used in the temperature measurement. It is important that the sensing head of the thermometer is calibrated and that of the reference thermometer is at the same temperature. Metal blocks which have drilled holes for thermocouples, or other sensing elements, can be used in furnaces for homogenizing the temperature during calibration. If two thermocouples are compared in calibration, it is important to use a stable reference junction temperature. All the Thermal sources shall be studied/known for their stability and uniformity data periodically at least once in a year, in order to use the data to evaluate uncertainty in the measurement. For calibration of relative humidity sensor, the sensor should be placed in the chamber of the humidity generator, the test chamber should be maintained at a stable temperature and measurements are obtained when thermal and water vapor pressure equilibrium conditions Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 11 of 19

13 are reached. For psychrometer calibration, distilled water should be used in the reservoir of the sensor head Non-contact Calibration by Radiation thermometry/pyrometry The laboratories establishing with calibration facilities for Infrared radiation thermometer/pyrometers shall satisfy the following conditions/guidelines. 1. The thermal source used for the calibration should satisfy the condition of blackbody having a known emissivity in order to confirm suitable temperature as measured by standard IR-radiation thermometer. 2. It should be preferred to calibrate a radiation thermometer against a standard radiation thermometer using a blackbody radiation source and not against an ordinary furnace/thermal heating source. Lab may follow any other relevant standard, however care shall be taken to follow the requirements in totality 3. The thermal uniformity and stability shall be measured and evaluated by non-contact technique in order to confirm accuracy in temperature measurement Calibration of thermal sources When calibration of thermal sources (Baths/Furnace/Blackbody source/dry block calibrators) is required to be performed by a laboratory, the following guidelines are strictly to be followed: 1. For calibration procedure some national/international standard should be followed. 2. For the calibration of source, the stability and uniformity are the two major and specific parameters which are really in practice used. 3. Calibration of its set temperature and digital display values shall also be calibrated for effective operation of the source. However, these parameters are not important/ required to be used for practical application of uncertainty evaluation Calibration of Liquid-in-Glass Thermometers: There are specific international and national documentary standards (IS specifications) available for calibration of glass thermometers. These are two different types of liquid-inglass thermometers. One the solid stem and the other enclosed scale stem type of glass thermometers. Similarly according to the practical use, there are further three different categories called as Total Immersion or full immersion thermometers (TI), the Partial Immersion (PI) thermometers and the Complete Immersion (CI) thermometers. 1. Calibration of LIG Thermometers shall not be calibrated on Dry well calibrator sources. 2. Only Temperature liquid baths are employed for glass thermometers. 3. Total Immersion or Partial Immersion thermometers are calibrated as per their condition of immersion only. 4. For calibration of total immersion thermometers, Liquid baths of high depth (~450mm to 500mm) are required. These cannot be calibrated on shallow depth baths. 5. Partial Immersion LIG thermometers are required to be calibrated at specified immersion condition of thermometer stem as marked or mentioned over the stem. Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 12 of 19

14 6. In the calibration of Glass thermometers, readings shall be observed by using a Reading Telescope with suitable magnification (x10 or x20) and not by a magnifying glass. This avoids the parallax error giving faulty reading while reading the thermometer UNCERTAINITY OF MEASUREMENT Sl. Description No. 1 SPRT, PRT using Fixed Point Cell 2. RTD sensors with/without indicator, Temperature Transmitter with/without indicator 3. Thermocouple with/without indicator Uncertainty components Uncertainty in Measurement repeatability Uncertainty of reference standard (s) Drift of reference standard(s) Resolution of readout Uncertainty of resistance measuring unit (Bridge/DVM) Uncertainty due to heating effect Uncertainty due to immersion error Uncertainty due to choice of fixed point (for FP realization) Uncertainty due to purity of fixed point material. Uncertainty due to propagation of error due to TP water. Uncertainty due to atmospheric pressure variation of the cell Uncertainty due to hydrostatic head of the FP cell. Uncertainty in Measurement repeatability Uncertainty of reference standard (s) Uncertainty of readout unit in case of sensor calibration Drift of reference standard(s) Resolution of readout Stability of temperature source Uniformity of temperature source Self-heating error Immersion depth Uncertainty in Measurement repeatability Uncertainty of reference standard (s) Uncertainty of readout unit in case of sensor calibration Drift of reference standard(s) Resolution of readout Stability of temperature source Uniformity of temperature source Stability of ice point for reference junction Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 13 of 19

15 4. Liquid-In-Glass Thermometer, Temperature Gauge Dial 5. Indicator of Liquid bath, Furnace, Oven, Freezer, Dry block Bath, Cold Room, Environmental Chamber 6. Liquid bath, Furnace, Oven, Freezer,, Cold Room, Environmental Chamber 8. Infrared radiation thermometer/ Pyrometer Variation error in the ice point In-homogeneity of thermocouple Uncertainty in Measurement repeatability Uncertainty of reference standard (s) Uncertainty of readout unit in case of sensor calibration Drift of reference standard(s) Resolution of Liquid-In-Glass Thermometer /readout Stability of temperature source Uniformity of temperature source Uncertainty in Measurement repeatability Uncertainty of reference standard (s) Drift of reference standard(s) Temperature Gradient/Temperature Fluctuation Resolution of indicator of source Uncertainty in Measurement repeatability Uncertainty of reference standard (s) Drift of reference standard(s) Temperature Gradient/stability Uniformity of source to be calibrated Resolution of readout wall radiation effect according to various sensor constructions loading effect due to standard and accessories Uncertainty in Measurement repeatability Uncertainty of reference standard pyrometer(s) Drift of reference standard pyrometer (s) Resolution of pyrometer under calibration Stability of temperature radiation source Uniformity of temperature source Uncertainty due to emissivity correction of the source Uncertainty due to size of source effect 9. Black Body Source Uncertainty in Measurement repeatability Uncertainty of reference standard (s) Drift of reference standard(s) Temperature Gradient/stability Uniformity of source to be calibrated Resolution of readout Emissivity variation of the radiation source Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 14 of 19

16 Size of source effect 10. Humidity Sensor/ Transducer/Transmitter with Indicator 11. Indicator of Humidity Chamber, Environmental Chamber 12. Humidity Chamber, Environmental Chamber Uncertainty in Measurement repeatability Uncertainty of reference standard hygrometer(s) Drift of reference standard hygrometer (s) Resolution of readout hygrometer Stability of humidity generator/source Uniformity of humidity generator/source Uncertainty in Measurement repeatability Uncertainty of reference standard hygrometer (s) Drift of reference standard hygrometer Humidity Gradient/Fluctuation Resolution of humidity source Uncertainty in Measurement repeatability Uncertainty of reference standard hygrometer (s) Drift of reference standard hygrometer (s) Temperature Gradient/stability of humidity source Uniformity of source to be calibrated Resolution of indicator of the RH source Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 15 of 19

17 An example of the enclosure calibration and data recording using 9 sensors at a setting of 50 C is shown below: Record No. Chamber Indicator Standard Reading ( C)@ Sensor Number C (Ref) Mean Temporal In stability of each sensor (Max- Min)/ Max : Temporal 2.00 Instability Spatial In uniformity (variation of each average from average of reference sensor) Max: Spatial In 0.50 uniformity from average Values Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 16 of 19

18 8.11 Reporting of Results The calibration certificates issued to the customer shall be in accordance with clause 5.10 of ISO/IEC/17025:2005. Apart from that it shall also include the following: a. Dimensional (Length & Diameter) details of the sensor/ probe used with the digital thermometer. b. Immersion condition of the sensor/probe at which calibration was performed. c. Statement of temperature scale to which measurement refer to, currently the ITS-90 should be mentioned Evaluation of CMC Refer NABL 143 for CMC evaluation CMC value is not the same as expanded uncertainty reported in the calibration Certificate/Report. CMC values exclude the uncertainties which are attributed to the DUC (Device under calibration) Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 17 of 19

19 8.13 Sample Scope An illustrative example for right representation of scope Sl..No 1 Laboratory: XYZ Discipline: Thermal Parameter*/ Device under calibration Temperature For Contact Type Sensor (SPRT S, SSPRT S, PRT S ) $ Master equipment used Using ASL F 600 Bridge & SPRT With Hart Fixed Point TPW cell & Maintenance Apparatus Range(s) of measurement Triple Point of Water (0.01 C) Melting Point of Gallium ( C) Date(s) of Visit: Calibration and Measurement Capability ** Remarks + / Method used Claimed by Laboratory (±) 3.8 m C 6.5 m C Observed by Assessor (±) 3.8 m C 6.5 m C Recommen ded by Assessor (±) 3.8 m C 6.5 m C By comparison By comparison 2 Contact Type Sensor $ ( RTD S, Thermocouple,Temperature Indicators With Sensors) Using Digital Thermometer & SSPRT With Liquid Bath Using Digital Thermometer & R-type Thermocouple With Dry Block calibrator (-) 80 C to 150 C 650 C to 1200 C 0.06 C 1.2 C 0.05 C 1.4 C 0.06 C 1.4 C By comparison By comparison 3 Non Contact Type Infrared Thermometers,Pyrometers $ Using Cropico & PRT with Impac BB 0 C to 250 C 250 C to 1200 C 1.54 C 3.0 C 1.43 C 3.0 C 1.54 C 3.0 C By comparison 4 Calibration Of Chambers, Ovens, Furnaces Using Nine RTD s with multi Channel Data Logger 200 ºC to 1200 ºC 2.9 C 3.6 C 3.6 C By comparison 5 DIGITAL THERMO- HYGROMET ER # Using Temperature & Humidity Chamber with RH Probe 30 % RH to 90 % 25 C 2.1 %RH 1.7 %RH 2.1 %RH By comparison * Only for Electro-technical discipline; scope shall be recommended parameter vise (where applicable) and the ranges may be mentioned frequency vise. ** NABL 143 shall be referred for the recommendation of CMC + Remarks shall also include whether the same scope is applicable for site calibration as well. NABL 130 shall be referred while recommending the scope for site calibration. Signature, Date & Name of Lab Representative Signature, Date & Name of Assessor(s) Signature, Date & Name of Lead Assessor Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 18 of 19

20 8.14 Minimum Requirement for Accreditation: Reference document from NPL or any other Accreditation Bodies (under valid APLAC/ILAC MRA) /National Metrology Institute (NMI) shall be considered for putting value/range of CMC wherever applicable for accreditation. REFERENCES (National/ International Standards) IS: Method of calibrating Liquid-In Glass Thermometer. IS: 7358 Specification of thermocouple. EURAMET cg-8: Calibration of Thermocouple ASTM E220 13: Standard Test method for calibration of Thermocouple by comparison method. DKD-R5-1: Calibration of Resistance Thermometer. DKD-R5-7: Calibration of Climate chamber API (6) standard 20H: Calibration of Industrial Furnace JCGM 200:2012 International vocabulary of metrology Basic and general concepts and associated terms (VIM) ISO Part 2: Measurement management systems Requirements for measurement processes and measuring equipment. MSL technical Guide 22: Calibration of Low temperature Infrared Thermometers VDI/VDE 3511 Part 4.3 High Temperature Issue No: 06 Issue Date: 19-Dec-2017 Amend No: 00 Amend Date: - Page No: 19 of 19

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