Maintaining ISO Compliance in Automated Procedures

Transcription

1 Maintaining ISO 1705 Compliance in Automated Procedure Preenter & Author: Jorge Martin Fluke Corporation PO 9090 M/S 6-30 Everett, WA, USA 9806 Phone: (45) ; Fax: (45) Abtract To meet the ISO 1705 requirement for accredited calibration procedure, almot all laboratorie have created a myriad of document and procee, epecially if an automated procedure i involved They uually comprie of an uncertainty analyi document, the automated accredited procedure, a calibration proce document with the calibration requirement and applicable pecification, the validation proce and repective data, the reviion control document, etc Their maintenance, management and control are one of the mot difficult tak of any laboratory Thi paper decribe how all thee document can be incorporated in a commercially available oftware product, greatly reducing the time pent on thee eential tak Introduction The proce of developing an accredited automated calibration procedure include everal phae 1 Collection of information about the unit under tet (UUT) Definition of the initial calibration trategy and guard band policy 3 Perform the preliminary uncertainty analye in accordance with NIST technical note Automatic calibration procedure that implement the uncertainty analyi and perform all the neceary calculation 5 Uncertainty analyi and procedure validation 6 Calibration procedure approval and releae 7 Laboratory taff training that, in the cae of a properly developed automated calibration procedure, can be minimal To document thee phae, the laboratory end up with a collection of everal document Since mot of them are conidered quality or technical record, they need to comply with ISO 1705 paragraph 43 Document Control and 41 Control of Record among other

2 Procedure interdependency Approval reference Reviion hitory Calibration requirement Fluke Corporation MET/CAL Procedure ============================================================================= INSTRUMENT: Clarke-He 6000: (1 year) ACAL VER IEEE CH5500,884 DATE: AUTHOR: Jorge Martin REVISION: 10 ADJUSTMENT THRESHOLD: 70% NUMBER OF TESTS: 80 NUMBER OF LINES: 64 CONFIGURATION: Fluke 884A CONFIGURATION: CH5500 ============================================================================= STEP FSC RANGE NOMINAL TOLERANCE MOD1 MOD 3 4 CON APPROVALS: The procedure review and approval i managed by the Corporate Document control ytem a per LPD 300, Technical Quality Manual METCAL VERSION Thi procedure i NOT executable in MET/CAL verion below Ver SUBPROCEDURES CALLED: Sub Check C-H 6000 Range - Rev CALLING PROCEDURES: N/A DOS CALLS: N/A DOS FILES: N/A PIC FILES: N/A VARIABLE USE: L[1], REVISION HISTORY: 10-10/06/004, Jorge Martin Initial procedure Specification METCAL executable procedure Guard band policy Uncertainty analyi Validation method Validation data UNCERTAINTY ANALYSES: 1 - Calibration Sytem Direct comparion between C&H 5500 Phae tandard and UUT, through BNC (50 Ohm) equal length cable At tet 3-7, Analog Output, in addition to the Phae tandard, a Fluke 884 DMM i connected to the UUT Analog output through a wire hielded banana plug - Uncertaintie calculation method The uncertaintie are calculated according to the NIST Technical Note 197 The following chapter will etablih, for each parameter object of thi analye, the Uncertainty Source, their type (whether A or B), tatitical ditribution, confidence level and Senivity coefficient The effective degree of freedom are calculated uing the Welch-Satterthwaite formula and the coverage factor i calculated uing the invere of the Student' t-ditribution The actual uncertainty calculation are done by Met/Cal in real time, uing verion 701 (or higher) capabilitie, baed in the mathematical model and Uncertainty ource defined in thi analye The reported uncertainty can't be maller then the Accredited Bet Uncertainty tated in the Scope of the Accreditation 3- Uncertainty analye by Verification Parameter 31 - Angle tracking accuracy, Amplitude linearity, Amplitude range tracking and Offet control tet Direct connection between C&H 5500 Phae tandard and UUT, through BNC (50 Ohm) equal length cable Mathematical model of the meaurement: Ph_iuut = Ph_ + dph_ - dph_iuut Ph_iuut - Phae angle indicated by the UUT Ph_ - Phae angle generated by the calibrator dph_ - Error of calibrator dph_iuut - Error due to the finite reolution of the UUT d - delta number of reading: 3 Reading thrown away: Range/Applied Source Decription Prob Dit Ci DF Note U All Range Std C&H 5500 Accuracy B/Normal U1 uut UUT Reolution B/Rect 1 00 S uut Reading Std Dev A/Normal 1 n-1 S1 Note: 1 - One year Phae angle tandard accuracy pecification (manual) PROCEDURE VALIDATION 1 - Validation method Procedure validated by comparion with manual meaurement The validation data i available at: w:\\callab\grponly\metcal Acc Proc & Validation\CH6000\ CH6000_Prog_Validationxl - Validation information Jorge Martin, reviewed by Neil Faulkner It i not propoed that all relevant information that i already written elewhere hould be included inide the procedure Intead it i propoed that a template be ued to keep mot of the neceary information or data integrated, conitent, referenced, and protected in the procedure itelf Since the laboratory want to have an automated procedure, why not keep all the important information in one place and readily available to whom ever may need it, both for internal laboratory ue or external aement

3 The challenge Develop a fully automated procedure to calibrate the clarke he model 6000 Phae Meter which alo include all the neceary uncertainty analyi and information to comply with ISO1705 requirement in a ingle document The elected oftware to upport thi procedure i MET/CAL calibration management oftware A tandard, we are going to ue the clarke he model 5500 Phae Standard and the Fluke 884A DMM with IEEE-488 interface for automated control We are going to decribe tep by tep how to achieve thi goal The automated calibration procedure ued to exemplify the proce i imple, although it offer ome challenge that require the ue of many feature of the calibration oftware Other conideration Once the MET/CAL calibration procedure i approved, it mut be aved in a written protected directory to avoid any non authorized change The ISO 1705 document control requirement i fundamental to maintain accreditation and the laboratory commitment to utain high level of tandardization and quality of ervice to the cutomer The calibration laboratory mut be able to determine without any doubt the procedure ued to calibrate a particular piece of equipment at any particular time Neverthele, thi fact i not enough if it can t identify all the other information, reference and engineering knowledge put in the procedure development and maintenance Even wore, i it inability to keep that information conitent through the life of the calibration procedure It would be almot impoible and not even deirable to incorporate all neceary document in the actual calibration procedure It i not our aim to copy the uer or ervice manual, pecification and the validation data into the calibration procedure, but we mut know exactly what reference document were ued and preumption were made Thoe document that are readily available in the laboratory can be imply referred to in the procedure, keeping in mind that they have to be unequivocally identified Other Referred document METCAL executable procedure + ISO 1705 compliant template = ISO 1705 compliant procedure Intruction manual Validation data

4 The upporting template The MET/CAL procedure language i compoed of a number of FSC (Function Selection Code) that comprie the executable part of the automated procedure Since thi oftware offer the poibility of adding non-executable text in the form of comment, we are going to take advantage of that to attach the neceary information and achieve our goal of building a ISO1705 compliant automated procedure After the baic MET/CAL header the following information hould be added a comment (line tarting with the character ): Sub procedure called: Lit all the ub procedure called by thi procedure and include their reviion Note: MET/CAL ave in the MET/TRACK data bae calibration record the verion of the main procedure executed However the ubprocedure can have impact in the meaurement performed or it execution, o it mut be controlled a trictly a the main If a ubprocedure i reviewed the main mut updated to reflect the change Since MET/CAL allow the uer to define the verion field, each lab can implement hi own reviion policy At the Fluke ervice center we are uing the xxyy format It wa decided that major reviion are the one that have impact in the meaurement or in the procedure execution Thi implie a new validation and approval (change the integer portion of the reviion field, ie 0305 to 0400) Minor change need to be approved but don t require a full validation, (only the decimal portion of the field i updated ie 0400 to 0401) Calling Procedure: Lit all external procedure calling thi procedure Note: If thi i a ubprocedure, thi i the lit of procedure that mut be updated External DOS File: Lit all external DOS File called by thi procedure (ie Correction file (cor), value file (val)) Note: Exhautive lit of all the correction file, value file and other, ued in the procedure PIC file: Lit of all picture ued INTRODUCTION AND PURPOSE: Brief explanation about the cope of the procedure and the compliance with tandard Note: Alo reference the ource proce that thi procedure i implementing (ie Manufacturer recommendation, international tandard, accreditation body policie and recommendation or other) Approval: Reference the document that define the laboratory calibration procedure approval proce Note: In mot calibration laboratorie the approval proce and reponibilitie are detailed in the Quality manual and implemented uing commercial document management oftware

5 Reviion hitory: xz mm/dd/yyyy author Reaon that triggered the reviion and a uccinct decription Note: the reviion decription mut be enough to identify what wa changed in the procedure and ubtantiate the attribution of a major or minor reviion tatu Reference: Lit the documentation that upport the development of the calibration procedure ie UUT ervice manual number xxxx, reviion yyyy Standard uer manual, dated mm/yy UUT Specification: Reference the document that upport the tated pecification ie According to UUT Service manual number xxxxxx reviion yyyyyy Calibration Condition: Reference to the calibration condition that the laboratory mut meet to perform thi calibration in order to achieve the tated uncertaintie Minimum environmental requirement, acceorie and other requiite (The next element can be inerted after the executable procedure) Guard Band: Information about the guard band trategy implemented in thi calibration procedure if any Note: The guard band trategy doen t have to be the ame along the procedure; it can be different for divere parameter or even within the ame parameter Ue enough detail to make clear what trategy wa implemented for each tet

6 Uncertainty Analyi: 1 Calibration Sytem Brief decription of the calibration ytem implemented in thi procedure Note: Enough detail hould be provided about the model to upport the ubequent uncertainty analyi Uncertaintie calculation method The uncertaintie are calculated according to the NIST Technical Note 197 The following ection will etablih, for each parameter object of thi analyi: Uncertainty ource Source type (whether A or B) Probability denity function Confidence level Senitivity coefficient The effective degree of freedom are calculated uing the Welch-Satterthwaite formula and the coverage factor i calculated uing the invere of the Student t-ditribution The actual uncertainty calculation are done by MET/CAL in real time, uing verion 71 capabilitie, baed on the mathematical model and uncertainty ource defined in thi analyi 3- Uncertainty analyi by calibration parameter 3x Parameter Y Detailed decription of the calibration ytem for thi parameter Mathematical model of the meaurement Number of reading: Number of effective reading per meaurement Reading thrown away: Number of initial reading dicarded (Budget header) Range Source Decription Type/PDF Ci DF Note U Note: Range Applicable range Source Source of uncertainty Decription identification of the uncertainty Type/PDF type of uncertainty (A or B) and Probability ditribution function aociated with thi uncertainty element Ci Senitivity coefficient DF Degree of freedom of thi ource Note Reference to complementary note U MET/CAL variable attributed to the uncertainty component (ex U1, U4) Procedure Validation 1 Validation method Brief decription of the method ued to validate the procedure Validation data or reference to where it i available in the laboratory hould alo be included Validation information Provide information about: validation date, who did it, and who approved it

7 Mathematical model The calibration of the clarke-he model 6000 Phae Meter i compried of two part with ditinct mathematical model; one related with the phae calibration and the other with the calibration of the phae-to-voltage converion performed inide the UUT 1 Phae Uncertainty Evaluation c-h 5500 Phae tandard c-h 6000 Phae meter UUT Meaurement mathematical model: θ iuut = θ + δθ δθ iuut θ iuut - Phae angle indicated by the UUT θ δθ iuut - Phae angle generated by the calibrator - Error of the calibrator δθ - Error due to the UUT Expanded uncertainty expreion: u uiuut U = k + + u 3 u iuut rand - C&H 5500 Phae calibrator accuracy u - UUT reolution u - Experimental Standard deviation of the reading k rand - Coverage factor Note: other ource of uncertainty were evaluated and found to be inignificant

8 Analog Output Uncertainty Evaluation c-h 5500 Phae tandard θ c-h 6000 Phae meter UUT Fluke 884A Voltmeter x K V out V Meaurement mathematical model: V = ( θ + δθ ) ( K uut + δk uut ) δv V V θ - Voltage value indicated by the tandard voltmeter δ - Error of the voltage indicated by the voltmeter δθ uut - Phae angle generated by the calibrator - Error of the calibrator K - Phae-to-voltage converion factor (K= -10 mv/ ) δ - Error of the UUT phae-to-voltage output converion K uut V V θ = 1 V = K uut C = 1 (Voltage enitivity coefficient) V = 0 01 C (Phae enitivity coefficient) θ Expanded Uncertainty expreion: u uv U = k Cθ + CV + u u V - C&H 5500 Phae calibrator accuracy u - Voltmeter accuracy rand rand u - Experimental tandard deviation of the reading k - Coverage factor Note: other ource of uncertainty were evaluated and found to be inignificant

9 Implementation I m going to preent a poible implementation of the ISO 1705 compliant template in the original automated calibration procedure Thi template can be implemented in any exitent automated procedure provided that the oftware i able to be the complete uncertainty calculation engine and the uer make the neceary change to enable it Some of the tatement are cloely tied with the calibration laboratory in which they were implemented Every procedure mut be evaluated and validated in the place where it i going to be ued and with the reource and condition available in the calibration laboratory Since we want to ue the comment field of MET/CAL to complete our documentation tak, the uncertainty analyi mut be documented without the benefit of an equation editor Propoed ISO 1705 compliant template to calibrate the clake-he 6000 Phae Meter Fluke Corporation MET/CALProcedure ======================================================================= INSTRUMENT: Clarke-He 6000:(1 yr) ACAL VER IEEE CH5500,884 DATE: AUTHOR: Jorge Martin REVISION: 10 ADJUSTMENT THRESHOLD: 70% NUMBER OF TESTS: 80 NUMBER OF LINES: 64 CONFIGURATION: Fluke 884A CONFIGURATION: CH5500 ======================================================================= STEP FSC RANGE NOMINAL TOLERANCE MOD1 MOD 3 4 CON SUBPROCEDURES CALLED: Sub Check C-H 6000 Range - Rev CALLING PROCEDURES: N/A External DOS file: N/A PIC FILES: PhaeConnectionjpg (ch5500 to ch6000 phae connection) PhaeVoltConjpg (Analog phae-to-voltage converion connection) INTRODUCTION AND PURPOSE: The purpoe of thi procedure i to calibrate the clarke-he 6000 Phae Meter, according to the manufacturer' recommendation, publihed in Reference 1, Performance Tet Thi procedure complie with the ISO 1705 requirement and the accreditation body policie

10 Thi ection can be more or le detailed, depending on your quality manual and document control ytem APPROVALS: The procedure review and approval i managed by the Corporate Document control ytem a per LPD 300, Technical Quality Manual REVISION HISTORY: 10-10/06/004, Jorge Martin Initial releae Reference: 1 clarke-he 6000 Phae Meter Intruction manual Rev 1996 clarke-he 5500 Phae Standard Intruction manual - Rev clarke-he 5500 Errata heet for 00 khz modification of model Rev Fax from clarke-he providing official notification of 5500 new pecification - dated 10 July Fluke 884A Digital Multimeter Intruction manual - Rev 3, 7/ UUT SPECIFICATIONS: According to Reference CALIBRATION CONDITIONS: Minimum warm-up period: UUT half-hour Standard one hour Thi procedure can be performed with an ambient temperature of 3 ºC ±5 ºC and a relative humidity equal or le than 80% Cable: x Tektronix , BNC (50 Ohm) cable or equivalent with equal length GUARD BAND: N/A UNCERTAINTY ANALYSES: 1 - Calibration Sytem Direct comparion between C&H 5500 Phae tandard and UUT, through BNC (50 Ohm) equal length cable At tet 3-7, Analog Output, in addition to the Phae tandard, a Fluke 884 DMM i connected to the UUT analog output through a wire hielded banana plug - Uncertaintie calculation method The uncertaintie are calculated according to the NIST Technical Note 197 The following ection will etablih, for each parameter object of thi analyi, the Uncertainty Source, their type (whether A or B), the tatitical ditribution, confidence level and Senivity coefficient The effective degree of freedom are calculated uing the Welch- Satterthwaite formula and the coverage factor i calculated uing the invere of the Student' t-ditribution The actual uncertainty calculation are done by MET/CAL in real time, uing verion 701 (or higher) capabilitie, baed on the mathematical model and Uncertainty ource defined in thi analyi

11 ch 6000 ch 5500 The reported uncertainty can t be maller then the accredited bet uncertainty tated in the cope of accreditation 3- Uncertainty analye by verification parameter 31 - Angle tracking accuracy, Amplitude linearity, Amplitude range tracking and Offet control tet Direct connection between ch 5500 Phae tandard and UUT, through BNC (50 Ohm) equal length cable Mathematical model of the meaurement: Ph_iuut = Ph_ + dph_ - dph_iuut Ph_iuut - Phae angle indicated by the UUT Ph_ - Phae angle generated by the calibrator dph_ - Error of calibrator dph_iuut - Error due to the UUT d - delta number of reading: 3 Reading thrown away: Range/Applied Source Decription Prob Dit Ci DF Note U All Range Std C&H 5500 Accuracy B/Normal U1 uut UUT Reolution B/Rect 1 00 S uut Reading Std Dev A/Normal 1 n-1 S1 Ci Senitivity coefficient DF Effective degree of freedom U - MET/CAL uncertainty component Note: 1 - One year Phae angle tandard accuracy pecification (manual) θ iuut u uiuut U = k + + u 3 = θ + δθ δθ rand iuut

12 Fluke 884A 3 - Analog output tet Direct connection between C&H 5500 Phae tandard and UUT, through BNC (50 Ohm) equal length cable In addition to the Phae tandard, a Fluke 884A DMM i connected to the UUT analog output through -wire hielded banana plug Mathematical model of the meaurement: V_ = (Ph_ + dph_)(k_uut + dk_uut) - dv_ V_ - Voltage value indicated by the Standard voltmeter Ph_ - Phae angle generated by the calibrator dph_ - Error of the phae tandard K_uut - Phae meter converion factor (- 001 V/ ) dk_uut- Error of the analog output converion dv_ - Error of the voltage indicated by the Standard voltmeter d - delta number of reading: 3 Reading thrown away: ch 6000 ch 5500 ( θ + δθ ) ( K uut + δkuut ) δv Range/Applied Source Decription Prob Dit Ci DF Note U All Range PhStd C&H 5500 Accuracy B/Normal , U3 VStd voltmeter Accuracy B/Normal U1 VStd Reading Std Dev A/Normal 1 n-1 S1 Ci Senitivity coefficient DF Effective degree of freedom U - MET/CAL uncertainty component Note: 1 - Senivity coefficient due to the UUT Converion factor (K=-10 mv/ ) pd(v_)/pd(ph_)= K => Ci(Ph)=-001 pd(v_)/pd(v_)= 1 => Ci(V)=1 pd-partial derivative - One year Phae angle tandard accuracy pecification (manual) 3 - Fluke 884A 90day pec, when offet control i not ued (manual) u uv U = k Cθ + CV + u V = rand

13 The MET/CAL mfile capabilitie can be ued to analyze and preerve the validation data All the original reading and calculation are available in thi file that can be exported to a preadheet for poterior analyi The mfile file can alo be ued to debug the program and evaluate the uncertainty analyi with the actual reading PROCEDURE VALIDATION 1 - Validation method Procedure validated by comparion with manual meaurement The validation data i available at: w:\\callab\ MET/CAL Validation\CH6000\CH6000_Prog_Validationxl - Validation information Jorge Martin, reviewed by Neil Faulkner Although the template hown here i an uninterrupted lit of tatement, it can be broken into two or more egment to improve readability or to comply with particular laboratory requirement In our application we have broken it in two part, one at the beginning of the MET/CAL procedure contain the more generic information and requirement The econd, becaue it i more technical it can be inerted at the end of the executable procedure Anyhow, thi i jut a cometic deciion and not a technical requirement a long a all the neceary information i readily available or referenced in the procedure SUBPROCEDURES CALLED: CALIBRATION CONDITIONS: Firt part of the template MET/CAL Automated procedure GUARD BAND UNCERTAINTY ANALYSES Second part of the template PROCEDURE VALIDATION Concluion It i poible to build an automated calibration procedure that keep all the neceary information and data integrated, conitent, referenced, protected and readily available It i out of the cope of thi paper to provide detailed information on how to implement the automated meaurement portion of thi template with the MET/CAL FSC It can be implemented with any automated calibration oftware that i able to perform the neceary uncertainty calculation at run time, according with the NIST technical note 197 The baic tep to implement thi proce are: 1 Etablih the calibration proce Invet the neceary reource and know-how to develop a complete uncertainty analyi (with the mathematical model and the expanded uncertainty expreion) 3 Fill the ISO/IEC 1705 compliant template to preerve the available information

14 4 Develop the automated calibration procedure that i alo the whole uncertainty calculation engine In thi tep it i eential that what you have etablihed in the uncertainty analyi i meticulouly implemented Say what to do and do what you ay 5 Define a comprehenive validation proce 6 Ue the mfile or other form of reult to document the validation proce 7 Perform the review and approval proce 8 Update the ISO 1705 compliant template with the lat data 9 Releae the procedure Although the development of thi ISO 1705 template i fairly new in our laboratory, we have already implemented it in everal calibration procedure with ucce I m certain that it i a ueful tool to improve the laboratory quality of ervice Thi template i a live document that can be improved through the laboratory experience and meet other requirement Reference: [1] ISO/IEC 1705:1999(E), General requirement for the competence of teting and calibration laboratorie [] NIST technical note 197: 1994 edition, Guideline for Evaluation and Expreing the Uncertainty of NIST Meaurement Reult [3] clarke-he model 5500 phae tandard intruction manual [4] clarke-he model 6000 phae meter intruction manual [5] Fluke 884A digital multimeter intruction manual, Rev 3 7/96 [6] Nichola, Matthew, Guardbanding Uing Automated Calibration Software, NCSLI 004 [7] Nichola, Matthew, Implementing ISO 1705 Meaurement Uncertainty Requirement in Software NCSL 1999