calibration

CALIBRATION BOOK......Page 1 PREFACE......Page 3 CONTENTS......Page 4 SCOPE......Page 6 WHAT TIME IS IT?......Page 7 Why the measurements are needed......Page 8 Measurement results have high economical impact......Page 9 Legislation or other industry authorities may require measurement......Page 10 Distributed manufacturing......Page 11 Calibration practices in a nutshell......Page 13 1.1. Quality management standards......Page 14 1.2. Traceability......Page 15 1.3. Calibration documentation......Page 16 Validity of calibration......Page 17 Recalibration interval......Page 18 2. METROLOGY AND CALIBRATION SERVICES......Page 19 Legal metrology......Page 20 Metrology......Page 22 Accreditation......Page 23 2.2. National measurement standard laboratories......Page 24 Accredited laboratories......Page 25 Organization and management......Page 26 Choosing reference equipment......Page 27 3. CALIBRATION ACTIVITIES......Page 28 What should we do with the calibration results?......Page 30 Laboratory and field calibration......Page 31 Equipment required for field calibration......Page 32 Disadvantages of field one-point calibration......Page 33 Disadvantages of field multi-point calibration......Page 34 Field spot checking......Page 35 Typical calibration interval......Page 36 Shortening the calibration interval......Page 37 3.4. Calibration methods by the user......Page 38 Stabilization and sampling......Page 40 Uncertainty estimation......Page 41 Presenting the results......Page 42 Choosing reference equipment......Page 44 Two pressure (2p) generators......Page 45 Combined two temperature (2t), two pressure (2p) generators......Page 46 Dry gas supplies......Page 47 Climate chambers......Page 48 Reference equipment......Page 49 Mixing ratio (r)......Page 51 Using a moist air (gas) generator as reference......Page 52 Unit conversion......Page 54 Hygrometer......Page 55 One-point calibration......Page 56 Stabilization time is not sufficient:......Page 57 Dewpoint temperature calibration......Page 58 Calibration......Page 60 Faulty condensation in the dewpoint meter......Page 61 4.2. Temperature calibration......Page 63 ITS-90 Temperature Scale......Page 64 Fixed points......Page 65 Calibration Baths......Page 66 Climate chamber......Page 67 SPRT Thermometers......Page 68 Liquid-in-glass thermometers......Page 69 Resistance bridges......Page 70 Digital multimeters......Page 71 One-point calibration......Page 73 Calibration in calibration bath......Page 74 Heat conducted via sensor wires......Page 75 4.3. Pressure calibration......Page 76 Conventional pressure balance......Page 77 Mercury manometer......Page 78 Electrical transfer standard and electrical transfer standard integrated into a pressure controller......Page 80 One-point calibration at atmospheric pressure......Page 81 Full calibration......Page 82 Leak in pressure system......Page 83 Accredited calibration services......Page 84 Customized maintenance services......Page 85 Service center locations......Page 86 ADJUSTMENT (OF A MEASUREMENT INSTRUMENT)......Page 88 CORRECTION FACTOR......Page 89 DISPLAYING......Page 90 HYSTERESIS ERROR......Page 91 INDEPENDENT LINEARITY......Page 92 MEASUREMENT EQUIPMENT......Page 93 RECORDING DEVICE......Page 94 REFERENCE, (MEASUREMENT) STANDARD, ETALON......Page 95 REPEATABILITY (OF RESULTS OF MEASUREMENTS)......Page 96 SENSOR......Page 97 TRACEABILITY (OF MEASUREMENT)......Page 98 UNCERTAINTY (OF MEASUREMENT)......Page 99 APPENDIX B: ABBREVIATIONS......Page 100 APPENDIX C: UNCERTAINTY CALCULATION......Page 102 Uncertainty types......Page 103 TYPE A EVALUATION OF STANDARD UNCERTAINTY......Page 104 TYPE B EVALUATION OF STANDARD UNCERTAINTY......Page 105 Typical uncertainty factors......Page 107 Long-term stability of the reference equipment......Page 108 Uncertainty of the reference equipment caused by temperature......Page 110 Measurement Model......Page 111 Uncertainty Budget......Page 112 Expanded Uncertainty......Page 114 Presenting Uncertainty......Page 115 REFERENCES......Page 116 www.vaisala.com......Page 118