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