Technical Reference

General Guidelines for Uncertainty factor considerations

ET Discipline

 

1. 3 1/2 DMM / 4 1/2 DMM - direct method

i) Type A- Uncertainty due to repeatability
ii) Type B- Ub1 Uncertainty due to resolution of UUC
iii) Type B- Ub2 Uncertainty due to Accuracy of Calibration standard/s (if there are more than one calibration standard
the consider RSS (Root Sum of Squares) value of two contributions)
iv) Type B- Ub3 Uncertainty due to Uncertainty reported in Calibration standard/s’s calibration certificate
v) Type B- Ub4 Uncertainty due to Stability of Calibration Standard (if a source & if not included in Ub2 by the manufacturer)

1A comparison method - For AC/ DC Current and AC/DC Voltage

i) Type A- Uncertainty due to repeatability
ii) Type B- Ub1 Uncertainty due to resolution of UUC
iii) Type B- Ub2 Uncertainty due to Accuracy of Calibration standard/s (if there are more than one calibration standard
the consider RSS (Root Sum of Squares) value of two contributions)
iv) Type B- Ub3 Uncertainty due to Uncertainty reported in Calibration standard/s’s calibration certificate
v) Type B- Ub4 Uncertainty due to Stability of Source used for Calibration (if not evaluated, consider 10% of standards uncertainty)

2. Process calibrator - Direct method - Temperature Simulation - Type, K, J, S and RTD PT 100

i) Type A- Uncertainty due to repeatability
ii) Type B- Ub1 Uncertainty due to resolution of UUC
iii) Type B- Ub2 Uncertainty due to Accuracy of Calibration standard/s (if there are more than one calibration standard
the consider RSS (Root Sum of Squares) value of two contributions)
iv) Type B- Ub3 Uncertainty due to Uncertainty reported in Calibration standard/s’s calibration certificate
v) Type B- Ub4 Uncertainty due to Stability of Calibration Standard (if a source & if not included in Ub2 by the manufacturer)
/ Max.RJC error specified by the manufacturer.

3. LCR Meter - Direct method - Inductance, Resistance and Capacitance

i) Type A- Uncertainty due to repeatability
ii) Type B- Ub1 Uncertainty due to resolution of UUC
iii) Type B- Ub2 Uncertainty due to Accuracy of Calibration standard/s (if there are more than one calibration standard
the consider RSS (Root Sum of Squares) value of two contributions)
iv) Type B- Ub3 Uncertainty due to Uncertainty reported in Calibration standard/s’s calibration certificate
v) Type B- Ub4 Uncertainty due to Stability of Calibration Standard (if a source & if not included in Ub2 by the manufacturer)
vi) Type B- Ub5 Uncertainty due to change in calibration temperature.

4. Digital Timer - comparison method - Time

i) Type A- Uncertainty due to repeatability
ii) B- Ub1 Uncertainty due to resolution of UUC
iii) Type B- Ub2 Uncertainty due to Accuracy of Calibration standard/s (if there are more than one calibration standard
the consider RSS (Root Sum of Squares) value of two contributions)
iv) Type B- Ub3 Uncertainty due to Uncertainty reported in Calibration standard/s’s calibration certificate
v) Type B- Ub4 Uncertainty due to Human reaction time error (consider 120ms for manual On / off of UUC)

5. HV probe with DMM - comparison method - High AC / DC Voltage

i) Type A- Uncertainty due to repeatability
ii) Type B- Ub1 Uncertainty due to resolution of UUC
iii) Type B- Ub2 Uncertainty due to Accuracy of Calibration standard/s (RSS (Root Sum of Squares) value of two contributions: Multimeter & HV probe)
iv) Type B- Ub3 Uncertainty due to Uncertainty reported in Calibration standard/s’s calibration certificate
v) Type B- Ub4 Uncertainty due to Stability of the High voltage transformer used. (if not evaluated then consider 10% of the uncertainty of the standard)

Mechanical Discipline

1. Push - Pull Gauge - Parameter Force - Uncertainty Budget in % ( Estimated for relative Value/Scale)

i) Type A- Uncertainty due to repeatability
ii) Repeatability b’ – Rectangular Type B Ö3
iii) Zero Error F0 – Rectangular Type B Ö3
iv) Resolution r – Rectangular Type B Ö3
v) Hysteresis h – Rectangular Type B Ö6

vi) Error of indication – Rectangular Type B Ö6

vii) Applied Force Uncertainty Utcm – Normal

2. Durometer - Parameter - Hardness - Uncertainty Budget in % ( Estimated for minimum scale Value)

i) Type A- Uncertainty due to repeatability
ii) Repeatability b’ – Rectangular Type B Ö3
iii) Zero Error F0 – Rectangular Type B Ö3
iv) Resolution r – Rectangular Type B Ö3
v) Applied Force Uncertainty Utcm – Normal