Total Measurement Error

To compute the total measurement error, add the reading error and range error. You can then convert the total measurement error to a “percent of input” error or a “ppm (part-per- million) of input” error as shown below.

Total Measurement Error

% of input error = -------------------------------------------------------------X 100

Input Signal Level

Total Measurement Error , ,

ppm of input error = -------------------------------------------------------------X 1 000 000

Input Signal Level

Error Example

Assume that a 5Vdc signal is input to the multimeter on the 10 Vdc range. Compute the total measurement error using the 90-day accuracy specifications: ± (0.0020% of reading + 0.0005% of range).

Reading error

= 0.0020% x 5Vdc

= 100μV

Range error

= 0.0005% x 10Vdc

= 50μV

Total error

= 100μV + 50μV

= ± 150μV

 

 

= ± 0.0030% of 5Vdc

 

 

= ± 30 ppm of 5Vdc

Appendix A

HP E1312A and HP E1412A Multimeter Specifications 181

Page 181
Image 181
HP WaterSkis E1412A, WaterSkis E1312A manual Total Measurement Error