Specifications

E-1

APPENDIX E

Q Measurement accuracy calculation

Q measurement accuracy for auto balancing bridge type instruments is not specified directly as ±%.

Q accuracy should be calculated using the following equation giving the possible Q value tolerance.

Where: Qt is the possible Q value tolerance

Qm is measured Q value

∆D is D measurement accuracy

For example, when the unknown device is measured by an instrument which has D measurement

accuracy of .001, and the displayed Q value is 200, the Q tolerance is calculated as:

This result means that the true Q value will be between 167 and 250.

Note: The following equation may be used to calculate the Q value tolerance. (The result is the same

at that from the above equation.)

Qm D

Qm D()

=±

∆

Qt =

200

001

005 001

∅