uRohm: uncertainty contribution due to measurement uncertainty in the calibration of the ohmmeter:
Example: According to the calibration certificate, the measurement uncertainty of the multimmeter is 0,020 Ω (k = 2) and the standard uncertainty thus is 10 mΩ.
uRts: uncertainty contribution due to time stability of multimeter (user manual)
Example: uRts=0.5mΩ
uRt: uncertainty contribution due to ambient temperature influence (user manual). Outside certain ambient temperature interval, the component is significant and can be accessed using user manual. Within prescribed temperature interval the component is negligible.
uRres: uncertainty component due to multimeter resolution – least significant bit LSB. Example: The limited resolution of the ohmmeter of 0,001 Ω allows a reading within ±0,0005 Ω. From this a standard uncertainty of 0.5 mΩ / √3 = 0,29 mΩ.
Multimeter additional noise if multiplekser is used.
Uncertiainty linked to the connection: The reference probe is four wire connected to multimeter and the uncertainty associated with this connection type is taken to be negligible.