Fluke 8558A - Page 68

8588A/8558A
Operators Manual
64
Enter the appropriate information for each of the fields listed with the navigation
keys and numeric keypad.
• Asset number (shown as the first field on the shunt information line of
the main DCI Ext Shunt screen)
• Manufacturer
• Model (shown as the second field on the shunt information line)
• Serial Number
• Resistance value: Use the numeric keypad and  to input the
resistance value of the shunt, for example from the most recent
calibration certificate. Resistance value is displayed as the fourth field in
the shunt information line.
• Maximum current: Use the numeric keypad and  to input the
maximum current that can be applied to the shunt without causing a
resistance value change. Maximum current is displayed as the third field
in the shunt information line.
• Power ref. level: Enter the current level used when calibrating the shunt
resistance value.
• Power coefficient: Enter the power coefficient of the shunt, in μA/A.
The Power ref level and Power coefficient entries show the uncertainty of the
displayed current due to self-heating of the shunt. The Power uncertainty is
shown as an integer value between 0 μA/A and 999,999 μA/A, and does not
affect the calculated current. See the screen below.
Calculation of the Power Uncertainty:
Power uncertainty = Power coefficient x {1 - (Measured current/Power ref level)
2
}
Push  to (Save as new) the ACI Ext Shunt, or push  (Save
changes) to save the shunt changes. See the screen below:
iei020.png