Percentage Error Calculation For Accuracy Verification Testing; Typical Sources Of Test Errors; Accuracy Verification Test Points - Siemens 9410 Series User Manual

9410 series

Percentage error calculation for accuracy verification testing

Typical sources of test errors

Accuracy verification test points

188
Round the number up to the nearest integer: Number of pulses = 9
Accuracy verification testing requires you to calculate the percentage error between
the meter being tested and the reference/standard.
Calculate the percentage error for every test point using the following formula:
Energy error = (EM - ES) / ES x 100%
Where:
• EM = energy measured by the meter under test
• ES = energy measured by the reference device or energy standard.
NOTE: If accuracy verification reveals inaccuracies in your meter, they may be
caused by typical sources of test errors. If there are no sources of test errors
present, please contact your local Siemens Industry representative.
If you see excessive errors during accuracy testing, examine your test setup and test
procedures to eliminate typical sources of measurement errors.
Typical sources of accuracy verification testing errors include:
• Loose connections of voltage or current circuits, often caused by worn-out
contacts or terminals. Inspect terminals of test equipment, cables, test harness
and the meter under test.
• Meter ambient temperature is significantly different than 23 °C (73 °F).
• Floating (ungrounded) neutral voltage terminal in any configuration with
unbalanced phase voltages.
• Inadequate meter control power, resulting in the meter resetting during the test
procedure.
• Ambient light interference or sensitivity issues with the optical sensor.
• Unstable power source causing energy pulsing fluctuations.
• Incorrect test setup: not all phases connected to the reference device or the
energy standard. All phases connected to the meter under test should also be
connected to the reference meter/standard.
• Moisture (condensing humidity), debris or pollution present in the meter under
test.
The meter should be tested at full and light loads and at lagging (inductive) power
factors to help ensure testing over the entire range of the meter.
The test amperage and voltage input rating are labeled on the meter. Refer to the
installation sheet or data sheet for your meter's nominal current, voltage and frequency
specifications.
Verifying accuracy
7EN05-0336-03