Meter: Test View
Until now, the usual method for testing of energy meters has been to use a stabilized, but not very accurate, power source, in combination with a high-precision reference meter. OMICRON's approach significantly simplifies meter testing. By using state-of-the-art hardware technology, OMICRON provides test sets that are so accurate and stable, that the signal source itself becomes the reference and make a reference meter unnecessary.
The CMC test sets not only provide the test signals, but also have inputs for the meter pulses allowing closed loop testing. To this end, optical scanning heads for capturing pulses emitted by the meters (infrared LEDs) are available. Meter allows for manual or automated testing of energy meters.
Each line of the test table represents a test point, which can be run in one of the following modes:
- Load test - Accuracy of measurement unit (time power method)
- Mechanism test - Accuracy of entire meter including display
- Gated Mechanism test - Testing internal meter registers
- Injection test - Quick check (wiring, sense of rotation)
- No-load test - No start-up at zero load
- Creep test - Start-up at low loads
Meter: Detail View
For testing the behavior of meters with harmonics or DC components, the following current signal waveforms are available:
- Sine
- Sine + Harmonics
- Sine + DC
The test can be performed with any balanced or unbalanced load for:
- Single phase meters (or a single measurement element of a 3-phase meter)
- 3-wire meters
- 4-wire meters
In a detail view, all parameters can be specified independently for each phase. Apparent, active and reactive power is indicated for each phase and the whole rotary system. Testing of the following meter functions is supported:
- Wh importing/exporting
- VArh importing/exporting
- VAh
- I2h and V2h (load/no-load losses of transformers)
- Qh (quantity hour)
Also operation in conjunction with an external reference meter is possible: When testing with a reference meter, the CMC is used as a current and voltage source. During a load test, the pulses of the meter under test as well as those of the reference meter are registered. The latter form the reference for error calculation.
Furthermore, testing against a 0.02 or 0.01 % reference before a test is run, using the same test points, can eliminate errors of the CMC by loading correction values.
