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Compact Clamp Meter Comparison — How to Read Spec Sheets Critically

2026年05月12日

Spec-sheet marketing tricks make brand comparison hard — here is how EK engineers see through them.

What Spec-Sheet Marketing Hides

Two compact clamp meters can look identical on the marketing page and differ by 5 × in field accuracy. EK service teams perform clamp meter comparison tests for procurement clients — the failure modes are predictable.

1. Accuracy Quoted at One Temperature

"±1.0 % at 23 °C" hides everything. Real spec needs ±1.5 % across -10 to +50 °C. Cheap meters drift 0.1 % per °C; the EK-G645 specifies ±1.5 % full operating range.

2. Crest Factor Quoted at Mid-Range

A meter with CF=3.0 at 50 % range may have CF=1.5 at 100 %. Real spec quotes CF at full scale — the EK-G645 holds 3.0 across the entire 1200 A range.

3. "True-RMS" Without AC + DC

Some "true-RMS" meters only do AC RMS with DC blocked. For solar combiner outputs and battery work you need AC + DC RMS — the EK-G645 has both, plus total-RMS combined mode.

4. CAT Rating Without Verification

The IEC 61010 sticker must be backed by a third-party test report. Many brands print the rating without test backing — EK ships TÜV reports with every EK-G645.

5. Battery Life Under Test vs Standby

  • Standby: irrelevant marketing number.
  • Continuous test: the real number — EK-G645 = 200 hours on AAA × 2.

6. Comparison Table to Build Yourself

  1. Make: which factory really built it (OEM vs branded).
  2. Sensor type: CT (AC only) vs Hall (AC+DC).
  3. Resolution at 100 A: counts on display.
  4. Bandwidth -3 dB point.
  5. Calibration cert authority.
  6. Warranty terms in writing.

EK Recommendation

Run the framework above on the EK-G645 and any candidate. EK ships a comparison-test data sheet on request — talk to EK service teams.