Clamp meter
Klein Tools CL800
True-RMS auto-ranging clamp meter that reads current by clamping around a single conductor — no circuit interruption.
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Best for
Finding out what a circuit or appliance is actually drawing
Specifications
| AC current | Up to 600 A via clamp |
|---|---|
| Measurement | True-RMS |
| Safety rating | CAT III 600 V |
Specifications as published by Klein Tools. Confirm against the current spec sheet before buying — manufacturers revise models without renaming them.
What's good
- The only practical way to measure a real load at home without breaking the circuit
- True-RMS handles motor and inverter loads correctly
- Also works as a standard multimeter with the included leads
What's not
- Jaw has to fit around one conductor — crowded panels make this awkward
- Clamping a whole cable reads zero, which confuses first-time users
Our verdict
This is the tool that turns nameplate guesses into real numbers. Sizing a generator, checking whether a circuit is near its limit, or working out why one breaker keeps tripping all become measurements instead of arguments. Feed the reading straight into the home electrical load calculator.
Compare with the alternatives
- Klein Tools NCVT-3P — confirming a circuit is dead before you open a device or box
- Fluke 1AC-A1-II VoltAlert — a simple, rugged live/dead check on 120 v and 240 v branch circuits
- Sperry Instruments GFI6302 — checking every outlet in a house quickly for miswiring
- Klein Tools RT250 — diagnosing voltage drop or a flaky circuit, not just wiring order
- Klein Tools ET310 — labeling a panel without two people and a lot of shouting
- Klein Tools MM400 — a first multimeter that will not be outgrown for home work
- Fluke 117 — anyone who will do this more than once a year
- Fluke 323 — measuring current in a tight, densely packed load center