Accessory current clamps can expand a multimeter’s flexibility and measurement capabilities by allowing it to measure up to thousands of amps. The clamp accessory reduces the actual measured current by a fixed ratio. This means that the current maximum is now limited by the clamp instead of the multimeter.

The following discussion focuses on the most common types of current clamps used with digital multimeters (Digital multimeter):

1. AC only with a milliamp output like the Fluke i200, i400, 80i-400, 80i-600A or i800
2. AC/DC with a millivolt output like the Fluke i410 AC/DC Current Clamp AC/DC Current Clamp, i1010 and 80i-110s

Note: This is not a complete user guide. Make sure to read the safety and usage information contained within the clamp’s instruction sheets.

AC clamps: Fluke i200, i400, 80i-400 or i800

The i200, i400, 80i-400, and i800 are current transformer-type clamps that have an output of 1 milliamp ac per amp ac. This is a 1000:1 ratio. Additionally, they also have banana plug connections. However, take note that these clamps do not measure dc current.

To use these clamps with a Fluke Digital multimeter, the meter must have a milliamp input jack. Plug the black output lead into the meter’s common jack and the red output lead into the meter’s milliamp or mA input jack. Set the meter’s function switch to read ac milliamps.

Furthermore, place the clamp jaws around only one conductor of the circuit. Clamping around both the line and neutral conductors (like a line cord) at the same time will cancel the current flow reading. If there is currently flowing in the circuit, the milliamp reading in the display will be the actual current flow in amps.

The reading on the Fluke 87V Industrial Multimeter display (15.86 mA ac) corresponds to a true circuit current of 15.86 amps ac. The reading on the Fluke 289 True-RMS Data Logging Multimeter display (225.32 mA ac) corresponds to a true circuit current of 225.32 amps ac.

AC/DC clamps: Fluke i410 AC/DC Current Clamp AC/DC Current Clamp and i1010

The i410 and i1010 are ac/dc Hall Effect type clamps. That is, they contain Hall Effect sensors, and have internal electronics and a power switch. These clamps have an output of 1 millivolt ac per amp ac for ac current measurements and 1 millivolt dc per amp dc for dc current measurements. Again, these have a 1000:1 turns ratio.

To use these clamps with a Fluke Digital multimeter for best results, the meter should have a millivolt range for either ac or dc voltage depending on the current to be measured. And then, there are ac current measurements. For this to work, plug the black output lead into the meter’s common jack and the red output lead into the meter’s V/? input jack. Set the meter’s function switch to read ac voltage or ac millivolts.

Connections for i410/i1010 clamps with a 289 Digital multimeter

The reading in the Fluke 289 True-RMS Data Logging Multimeter display (7.437 mV ac) corresponds to a true circuit current of 7.437 amps ac.

For dc current measurements, here’s what you have to do. Plug the black output lead into the meter’s common jack and the red output lead into the meter’s V/? input jack. Set the meter’s function switch to read dc millivolts. Turn the clamp on by pressing the green power button.

Here’s what you should do for the most accurate dc measurements. With the jaws closed use the “zero” adjust to zero the displayed reading before clamping around the current to be measured. DC measurements only require zero adjustments. Only one conductor should have clamp jaws wrapped around them. If there is currently flowing in the circuit, the millivolt reading in the display will be the actual current flow in amps.

AC/DC clamps: Fluke 80i-110s

80i-110s is also an ac/dc Hall Effect Type clamp. This is a dual-range clamp with an output of either 10 millivolts or 100 millivolts per amp ac for ac current measurements or 10 millivolts or 100 millivolts per amp dc for dc current measurements. Use the 100 millivolts per amp position for accurate current measurements up to 10 amps and the 10 millivolts per amp position for current measurements exceeding 10 amps but less than 100 amps

initially, this clamp was originally designed for use with an oscilloscope and terminates with a BNC-style connector. To use it with a Digital multimeter, add a PM9081/001 BNC to the dual banana adapter. Therefore, for best results, the Digital multimeter should have a millivolt range for either ac or dc voltage, depending on the current to be measured.

Meanwhile, for ac current measurements, plug the black output connector into the meter’s common jack and the red output connector into the meter’s V/? input jack. Set the meter’s function switch to read AC millivolts or AC voltage. Finally, turn the probe on by sliding the switch from “Off” to the appropriate range position depending on the current.

To know more of our fluke Digital multimeter products, visit our website at https://presidium.ph/product-category/products/fluke-industrial-group-tools/digital-multimeters/