Measuring Current In Situ

[meeshu]

Anyone know of an instrument that will measure current flow in (very short) wires (and through components) in-situ? That is, measuring current flow without having to wire in an ammeter (or multimeter) into the circuit!?

Oscilloscpes not allowed (a bit too expensive)!

I know there are clamp meters that measure current, but these tend to be more for heavy current measurements (40A, 400A, 1000A). Also the clamp jaws tend to be too big, and therefore they would not be suitable for measuring current through very small wires/components.

So is there some sort of "mini" clamp meter or equivalent instrument available?

 

[Fallingwater]

I've seen small clamp meters with hall effect sensors that can measure flow in small DC circuits, but I really have no idea where you could find them and how much they cost.
Oh, and if you happen to find one, let me know - I want one too

 

[meeshu]

So far I have found basically two types of "clamp meters".

One type is here. With clones here, and here.

Advantage of this type of meter is that (DC current) measurement is from 1mA to 100A (good range)! More than adequate for measurement of current in electronic and small electrical circuits.

Priced around $160 (can be found for less), so it's not (too) expensive.

Disadvantage is that the jaws are still a bit too big to fit in tightly spaced circuits. In my case, I want to take measurements in a space no wider than around 5 mm; and as the jaws are approximately 13 mm thick, they won't fit into the space!

The other type of clamp meter is here.

Advantage is that its jaws seem to be smaller than the above, so it may be possible to use this meter in my case (with only 5 mm gap to access circuit).

Disadvantages are - (DC) current range limited to 0 ~ 20.99 mA, and 21 ~ 99.99 mA. So this meter can't be used for high current draw circuits. Also, it is priced around $395 (can be found a bit cheaper), which is getting quite expensive!!

In my case, this meter may be suitable as I only want to measure around 20 ~ 50 mA. But, it is too expensive, and its limited current range does not make it suitable for future measurements with currents in excess of 100 mA.

Any other possible meters? Anyone?

 

[Wok]

http://www.bkprecision.com/www/np_specs.asp?m=316

May be useful.....see you found it

 

[paulr]

I thought clamp meters were AC-only because they measure the induced magnetic field from the AC.

 

[DM51]

See post #10 onwards in this thread.

 

[meeshu]

Measurement of DC is enabled by use of "Hall effect" sensors, I believe. DC measurement by use of clamp meters is now becoming common.

Thanks for the links.

Although the Sears clamp meter may be suitable for most situations, in my case, the meter jaws are too big and they won't fit into the confined space within a light I have here.

The AEMC microprobes here, appear to be small enough to fit in small/tight spaces. However, these cost around $600! Far too expensive! So they are not really an option, unfortunately.