Decent Clamp on Ammeter with DC Amps

superheat6k

superheat6k

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After buying a £120 RS Pro clamp on meter, which was defective and then the replacement delivered also defective with the same issue (unstable display on AC voltages making it a lethal device !), I then bought this Uni-T UT210E Clamp on Ammeter / Multi meter from Amazon for use for my work.

However, I have just found it on Ebay for less than £30. It is an excellent bit of kit. It also measures DC Amps from the clamp (not in-circuit measurement) and has a voltage presence indicator on the tip of the jaws too. It is also fairly compact. I already have two Uni-T multimeters and know these are reasonable meters.

I am now buying a second one for the boat.

https://www.ebay.co.uk/itm/UNI-T-UT...133798?hash=item239e445566:g:0JkAAOSw5utaaaWL
 
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DC Clamp meters are a waste of time, useless. They use a hall effect sensor to detect the strength of the magentic field around the cable, so are very much affected by the earths magentic field. Try putting it on a cable with a known steady current, and then sail around a 360 degree circle ... the reading will be all over the place.
 
I bought a cheap DC clamp meter from RS, can't remember the brand. I think it was about £40 around 5 years ago. It's very useful, and reasonably accurate. It has saved its cost. You do have to take reasonable care with stray magnetic fields to get the very best out of it, but most troubleshooting you don't care if the alternator is putting out 30A or 31.72A, 'about 30A' tells you it's working. When a starter motor doesn't crank very well, it's a good way of knowing whether the current is actually flowing, and near enough how much, to rule out a dead starter motor. All without undoing anything.
 
rszemeti said:
DC Clamp meters are a waste of time, useless. They use a hall effect sensor to detect the strength of the magentic field around the cable, so are very much affected by the earths magentic field. Try putting it on a cable with a known steady current, and then sail around a 360 degree circle ... the reading will be all over the place.
Click to expand...

Rubbish. For the TECPEL meter I have anyway, calibrate right next to the wire then clamp over it - will be consistently within a few hundred mA compared to an ammeter. Or several to confirm.
 
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GHA said:
Rubbish. For the UniT DCTECPEL meter I have anyway, calibrate right next to the wire then clamp over it - will be consistently within a few hundred mA compared to an ammeter. Or several to confirm.
Click to expand...

Agree - I have the same meter linked in the OP, and when I got it I set up a dummy load and compared the clamp to a standard ammeter in series. Sure neither was calibrated for scientific measurement, but they agreed remarkably closely.

My only real complaints with it are firstly that the voltage mode defaults to AC (which I never need) instead of DC, so I have to press the "Select" button every time to change it. And secondly that it's auto-ranging and takes a second or so to decide what range it's going to use, so it's not good for measuring brief pulses or showing exactly when something comes on. I carry a simple test lamp to use instead for these cases.

Pete
 
Interesting, as I assume most will be using this for DC Amps. The cheaper unit is rated 2A/20A/100A for DC and the more expensive from 40A but up to 400A DC. Does this imply you need two onboard! One for the engine and battery bay and one for the electrical panel?
 
PaulRainbow said:
Slightly more money ; https://www.ebay.co.uk/itm/143226829871?ViewItem=&item=143226829871
Click to expand...

I bought one years ago for about £35, so mid-way between this model and cheaper one shown earlier. It looks remarkably like a TENMA model available at that time and has been good value. It has the same freq. measuring feature and all the other features on older TENMA. It has been sufficiently accurate for all the jobs I've done and has always been fairly close to other devices I have fitted or other non-clamp meters. I'm usually only bothered about 0.5 - 40A range and rarely sail in circles whilst measuring.

I'd buy the TENMA model now as I don't think the "re-branded copy" I bought is available now.
 
superheat6k said:
After buying a £120 RS Pro clamp on meter, which was defective and then the replacement delivered also defective with the same issue (unstable display on AC voltages making it a lethal device !), I then bought this Uni-T UT210E Clamp on Ammeter / Multi meter from Amazon for use for my work.

However, I have just found it on Ebay for less than £30. It is an excellent bit of kit. It also measures DC Amps from the clamp (not in-circuit measurement) and has a voltage presence indicator on the tip of the jaws too. It is also fairly compact. I already have two Uni-T multimeters and know these are reasonable meters.

I am now buying a second one for the boat.

https://www.ebay.co.uk/itm/UNI-T-UT...133798?hash=item239e445566:g:0JkAAOSw5utaaaWL
Click to expand...

Agree, bought the same model a few months ago and been very happy with it, worth it at that price.
 
FYI there's some good reading about this meter here: https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/

prv said:
My only real complaints with it are firstly that the voltage mode defaults to AC (which I never need) instead of DC, so I have to press the "Select" button every time to change it.
Click to expand...

This (and many other things) can be easily changed with a cheap eeprom programmer. A quick vid here (based on information from the above linked thread): https://www.youtube.com/watch?v=fX-Fhq9R4uY
 
prv said:
Agree - I have the same meter linked in the OP, and when I got it I set up a dummy load and compared the clamp to a standard ammeter in series. Sure neither was calibrated for scientific measurement, but they agreed remarkably closely.

My only real complaints with it are firstly that the voltage mode defaults to AC (which I never need) instead of DC, so I have to press the "Select" button every time to change it. And secondly that it's auto-ranging and takes a second or so to decide what range it's going to use, so it's not good for measuring brief pulses or showing exactly when something comes on. I carry a simple test lamp to use instead for these cases.

Pete
Click to expand...

exactly my complaints Pete!

I have the same, bought a second for a friend. Very useful, always zero on the spot before clamping the cable.

one WARNING though!
Mine started playing up after a year bashing about in the bilges and all around the boat. Had to take it apart and I noticed that the rotary thing wasn't doing decent contact and on touching and pushing it vertically to the rotation axis I'd loose settings and/or change mode. Ended up with a bodge with some thin film plastic on the axle keeping it firm and not letting it wobble.
Works fine, but do take care and don't bash it too much :rolleyes:

V.
 
rszemeti said:
DC Clamp meters are a waste of time, useless. They use a hall effect sensor to detect the strength of the magentic field around the cable, so are very much affected by the earths magentic field. Try putting it on a cable with a known steady current, and then sail around a 360 degree circle ... the reading will be all over the place.
Click to expand...

Meh. As long as you zero them and don't move them in use they work just fine.

I have the cheap one - bought after a recommendation here - and it has been very useful.
 
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Looking at getting on of these devices.

CPC lists what seem to equivalents to both of these at about the same price. Is there any advantage in the lower range one over the one with frequency? Perhaps finer resolution on the 2A/20A ranges?

I looks same as OP:
TENMA 72-2985 @£37.38

This is as per PaulRainbows link:
TENMA 72-7224 @£36.32
 
rszemeti said:
DC Clamp meters are a waste of time, useless. They use a hall effect sensor to detect the strength of the magentic field around the cable, so are very much affected by the earths magentic field. Try putting it on a cable with a known steady current, and then sail around a 360 degree circle ... the reading will be all over the place.
Click to expand...

Edit: I've replied already but can't find a delete button in the new forums.
 
I have a clamp meter, which gets used for such thing as bikes which won't start.
I find I use the 'max hold' function to get some idea of what the starter current peaks at, it's a quick diagnosis between battery and starter motor.
It's a function I'd miss which neither of those meters has.
 
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