I promised this ages ago both here and to my friends at Agilent. I apologize for the crappy quality video. My main P+S is dead at the moment and my phone sucks ass at photos and video, but it's all I have.
The U1211A is a clamp meter, which means it's intended user is most likely an electrician or technician. It's the cheapest of the Agilent clamp meters and the most limited, but also has the largest jaw size which comes in handy when measuring current on large services where the feeders are paralleled into lugs.
The basics:
AC current up to 1000A
AC or DC voltage up to 1000V
Resistance up to 4000 Ohms
Continuity
Diode and Capacitor checks
Build:
It's a friggin tank, as my other recent thread proves. I think to break it you would have to subject it to serious abuse that it wouldn't be exposed to in normal use (heavy mechanical force). The guts survived the 80 km/h toss from my hood onto asphalt, so no worries there.
Accuracy:
The accuracy is very good for both volts and amps which is what I mostly use it for. AC voltage accuracy compared to my U1272A runs around 0.5%. I don't generally use it for DC volts, so no comparison available. It can't read voltage on electronic 12V lighting transformers accurately, but it's only designed to read up to 400 Hz. It's designed to work between -10 and 50 Celsius, with storage temps between -20 and 60 Celsius. I've never had it give me wonky readings in extreme weather and I've never had issues with the LCD becoming unreadable in the cold. Overall, I trust the readings I get from it.
Features:
- TrueRMS. You can't live without that nowadays.
- It has a dual display, but the secondary readout is only for frequency. In order to fit that, they cut back the size of the analog bar graph readout which IMHO makes it too small to be useful.
- 1 ms inrush function. Nice

- Frequency measurement up to 999.9 kHz. Ok, but why can't I read voltages above 400 Hz in that case?

- Min/Max/Average readings
- CAT III 1000V/CAT IV 600V\
- Null function
Useability:
- It's large, which is a plus when clamping around large conductors or in heavy gloves, but a problem when working in tight spaces.
- The resistance range is ridiculous. Most electricians are only going to carry one meter in until they need more, so you expect it to cover most bases. The 4000 Ohm limit doesn't cut it if you have to check floor heat sensors or other high resistance components.
- Backlight and LCD is decent, but not up to the same standard as the one on my 1272.
- Accuracy is excellent, but speed is horrendous for both amps and volts. I've waited over 10 seconds for voltage readings to settle many times. I've tried auto ranging and manual ranging, but it doesn't get faster in either mode. It's slow enough at times that I'm not sure whether I'm getting voltage variances or whether the meter is still settling down on a reading and this makes some measurements very difficult. During recent testing of voltage on a 12V AC lighting transformer I was waiting almost 20 seconds for the reading to settle (I mean, come on... does this thing REALLY need that long to go from 0V to 12.4V?!?). It makes taking Fall of Potential tests almost impossible. In current mode, the wait is mostly for the reading to drop and since it can take a long time, if you're only measuring a small current (ex. 0.5-3A) you don't know whether it's actually seeing 1.4A or whether it's still settling down.
- The peak hold/inrush function works very nicely but you have to know what range you're looking for ahead of time. In the default mode for current readings it's in the 40A range, so even smaller motors can give you an overload indication for the peak reading until you set a higher range.
Overall, for a $250 clamp I'm not really happy. The accuracy is great, but reliability gets questioned in some situations as a result of the painfully slow reading times. The build quality is truly industrial and I hope that Agilent will add a smaller clamp with this kind of build in the future with much faster reading times.
As nice a tool as the 1211 is in some ways, I often wonder whether I should have spent another $100 to get the U1213A or spent less and gotten another brand.
Here's some video of the slow reaction times during measurements of 120V and 24V (nominal) AC.
http://youtu.be/43232S0QZcY