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I have bought a cheap but neat Uni-T UT61E multimeter, which only has one display as most multimeters. For 40 Euro's I cant complain. It's on the way to me.

Q.1 If I would like to measure both Voltage and Current, do I have to buy another multimeter? Are there mutlimeters that measure both Voltage and Current in two displays with multiple wires attached to the meter? Have searched but haven't found any hand-multimeter.

Q.2 I would like to put a very tiny voltage/current multimeter lcd on my batery pack so that I can check the volage there (without using my big multimeters) on travels. Any advice on how/where I can find such things? So far I only found this which is a self-build kit:
Do you have better advice and/or know any existing final products that are calibrated and working okay?

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http://www.electronics-diy.com/store.php?sel=kits&sub=pic_voltmeters

My new big mutlimeter on its way, with which I guesse I cant view voltage and current simultaneously:

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  • \$\begingroup\$ It looks like you're measuring currents larger than ~50mA, but still good to know: meter burden voltage makes low current measurements inaccurate in most multimeters, even really good ones. This can be fixed by using a low burden current shunt and calculating I=V/R. \$\endgroup\$ – tyblu Jan 23 '11 at 22:23
  • \$\begingroup\$ I wonder what was your solution to this problem as I am having the exact same one. I also thought to use two multimeters, one for current and the other for voltage (DC), but I am trying to find something that measures it at the same time. \$\endgroup\$ – user33321 Nov 26 '13 at 17:08
  • \$\begingroup\$ This is not an answer to the question and should be posed as a comment to the original posting. \$\endgroup\$ – Adam Lawrence Nov 26 '13 at 17:24
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Q1. They do exist, but they are (much) more expensive. In most cases you can measure a fixed battery voltage and continue to assume that voltage while measuring current. Or, you can buy a meter with a dual display, but those typically aren't cheap. Most dual display meters though can't do everything you need - for example, they can only measure voltage and frequency at the same time. I'd suggest what you do instead is keep the nice meter for accurately measuring most things but buy one of the cheapie Mastech £3 meters to measure the second quantity. They actually do pretty well, most within 0.5% accuracy. And it's no big deal if you damage one.

Q2. I've heard good reviews from this one, designed for model aircraft.

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To anwer your first question:

If you want to measure both current and voltage at the same time, you're doing a power measurement. A typical multimeter has no support for that. To do accurate power measurements, your best bet is to use 2 multimeters at the same time.

If you use 1 multimeter and swap V/I in 2 tests, you may get a little error due to the internal resistance of the multimeter in the Amp range. That might lower the voltage on your load, which may increase current depending on the type of load (switching supplies draw more current with lower input voltages).

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You do not need to measure voltage and current in Your loader simultaneously. They do not change rapidly in Your loader/battery set. You can simply measure Voltage, then current. By me, it is better to buy good quality Charger and batteries, than carrying multimeter with You.

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  • \$\begingroup\$ This is a very old question, and subsequently a very old answer, although for some reason it was on the queue. Regardless, this answer doesn't really seek to answer the question, but rather comment a different approach. \$\endgroup\$ – Funkyguy Sep 30 '15 at 18:25
  • \$\begingroup\$ @Funkyguy The late answers review queue was just changed. \$\endgroup\$ – Null Sep 30 '15 at 18:31
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I often just use two or more multi meters to measure voltage and current simultaneously. I just note the results down by hand periodically, and calculate a rough figure for power draw over time. For more professional purposes, you can get data logging equipment such as Trendeca that can simultaneously log voltage, current, and a whole host of other parameters. This type of equipment is expensive, but produces better results than I can get by hand.

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