Klarus MiX6 1x AAA

Often a reading of 0.015A would be suspect, due to specifications. I.e. a meter is specified as x%+y and the y is an absolute error, i.e. if y is 10 the last digit can not be trusted.

But when measuring current you also have to think about the "burden voltage", i.e. the voltage drop in the meter, especially when measuring something that runs at 1.5 volt (I did not find the specification in the manual for your meter).

Look at this curve from my review:

At 1.2 volt the current is 15 mA, but if you looses 0.2 volt in the meter the current will be 22 mA. Also remember that the current will depend on the battery voltage!

thanks a lot! Well, the specs for the "0.015A" reading are stated as "0.015 A ±(1.2%+50)" on Low mode with an Eneloop cell@1.40V. This translates as:

max: 0.015 *1.012 + 0.050 = 0.06518 A=65.18 mA

min: 0.015 *0.988 - 0.050 = -0.03518 A= -35.18 mA

So the actual value from the "A"-setting reading is in the range -35.18mA < X < 65.18mA. Wow, that is not very accurate!

And for the "26.15mA" reading it's "26.15 mA ±(0.5%+10)":

max: 26.15 * 1.005 + 0.10 =26.38075 mA

min: 26.15 * 0.995 - 0.10 = 25.91925 mA

So the actual value from the "mA"-setting reading is between 25.92mA < X < 26.38mA. Now that's a lot better!

Voltage drop in the meter? You mean, I = U / (R1 + R2)

and Udrop = R2 * U / (R1 + R2), so i would have to measure the resistance of the torch ("R1"), and calculate I = U / R1, instead of directly measuring the I? Wouh.

Anyway, for the graphs and data you use an external power supply, dont you? Hehe.. that's in contrast to your DMM usage tutorial where you use 2 DMM's and the original battery in the photos (afaik).

I am just trying to reproduce your measured "15mA" from your table.. so for low amperage ranges the "mA"-setting should give better results.. but i cannot reproduce the 0.015A until i use the "A"-setting.

So which DMM setting do you recommend for Low-mode: the "A"-setting or the "mA"-setting? Thanks!!

Generally I recommend that you stay below 1/10 of the full range, this will usual mean you have to use manual range select. On most meters this will mean less than 0.1 volt drop over the meter and you do retain a acceptable precision.

I you have two meters, you can use one meter to measure voltage drop over the other meter and also to measure how many volt that reach the light. Especially at 1.5 volt you really have to watch out for resistance in every thing (meters, cables, probes, etc.), a 0.1 volt drop is very significant.

You do not really need a specific meter, you just need to use it the best way and know what it is you measure.

For my curves I uses a computer controlled power supply and a voltmeter connected (mostly) directly to the light.

Thanks HKJ!

i've completed my tailcap readings and updated the OP. My measurements with the "A"-setting are the same as yours. Out of curiosity i also included the "mA"-readings in the table -- they can be safely ignored; from the behavior of the light (brightness levels, modes) i could tell that the DMM consumes too much voltage at the "mA"-setting so that the mA-readings are all off.

Something interesting i found out: The MiX6 draws much more current from a NiMH cell (e.g. Varta Ready2Use) than from an original Eneloop cell, on High-modes. it also means that MiX6 regulates the High-mode brightness on an Eneloop cell but does not on a typical NiMH cell (nor on an Alkaline cell).

The only recommendable cell type for the MiX6 is Eneloop then!!

At some later point when i am bored again i will do several testruns to measure burn times on Eneloops.

I just did run time on a mix6(27 lm) and got 5 hr 35 min with a imedion 950. Yhe eneloop gave me 4. 5 HRS. Big difference! The IM cost the same as EN.

keith

good work kreisler but hell is possible that need half day to read any of your review? xD

and I'm sure, it will grown at least of another 1/4 xD

@marcl your is high-power spam coz when we all mark dudunice as spammer your post will remain... xD

Thanks HKJ, the article and product description explain in detail that multimeters in the mA and uA range cannot measure the current accurately in low voltage circuits unless a product called uCurrent is placed in series (or parallel?):

uCurrent - A Professional Precision Current Adapter for Multimeters

Basically it means that miliamperage readings in 1.5V voltage circuits are very inaccurate without the 59.95US$ adapter. And obviously my readings in the mA-setting are all wrong. Even if the current is as tiny as 15mA, i am advised to use the 10A-setting of the DMM.

HKJ, maybe you could point to this topic with more poignancy in your article, so that flashaholics avoid the mA/uA-setting of their DMM in any case!

David is a good source and is uCurrent adapter can be very useful (I have it). But in many cases you can easily get around the problem.

The idea is to never use more than 1/10 the range on the DMM, i.e. if the meter has a max reading of 1999, never go above 0199. On auto ranging meters you must select manual range to do this!

Most meters has a voltage drop between 0.3 and 1 volt at full range (Cheap unfused DMM's can be better) and this "trick" will reduce the voltage drop to 0.1 volt or lower. This is not perfect, but useful in most cases.

You also has to watch out for the few meters with more than 1 volt voltage drop (A Fluke is no guarantee for low voltage drop, I believe the worst meter I have seen was a Fluke).


Maybe it would be a good idea to explain it a bit more in my DMM guide, but it will probably not be this week (My main computer crashed last week and even a reinstall did not get it working. I hope a new computer will arrive later this week).

Good luck with getting a new computer! Since your webpage is meant to be a guide, i would welcome a bit more explanation (or links to Dave's pages), e.g. with a clear hands-on example... [quote=HKJ] The idea is to never use more than 1/10 the range on the DMM, i.e. if the meter has a max reading of 1999, never go above 0199. On auto ranging meters you must select manual range to do this! [/quote] ...This i wouldnt fully understand because it is no clear example with step-by-step guide ;)

Hehe.

I am not sure if i have understood the above quote (contentwise) correctly .. so let me try to re-explain your quote in my own words from my understanding. I would certainly understand a text such as this:

Maybe my text is wrong contentwise but it is an example of a text which can serve as clear guide, because it is detailed and contains 2 leading examples (DT830B vs. UT61E) with several sub-examples (37.48mA; 0.015A; 0.008A). And anyone who is new to DMM's would understand the logics of the measurement strategy. Some people/authors shun such detailed texts and prefer a concise style of prose but imho guides are not written to please the writer but to serve a concrete purpose: to be clear and helpful to the reader.

And that includes any kind of half dumb-a$$ed reader, even kiddos such as dinoboy

I do not like that kind of examples, there are way to much text and to few photos.

As for you first example. The problem is that your meter is missing a range between 200 mA and 10 A (As are most meters). There are two solutions to that, only is used the 10A range and use the digits you can get (The DMM tolerance will often spoil that), the other is to get a meter with 4999 or 5999 display.

In you second example I am not sure if you are a a factor 10 off? In the 200mA range you can measure up to 20mA without worrying about voltage drop. This 1/10 rule is not a on/off thing, it is much more gradual and depends very much on the meters. Using 1/10 is a good rule of thumb, but if you know the precise specifications for the DMM, you will know when to use it and when it is not necessary and when the uCurrent is the best solution.

Having a selection of different DMM's can be useful, because not all meters are good for everything, my four best DMM's all has different abilities. For some measurements all will do, for other measurements I need a specific DMM.

When you only have one DMM, you need to find the best way to measurements with that. Maybe using an external resistor for these measurement, a 0.1 ohm would work very fine, you would get rid of most wire resistance and have a resolution of 0.1 mA with a insignificant voltage drop at 100mA.

damn kreisler I advised you to buy a 5$ multimeter instead of that... xD

i am not going to buy the 59.95$ adapter... xD

well, i still dont fully understand the “1/10”-rule in the first place (because of missing elaborate explanations accompanied with examples and i am looking forward to your revised guide), so i am sure that contentwise my quote is wrong in many ways. i was writing off the top of my head and only guessing what you were meaning with the 1/10 rule of thumb. i still dont know if most of Example1 is factually correct (e.g. the 22.00mA limit).

with a single sentence, no wiring scheme (circuit diagram), no math. equations. nobody could expect that everybody understands what the strategy/idea of your plan is

You example is mostly correct, but you take the 22 mA as a hard limit and that is wrong. The measurement error will slowly increase when current goes up, the 22mA (or 1/10) is a rule of thumb and not some magic limit.

The 61E looks like a very good meter for the money and I did order one to play with. At the current time it is at the custom office (They do probably not believe the price and are going to ask me for some documentation), but I expect to get it sometime next week and then I will be able to say much more about the burden voltage.

Would a picture from my DMM guide help (You can find the math in the guide):

Ahh right right. I had forgotten about that picture and the maths. Was weeks ago when i last read your DMM guide. I think i had skipped that section because i dont possess any resistor (accurate resistors with strict tolerances cost money) nor alligator clips. I will look into buying the things one day..

Oh, you ordered the 61E a while back too? Yes, very well priced with DD discounts (thanks MixoMaxo!! ). The documentation is a joke and i still dont know the functions of the buttons (and application strategy). The PDF is a short manual but not a dedicated user's guide. Maybe you can assess the quality of the DMM.

i will feel happy when HKJ evaluates the 61E to be a great DMM! xD

A 0.1 ohm 1% 1 watt resistor is not that expensive. There is not reason for better than 1% when measuring current drain in flashlights, both the variations between lights and between batteries will be larger.

The documentation is as good as it gets for cheap meters (Or did you not get the full manual). Some more specifications would have been nice. When you are used to DMM's the buttons are easy enough to figure out. The yellow and blue is used to select the alternate ranges that has the same color printing at the switch. The HOLD can be used to freeze the reading, I seldom uses that. The RANGE is for manual range. The REL set the current value as zero and shows all values relative to that value. When PEEK is pressed the meter will collect max and min values.

I will probably not do that, but it can be great for the money.

I do not plan to do a full review or anything like that, but I will do a fast check and post my opinion about the meter.

That did not work out, the result is less than great and the problem is the current ranges.

I did a full review of it here.

I still feel happy nonetheless .. happy out of gratitude for your reviewing work!

Knowing the truth about one's product is more helpful than believing in something wrong

THANKS SO MUCH!!

EDIT: i've expanded the bottom section of the OP with a mod. the mod was inspired by the genial construction of the DQG Tiny III which works with no rear spring installed. if you find the mod useful, please make me happy!!

(huh?? lol myself)

Really enjoyed reading this. Amazed at how much I am learning from this site.

an observation from today's DD shipments, 2 baskets full of MiX6's were dispatched (and a day later even more), not bad! i am wondering if the buyers were aware that the real Ti's are sold off (sold out) in DD's inventory and that only the SS's are shipped.

The webpage isnt 100% clear, it still says things such as "www.dinodirect.com/flashlight-klarus-mi-titanium-version-edc-aaa.html" and "TC4" .. but that's no more bait'n switch ;)