Test/review of DMM Aneng AN870

EDC Gear for Flashlight Carriers
1

DMM Aneng AN870







The brand Aneng has been on a lot of meters recently (in 2017), most of them very capable meters at very good prices, do this trend continue with this meter?







I got the meter in the usual black plastic bag with some protective wrapping around the pouch.







The pouch.







It included the DMM, a pair of normal probes, a pair of DIY probes, a thermocoupler and a manual.









The probes has removable tip covers, the tip and tip cover has the usual CAT markings, but there is not much markings on the probe them.







The shrouded plug is the slightly short variety.







The DIY probe set, it is a bit low in quality and some work may be required to screw the tips in (One of the banana plugs was missing threads).







A end without any tip.















The DIY probes with the different tips.











The thermocoupler is the probe type, this is useful for stuff where you want to stick the thermocoupler in, but not very good at measuring surface temperatures.









The range switch is a bit difficult to use single handed when meter is on the tilting bale, it slides around.











































Display







The above picture shows all the segments on the display, not all are used by this meter.

Notice the small 2, 20,200, 2000 digits, they are used to show the selected range.

The backlight has a hotspot at the minus sign, the rest of the display is fairly even illuminated.







Typical display during usage, it will show the number and what measurement is selected.







The NCV is the usual bars and the buzzer.







Functions







Buttons:

  • Range: Will disable auto range and change range, hold down to activate auto range.

  • Rel: Shows values relative to current value, will also select manual range. Press again to disable.

  • Max/min: Starts recording maximum and minimum value, press to select between max/min.

  • Hz % (Blue): Shows frequency and duty cycle in AC ranges.

  • Select (Yellow): Select the ranges printed with yellow and between C°/F°

  • Hold: Freezes the display, hold down for backlight.

REL and MAX/MIN will change to manual range and return to auto range when disabled.



Rotary switch:

  • Off: Meter is turned off

  • VAC: Show AC voltage, using the blue button frequency and duty cycle can be selected.

  • VDC: Show DC voltage.

  • mV: Show DC or AC mV and temperature. In AC the blue button will show frequency and duty cycle.

  • : Resistance, continuity, diode and capacity.

  • Hz: Logical frequency and duty cycle (Use blue button to change between them).

  • A: Current AC and DC. In AC the blue button will show frequency and duty cycle.

  • mA: Current AC and DC. In AC the blue button will show frequency and duty cycle. Watch out for burden voltage.

  • uA: Current AC and DC. In AC the blue button will show frequency and duty cycle.

  • NCV: Non-contact voltage or electric field detection.


Input


  • 20A: High current, it can only withstand 20+ ampere for a short time due to heat (Fuse is 20A).

  • mAuA: The lower current ranges, the selector switch will change between two different shunts (Fuse is 200mA).

  • CON: The common terminal for all ranges.

  • xxx: All other ranges.




Measurements

  • Volt and frequency

    • At 100mVrms input frequency range is from 1Hz to 5.6MHz

    • At 2Vrms input frequency range can be stretched to 20MHz

    • Max/min needs about 360ms to capture a voltage with repeating pulses.

    • 1 VAC is 5% down at 2.1kHz (RMS will not work at the frequency).

    • Frequency counter and duty cycle can only be selected in AC ranges.

    • Frequency input requires a zero crossing.

    • Duty cycle works from 2% to above 99% at 100kHz with 1Vpp, precision is within 0.2 (Mostly 0.1).

    • Input impedance is 10…11Mohm on DC and AC

    • mV range is high impedance for DC up to around 1.5 volt where it drops to a few kOhm. AC is similar, but capped at 10Mohm

    • Frequency input is 10Mohm up to around 2 volt, then the protection clamps to 2kOhm

  • Current

    • Frequency counter and duty cycle can only be selected in AC ranges.

    • 200mA current is protected by a 0.2A/250V 6x30mm fuse.

    • 20A current is protected by a 20A/250V 6x30mm fuse.

    • The 20A range has an audible alarm at 10A.

  • Ohm, Continuity, diode and capacity

    • Ohm needs about 2.8s to measure 100ohm

    • Ohm is 1V open and 0.37mA shorted

    • Continuity is fast (About 20ms).

    • Continuity beeps when resistance is below 50ohm.

    • Continuity is 1V open and 0.37mA shorted

    • Diode range uses 3.2V, max. display is 3.000V at 0.13mA, max. current is 1.6mA shorted

    • 10uF takes about 4.5 seconds to measure.

    • 70000uF takes about 9 seconds to measure.

    • Overload protection is not rated

  • Miscellaneous

    • Current consumption of meter is 1.2 to 2mA depending on range (AC adds 0.4mA), with backlight it is up to 9mA.

    • Meter works down to 2.2V where it turns off, battery symbol show at 2.4V.

    • Reading do not change with battery voltage.

    • Backlight only works down to about 2.6V where it is fairly dim.

    • The meter usual need a couple of display update to reach the final value.

    • Viewing angle is good.

    • Display updates around 3 times/sec

    • Backlight will automatic turn off in about 120 seconds.

    • Will automatic turn power off in about 15 minutes.

    • Standard probes cannot be pushed fully down they are a bit loose.

    • Weight is 374g without accessories, but with rubber sleeve and batteries.

    • Size is 180 x 89 x 44mm with rubber sleeve.

  • Probes

    • Probe resistance 33mOhm for one.

    • Probe wire is soft and 78cm long.

    • DIY probes resistance is 51mOhm

    • DIY probe wire is 86cm long



A look at the capacity measurement waveform.



Frequency input resistance depends on input voltage. This is fairly similar to mVAC input.



The meter cannot be used at 20A, the reading will drift (At 19A 5% drift in 13 seconds). At 10A the drift is still present, but much slower.
AC input cannot handle large DC offset.



Tear down



Four screws and the back could be removed.




The circuit board is shaped to follow the box.




6 small screws and the circuit board was nearly loose, I had to unsolder the backlight to get it out.



The display and backlight are still in the box-





The 20A shunt (R33: 0.01ohm) is very small, it is no wonder it cannot handle 20A without getting hot, or is it the copper trace. Sense is connected to the uA shunt (R23: 99ohm). The mA shunt (R24: 1ohm) is next to the uA shunt. On opposite side of the circuit board is the mAuA fuse and a transient diode (D5: 6V8) to protect the resistors until the fuse blows.
The 10Mohm input is done with two resistors (R29 & R30: 2x5Mohm) and goes directly to the chip. For the ohm, capacity, frequency and mV input the input goes to a PTC (PTC1: 1.5Kohm) and a transistor pair (Q3 & Q4).
The multimeter IC (IC3) has a external EEPROM (IC1: P24C02A) for calibration and functions, there is also a reference IC (Q5: ICL8069). There is a transistor for the buzzer (Q2) and for the backlight (Q1).
At the top of the circuit board is a trace as antenna for the NCV, it has some high ohmic resistors (R37, R38, R39: 3x20Mohm) as load.









This side of the circuit board only has contact pads for the switches, range selector and LCD display. The 20A trace is also present in this side, but it is not enough for 20A.




Conclusion

The meter is within the specified tolerances (Except 20A range) and it has lot of functions and ranges, but the CAT rating is fake.
It is a fairly good meter to use on the bench.



Notes

The multimeter was supplied by Banggood for review.

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2

Thanks for the review.

20,000 count - nice!

Given that it’s about the same price as Uni-T UT61E, which one would you choose? Is the accuracy of this AN870 any better than UT61E?

I still like the fact that you can do logging with UT61E.

3

That is difficult to answer.

UT61E has a problem with burden voltage in uAmA range, it has computer interface, it has peak function, it has bargraph. The A shunt is physical larger, i.e. it is probably slightly more stable around 10A. It is filled with trimpots, this means you can adjust it yourself, but the risk it is going out of adjustment is also greater. The diode test do not show voltage for white leds.
For accuracy it varies by range (Check specifications), just because my test meter is perfectly calibrated or not, is no guarantee how the next meter is calibrated. The multimeters with a EEPROM for calibration is often very well calibrated, because it can be done automatic.

Maybe I ought to get a new UT61E (It may have changed over the years) and run it through my new testing.

4

That would be great if you could.

Also, I’m sure you know, there are actually two versions of this DMM: an international version (which I believe you reviewed a long time ago), and a Euro version that has better quality internals and carries some European safety certifications. I believe this is the Euro version - you can see the TUV logo, and quite a bit more expensive than the non-Euro one.

5

A helpful review, thank you :slight_smile:

How do you find out the voltage rating of the fuses? I couldn’t see anything printed on them, so I was wondering if there’s some special test you do?

6

Thanks for the review HKJ.

Input protection is lacking on this meter and it looks like the UT61E is built better then this meter.

How do the screen compare to each other on this meter and the UT61E?

7

I would probably buy it from China, i.e. the version with the low protection.

It is on the circuit board.
Generally I check manual, circuit board and the fuse, the worst rating is the one I use

AN870 has one PTC somewhere on the circuit board, UT61E has two PTC’s place at the input, neither is perfect, but will usual handle 230VAC.


They look a bit sharper in real life, I got some glare from the light. I like the big digits on the AN870. Also remember that UT61E do not have background light and AN870 has a useful one.

Remember my UT61E is some years old.

8

That’s probably the most reasonable choice. I don’t think too many people are going to buy the Euro version - there are possibly better DMMs out there at that price.

9

Hello! I’m from India. I’ve decided to buy a multimeter. After seeing a lot of multimeters in online, I’ve decided to buy an Aneng Multimeter. But there was also a problem. First I choosed ‘Aneng an8009’ multimeter. But after some day, ‘Aneng an870’ model attracts me. But the Display of an870 is not so good as an8009 where as an870 has more accuracy etc. than an8009 (I think so…).
Again the two multimeters’ CAT rating is not true (according to reviews in internet and you also said this). Well… I’m a electronics hobbyist and I’ve not needed to work with high voltage continuously. Please tell me, whether these multimeters can not be worked for sometimes, not continuously.

Please tell me. I’m really very confused about this feature. and also about the Display of ‘Aneng an870’. Is the backlight better than an8009 or not?

Please tell me. I’ll waiting for your answer.
my email id: diptangshu.das100@gmail.com

10

I will recommend you use this table to do a fast comparison of the meters:
https://lygte-info.dk/info/DMMReviews.html

You can also use the schema’s I have made.

Both meters do fairly well, but I prefer 6 current ranges, the smaller meters only has four.
These meters are cheaply made, this means they will not last as long as the more expensive meters, but they may still last many years for occasionally use.

11

Hello Sir, I’ve two questions…

  1. Why some automotive multimeter takes too long time to measure Resistance (like Aneng Multimeters, HY-19e multimeter etc.) where as some of them show the result instantly (e.g. Metravi Multimeters) and it is correct also. Why this occurs?
  2. How you check whether the CAT Rating in a DMM is fake or real? I mean, can I check it myself?
    Please tell me.
    my email id: diptangshu.das1000@gmail.com
12

This depends on the chip used in the multimeter and how it is programmed. A reason to be slow is to suppress more interference (Some meters use better algorithms instead)

I cannot tell if a CAT rating is real, except by looking for a independent approval and check the public list at that agency.

On some meters it is easy to see a false rating, today the fuses must be rated for at least the same voltage as the rest of the meter and be designed to interrupt high current (i.e. sand filled ceramic fuses) (Older CAT ratings allowed different ratings for current and voltage input).

Ohm and a couple of other ranges need protection from high voltage, this is usual done with two PTC’s or one PTC and a resistor, in addition to a transistor pair or some diodes. If this circuit is missing it can hardly be CAT rated for higher voltage.
Many cheap meters has a single PTC and a transistor pair for protection, this may work up to 300V, but not at higher voltage. They also have the input voltage across a single SMD resistor, this would fail a CAT rating.