DMM Aneng AN8008

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This is a cheap DMM with all common function.

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It included the DMM, two pair of probes and a manual.

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The standard probes has removable tip covers.

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The probes are rated for 10A, I would not trust that but use some more solid wire for 10A range.

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The other set of probes fells rather low quality, but has some nice functions. They consist of two wires with threads at both ends and a couple of different tips that can be mounted in each end. It is slow to use, but very flexible.

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Here are all the different tips.

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The body of the DMM feels solid, the plastic is rather smooth, i.e. the DMM can easily slide on a surface. The tilting bale is rather flimsy and do not give enough support for pressing buttons and turning the range switch.

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Display

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The above picture shows all the segments on the display.
Notice how u and m symbols are at multiple locations, making it possible to show them just before the unit.
The F, C, MIN, MAX and delta indicators are not used on this meter.

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



Functions

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Buttons:
Rotary switch:

Input

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Measurements
1uF

A look at the capacity measurement waveform.

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Frequency output at highest frequency, it is a +/- 1.6V signal.

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Loading the output to half output voltage shows the impedance is about 2.2kohm

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Reducing the frequency shows that it has a capacitor in the output.

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Tear down

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Four screws and the back could be removed.

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5 more screws and some clips for the front.

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The big black blob (IC2) on the circuit board is the main IC, besides it is a EEPROM (IC1: 24C02A) for calibration and parameters. There are transistors for backlight (Q1) and for the buzzer (Q2), The transistor Q5 is a reference (ICL8069 1.2V), not a transistor. There is also a hidden switch (SW3), I do not know what it do. For the current output (Ohm and capacity ranges) is some protection: a PTC (PTC1) and two transistors (Q3 & Q4). One 100ohm is used for the uA range, the 1ohm alone can be used for a full mA range in some other similar models.
Besides the battery box is the main input drop resistors (R29:5Mohm & R30:5Mohm). Near the 10A fuse (F1) is the resistors for uA (R23 & R24) these two resistors are protected by F2 and D5 (A probably bidirectional Zener diode).
The two fuses are very short and not a standard size.

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No parts on this side, only the switches and a missing solder for the current shunt it is only soldered on the other side.
Notice the input is marked mA, not uA.

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Conclusion

The meter is easily within the specified tolerances (Except 10A) and it has lot of functions and ranges, but the CAT rating is fake.

This is a small DMM in size, but has most of the expected functions in a universal DMM. It has a hole in the current range, it can measure currents in that range, but with fairly low precision, instead it has very low burden voltage in the mA range and low precision at high current.

I do not like the small fuse size, they cannot break high voltage or high current and they can be hard to source locally (They can be found on Ebay). The current range on the voltage input is also a bad idea.

The 9999 count secures the best possible resolution for 4 digits.

I will call it good DMM for hobby use, but keep it away from anything with mains voltage and lots of amps.





Notes

This meter exist with many different names on it and small variations in functions.

How do I review a DMM