This unit was provided free of charge for non-biased independent review. Unit received inside a dedicated printed box, with English User Manual and a Chinese User Manual.
This item is sold in two colors, red and black. Currently available at AliExpress for a price of about $3 or $4US. Batteries not included (2x AAA 1.5V).
Main Features:
AC 50-60 Hz live circuit detection, non-contact (NCV) or contact (Live Wire) .
Flashlight (White LED)
Screwdriver (Fixed Slotted)
Feature Details:
Live wire (fire wire) test is direct contact of the tip to metal conductor. Capable of approximating AC voltage measurement 12-300V.
NCV is Non-Contact AC Voltage presence 20-1000V AC. Will help find break (broken) live circuit in wire.
Has a LCD Backlit display, Green most of the time then changes briefly to yellow then red on live wire detection.
A bar graph also indicates the relative level of induction detected.
Audible beep, rate of which is dependent on induction level.
Auto Power Off after 3 minutes no-use
Fixed flat-blade screwdriver with removable collar
Pocket clip integrated into no-tool-required battery cover.
Claimed safety rating CE CAT.ll 1000V / CATIV 600V
Now for the review of the actual unit received:
On power-up, by means of a long press of the power button, there is a delay while most of the digits are displayed without backlight. The time takes from 1 second to 10 seconds. Perhaps the unit is calibrating and sometimes needs to wait for stable environment conditions. Not sure if you should hold the unit or set it down somewhere. Owner's manual didn't say - doesn't seem to make a difference either way.
This is sold as "Smart" meter in some literature. I'm sure what smart refers to. There is no individual modes to engage on this unit. One range works for both NCV and Live Wire. Both are to be accomplished with your thumb/finger on the conductor on the side of the unit. Non-contact detection is therefore weaker and less sensitive than metal conductor contact is. After using, I would have rather seen a more sensitive NCV setting and less sensitive Live Wire mode.
Non Contact Voltage Detection Method
NCV requires having the blade very close to the wire, best when to the side of it. Just having it in front of the conductor was not sufficient to elicit a response. It does rather well at differentiating the side of the wire bundle where the live wire is, just not in front of the socket. Most bars are shown and the display stays green with NCV. Voltage reading is always 0 in NCV duty.
Ergonomics
Most receptacles here in the USA are mounted vertically. Unfortunately, inserting the tip into the socket for metal connection requires turning the device on it's side, such that the display is not easy to read. I think the bit should be installed with 90 degree rotation, or the ability to change the orientation at will.
The display readability is OK. At certain angles some of the display goes out of contrast, and the thin letter "V" is hidden behind the label.
Here is a straight-on view. "AC~" and "LOW" are always in the display. The "LOW" shows even when the bar graph is at it's highest. There is a separate "battery low" icon when the battery voltage is <2.50V*, so there doesn't seem to be a purpose to the "LOW" text except showing where that end of the bar graph is. A bit confusing.
*If you decide to use 1.2V NiMH cells, you may experience lower contrast, lower backlight brightness, and continual low battery warnings. These images use 1.5V cells.
Live wire / Fire Wire detection method
Insert the slotted tip until the blade touches the metal conductor. For me, this required leaning the unit back and forth to find the metal, because my receptacles have narrow slots. Expect to see more of this lack of lead-in on newer socket holes for safety reasons. As long as your thumb is on the metal side tab, you will get some sort of voltage reading during direct contact to live wire. I found it was sometimes 20% lower than actual. When a live wire is found, the bar graph is pegged, the text "HiS" appears in the display, and the beeping is rapid and moderately loud (61 dB-A). The beep is an audible blend of mostly 2.6 kHz with lower amplitude harmonics of 5.3 and 7.9 kHz.
Inserting the unit into the neutral wire also elicits the same audible response and "pegged" bar graph. However, no voltage reading and green display instead of red.
The same thing happened when connected to the ground wire. Seems like a false positive to me. Also note how the screwdriver tip goes further into the larger ground hole.
From a safety point of view, I'm concerned about the metal touch tab on the side of the device. How do we know it's safe to touch metal while inserting the blade? Also, there isn't a clear differentiation between a live fire wire and the neutral zero line(s). The unit must be picking up a "ghost voltage" response because there is too much sensitivity. One range for both NCV and Live Wire through the same detection blade is showing up to be a poor compromise. The user does not have confidence in the unit’s differentiation between terminals.
The body shape mildly discourages your hand from touching the tip. Other units tend to have a wider, more sculpted plastic head in front of the hand grip. There is a plastic "cap" (I call it a collar) which adds additional distance to the conductor. I think the reason the collar can be removed is so the screwdriver accesses case slots where the head of the screw is deeper in a hole. This collar is very difficult to remove, but easier to replace. Don't lose it!
The battery access is easy and roomy for the AAA cells. Even the longest NiMH and Lithium primaries fit just fine. Well done
The flashlight feature, activated with a long-press of the power button, is helpful when using the tool in a dark room. It would be better if there were two LED's on alternate sides of the blade for less of a shadow.
Did I forget to remove the protective film? I guess I should stop giving Darren a hard time about that!
As a screwdriver, I would recommend keeping it to light duty. The case seems to have low torsional rigidity. Try twisting it moderately in your hands, and you can feel the case bend and the case halves shift. Also, I would not recommend using it for prying. I didn't try prying, but after tear-down I see there isn't much length of the tip anchored in the device and it goes directly into a PCB.
The pin appears to be overmolded in the bottom shell half. The front wall of the device (left wall in this picture) would be the weak link in a prying scenario.
As you can see, the soldering quality is above average. However, the side touch terminal appears to be soldered a little out of position with just one joint which melted the side of the case. It is not soldered either end of the strip... not sure if that is required. As a result, the exposed portion of metal outside the case is not sitting flat the way it does in product images. In the left I see a display driver, at the center the CPU COB, and on the right the low profile beeper. The + terminal of the beeper is marked, and there is an opening on the side of the beeper with an arrow where sound comes out. The current to the beeper is limited by a 100 ohm resistor, same for the flashlight LED.
Mechanically, I'm not seeing any special effort to make the case stronger against the stresses of using the device as a screwdriver. Only two small screws hold the case together without the aid of threaded inserts. Perhaps the lip around the perimeter of the case is helpful for some rigidity.
For safety, looking inside didn't decrease my concerns about safety touching the side blade. Not really seeing any interruptions (cuts) in the board or any optoelectronics isolating mains from the readout circuitry. Seeing that the metal can be soldered out of position and pass through the quality inspection adds concern.
Summary
Pros:
Versatile unit
Easy to use
Standard batteries, easy to access.
Compact and looks nice
Extremely low price
Cons:
One-range compromises.
Blade not narrow enough for newer US sockets, and turned the wrong angle for viewing the display.
Safety: while claimed rating is good, I feel it is questionable when looking at the construction.
Body strength likely insufficient for significant torque or prying.
Flashlight partially blocked by tip and collar.
Display is not always readable, and contains conflicting text information.
Neutral & ground wires detected similar to live wires while testing the provided unit.
Scanned User Manual:
Comments