EEVblog Electronics Community Forum
Products => Other Equipment & Products => Topic started by: Zensei on October 01, 2011, 03:39:23 pm
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Hello people :)
I want to start out by saying that I'm not an electronics expert (YET ;) ). So take this review for what it is.
I am, however, a student of Marine Engineering at the Copenhagen Marine Enginneering Academy in Denmark. So I am learning.
As we properbly all know, life as a student is not always blessed with a big bankaccount...
But, as my interest in electronics grows, I'm building a decent electronics lab with the means available to me. I was in the market for a benchmultimeter for my workshop, so I started searching the various brands. My budget was around 600$, so I started researching. I found this Tonghui TH1942 for around 300 euro. But I couldn't find ANY reviews or even pictures of the inside. So I thought I would be the first. I took the chance :) Hopefully it will benefit others in the same situation. I also tried out the Uni-T 804, if you're interested, my experience with that can be read here: https://www.eevblog.com/forum/index.php?topic=4672.0 (https://www.eevblog.com/forum/index.php?topic=4672.0)
At present, I have the following equipment:
1 x Trio 15 Mhz analog oscilloscope, 2 channel
1 x Advance instruments analog power supply 0-50 V DC
1 x Tekway DST1102B Oscilloscope (Not hacked, yet)
1 x Uni-T UT81B Handheld Oscilloscope and multimeter
1 x Elit 60E2 (Uni-T UT60E rebranded) it is starting to act up, so it will properbly be scrapped soon.
1 x Uni-T UT204 Clampmeter
1 x Uni-T UT603 LCR meter
1 x Tachometer (cheap ebay one)
1 x Infrared thermometer (cheap ebay one)
1 x Aoyue 936 Soldering station
And now for my latest 2 meters, one of which I will review today:
1 x Uni-T UT71E Handheld Wattmeter/multimeter
1 x Tonghui TH1942 Benchmultimeter.
I will be reviewing the Tonghui in this thread, as promised..
Tonghui TH1942:
The unit feels decent for the price. It is definitely a better built meter than the UT804. Well worth the extra price, if you can do without the extra features that the Uni-T has. It has a metal casing with rubber corners for firm surface grip.
It is quite fast at autoranging, compared to Uni-T meters. Since I don't have a suitable powersupply, I can only measure DC 0-50 V and compare it to my Uni-T meters. But I don't see the point really, given the small range I have available.
The meter measures AC/DC/freq/Diode/Ohm/Amps.
I do miss a capacitance measurement feature. But ya can't have it all :)
The Uni-T UT71E is a handheld multuimeter with a power measurement feature.
It cost me 159 euro from www.pinsonne-elektronik.de (http://www.pinsonne-elektronik.de) same place I bought the Tonghui.
It comes with a cord for measuring power consumption of household appliances.
It has the typical build quality of other Uni-T meters. It is very accurate, although a bit slow at autoranging and so forth. The continuity test is a bit slow, compared to more expensive meters.
I will do more in-depth review of the features of both meters in a video when I have more time.
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More pics
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and more
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And the last ones :)
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Just the view of the new high quality electrolytic capacitors in the UT71E.
Brings tears of joy in my eyes.. ;)
Even the 9V battery has the UNI-T logo.
The mains voltage specialized probe, makes the mains volts measurement an fool proof task.
More tears of joy in my eyes.. ;)
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The mains voltage specialized probe, makes the mains volts measurement an "fool" proof task.
nothing is "fool" proof, even Gossen when operated by a kid.
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Well this adapter? probe ? I do not know how to name it.
Has an fixed banana adapter, that plugs directly on the DMM at the right points. ( Voltage bananas)
And this eliminates the chance to plug your leads on the current sockets.
This is why I had baptized it as fool proof.
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Is there anything inside the TH1942 small metal case on the PCB?
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My guess is that the voltage reference and related circuitry. I've seen this also in other bench meters. Construction of the TH1942 looks decent, although some of the through-hole components are not installed flush to the PCB, like some resistors near the resistor array.
It's not clear to me where the isolation boundary between the floating and grounded part of the circuit is, I would expect an area with several millimeters of clearance. Is the 'main' MCU also part of the floating circuit? That would be unusual.
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My guess is that the voltage reference and related circuitry. I've seen this also in other bench meters. Construction of the TH1942 looks decent, although some of the through-hole components are not installed flush to the PCB, like some resistors near the resistor array.
The thing I would immediately fix is the current shunt touching the input wires.
(https://www.eevblog.com/forum/index.php?action=dlattach;topic=5012.0;attach=15499;image)
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The current shunt does not touching anything.
Its just an false impression, due the angle that the picture was taken.
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Is it just me or did they really leave out most of the input protection circuitry?
Also what's with the glass fuses? Even the UT61D had HBC ones. Weird.
Florian