Hi, I opened my Testboy TB-3000 multimeter. It's about 70,-€ in Germany.
Have some impressions.
It might just be the angles, but...these look awfully close to each other on the input protection. I think a spark might be able to jump that distance.
And the soldering...
Looks like someone cleaned their soldering iron at the current shunt...
That's called "calibration".
Looks like the resistance was a little bit high so they added some extra solder to fix it.
TÜV Süd/GS approved
The design looks OK but I bet the meter they submitted for approval wasn't soldered/assembled by the same person that soldered/assembled yours.
That's called "calibration".
To quote Dave, it is done by nude virgins or old gray beards with their tongue the correct angle. But, I think you are correct, in this case old Bathild looked at the meter in a test rig and cleaned the tip of her soldering iron on the shunt.
That's called "calibration".
To quote Dave, it is done by nude virgins or old gray beards with their tongue the correct angle. But, I think you are correct, in this case old Bathild looked at the meter in a test rig and cleaned the tip of her soldering iron on the shunt.
No, it's true!
Normally they're manufactured a bit low and they put a few "nips" in them with a pair of side cutters until it reaches a known value, like this:
(sort of like laser trimming but without the lasers)
If it's a bit too high? Add a blob of solder!
Or... they might just have been cleaning their soldering iron.
Horrible build quality
. I am in doubt that the TÜV / CE certification is real . Scammer
Is this a rebranded Mastech or something??
Horrible build quality . I am in doubt that the TÜV / CE certification is real . Scammer
the certification is only done on a submitted device - the one they built carefully and de-fluxed first!!
Yeah, before I put it back together, I bent them apart and put some hotglue (forgive me) between the leads.
Careful with that. When you put glue on it, I think you have to worry about creepage distance, which is greater than the clearance requirement for a given voltage. With hot glue, though, you probably couldn't easily put on a blob that's too small.