EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: retiredcaps on February 16, 2015, 07:20:50 am
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BigClive, a member here, made an video on the Amecal ST-9927T and I thought I would make some comments here.
Test and look inside Amecal ST-9927T multimeter. (https://www.youtube.com/watch?v=QOvmVK1G_3c#ws)
1) CEM is the ODM for this meter. They make multimeters for Extech, Craftsman, Southwire, Reed, MTP, Major Tech and others.
http://www.cem-instruments.com/en/pro/pro-244.html (http://www.cem-instruments.com/en/pro/pro-244.html)
2) The IC is a FS9922. Datasheet is at
http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-12_EN.pdf (http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-12_EN.pdf)
The FS9922 is used in some Uni-T and Vichy multimeters among others.
3) The picture on Amecal's website (attached) for the FS-9927T is totally different from the one in your video.
4) The Fluke 18B+ is Made in China. The Fluke 18B+ might come in an International version at a later date. Currently, there are no known Fluke multimeter counterfeits.
5) Since the 9927T has the off position in the middle, be careful not to over rotate it going to temperature. Martin shows what can happen in this short 2 minute video.
https://www.youtube.com/watch?v=zf9BYiYzGIo (https://www.youtube.com/watch?v=zf9BYiYzGIo)
6) The Fluke 23 is a nice meter, but its bigger brothers like the Fluke 80 series are faster in terms of displaying a reading and beep/continuity. On the other hand, the Fluke 23 has an astounding 2000 (two thousand) hour battery life using a standard 9V alkaline.
7) It was difficult to see in your video, but can you provide some close up photos of the pcb so we can see the soldering quality?
In the past CEM has manufactured some very poor quality soldering and I'm curious to see if they have improved in this area with a meter made in 2015. For examples, see
http://mrmodemhead.com/blog/gallery/craftsman-82003/ (http://mrmodemhead.com/blog/gallery/craftsman-82003/)
https://www.eevblog.com/forum/testgear/teardown-extech-ex570-my-first-but-also-last-extech/ (https://www.eevblog.com/forum/testgear/teardown-extech-ex570-my-first-but-also-last-extech/)
https://www.eevblog.com/forum/testgear/extech-ex330-quality-issue/ (https://www.eevblog.com/forum/testgear/extech-ex330-quality-issue/)
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I've had a good look inside this unit and it all looks quite acceptable. The only two dodgy-looking solder joints are the two for the LCD's backlight that have had a little too much solder applied. Other than that the only obvious slight assembly quirk was the crystal case being slightly off level. Not really a show-stopper though.
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Thanks for the pictures BigClive.
BTW, the pcb board on yours says EX520 which is for the Extech 520.
http://www.extech.com/instruments/product.asp?catid=48&prodid=267 (http://www.extech.com/instruments/product.asp?catid=48&prodid=267)
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I didn't spot that. That particular Extech version being on ebay for between twice and three times the price!
I wonder if it's built to ExTech's specification and then rebadged for other sellers, or if ExTech are just their biggest customer in that area.
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Well it looks quite sililar to the Extech multimeter Dave tested at the shootout long time ago . Here in Europe you also can buy it at ebay under the PAN brand
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Well it looks quite sililar to the Extech multimeter Dave tested at the shootout long time ago .
Yep, looks very similar.
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Well it looks quite sililar to the Extech multimeter Dave tested at the shootout long time ago .
Yep, looks very similar.
Yes if I remember me correctly the Extech was the multimeter where they bodged a piece of wire in it because the board was broken off on the left downside ;D
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I know everyone does the "will it light a <insert colour> LED" test for the diode check but it makes more sense to put a 10K potentiometer inline with another meter on DC mA. Then by adjusting the pot you will be able to observe both the voltage at which the meter displays OL instead of the voltage drop, and the point where the current starts to fall from the nominal 1-2mA. Measuring the open circuit voltage is pointless because (for e.g.) a Fluke 87 provides over 7V OC but the display goes OL at around 3V iirc and the current is already dropping off by 2V.
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Check this out, this looks like a 40,000 count/0.06% version of the same meter:
(http://files.elv.de/bilder/artikel/Produkte/8/870/87076/Internet//gross/87076_w01_multimeter.jpg)
http://www.elv.de/digital-multimeter-dm9199-ip67.html (http://www.elv.de/digital-multimeter-dm9199-ip67.html)
Edit: cheaper here: http://www.shop.display3000.com/messgeraete/true-rms-multimeter_-ip67_-beleuchtet-2.html (http://www.shop.display3000.com/messgeraete/true-rms-multimeter_-ip67_-beleuchtet-2.html)
It looks very similar to the Extech EX530 and has similar specs, but the dial is different:
(http://sigma.octopart.com/17578840/image/Extech-Instruments-EX530.jpg)
Here's a review (German):
http://h-reg.blogspot.de/2013/03/review-elv-dm9199.html (http://h-reg.blogspot.de/2013/03/review-elv-dm9199.html)
Construction looks very similar to the 9927T with big fuses. According to the reviewer, he doesn't like the slow update rate and the slow beeper.
Here is a version with a 2,000 point data logger:
http://www.elv.de/digital-multimeter-dm9299-ip67.html (http://www.elv.de/digital-multimeter-dm9299-ip67.html)
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I know. This is an old thread.
But i just want to say that here in Norway we can get this multimeter from a store called "Biltema" for 749NOK. Or 87$. I think this multimeter is the same?
Just zoom in on the picture.
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Here is som better photos:
(https://i.ibb.co/N1wm4M7/1.jpg) (https://ibb.co/WDSPTLs)
(https://i.ibb.co/8DJfhft/2.jpg) (https://ibb.co/tMSvdvF)
(https://i.ibb.co/wCWsVX0/3.jpg) (https://ibb.co/k081jfH)
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I do not have a lot of electronic experience, but i have not had any problemes with that multimeter. I works perfectly. The continuity tester is pretty responsive to. Regards to other videoes i have seen on Youtube it is almost the same as the Fluke regards to that.