Greenlee DM-820 DMM (rebranded Brymen) teardown - Page 1
Forum section: electronics / testgear

author: Mephitus
author_rank: Regular Contributor
timestamp: July 17, 2015, 06:53:15 pm
content: I recently made an eBay score of this Greenlee DM-820 for $31USD. Which from my research is just a rebranded Brymen BM859 [Thanks nanofrog]. Now, this is my first multimeter (which feels kinda silly since im 31 and all...) so keep that in mind for this review. I also do not have any testing standards to use yet, so performance testing/review will have to wait. It did come with some CAT IV test leads that are silicone coated with reasonably sharp tips.The first thing you notice about it in hand, is that it has a healthy heft to it and that the rubber case is firm with an extremely snug fitting to the meter itself. The selector switch feels very solid with no wiggle/play and a satisfying *click* with each change. As per the similar Brymen 800 series DMM that Dave reviewed, the backlight is completely laughable. Even in pitch black you can barely see it. As you can see in the pic below, its just 4 SMD LED's. This will need to be modded later. The LCD panel itself is large and very easy to read with a very respectable viewing angle. While I did buy this used, and as such it might be missing something, but when I popped the case there was one design flaw that stood out to me in that the battery compartment was NOT sealed with rubber like everything else. The screws are all captive with machine thread into metal inserts and a rubber o-ring.There seem to be a few changes from the similar model that Dave reviewed. For instance, this unit has RS232 connectivity with a send and receive capability. The shielding around the HRC fuses is removable to allow easier access for replacement. All of the lead jacks are solid metal with more o-ring seals. Oddly enough they decided to make the buttons onto a seperate board with board to board connectors.Overall, it feels very well built and designed (except where noted). I think I should get many years of good use out of this thing!Edit to add specs:Display: 3-5/6-digit, 5000-countVoltage Measurement 50.00, 500.0mV; 5.000, 50.00, 500.0, 1000VAmperage Measurement 500.0, 5000?A; 50.00, 500.0mA; 5.000, 10.00AResistance 50.00, 500.0?; 5.000, 50.00, 500.0k?; 5.000, 50.00M?Capacitance 50.00, 500.0nF; 5.000, 50.00, 500.0, 9999?FFrequency 10Hz-125kHzTemperature K type, -58 to 1832 Degrees F (-50 to 1000 Degrees C)Measurement Category CAT IV, 600V; CAT III 1000V

author: Mephitus
author_rank: Regular Contributor
timestamp: July 17, 2015, 06:55:13 pm
content: Some more pics that didnt fit in the first post limits.

author: Lightages
author_rank: Unknown
timestamp: July 17, 2015, 07:13:33 pm
content: That looks like a pretty fair assessment of the construction. Yes, it is surprising that the battery door is not sealed. The newer models are sealed so they have corrected this shortcoming. For the price you paid, you got a steal.

author: nanofrog
author_rank: Super Contributor
timestamp: July 17, 2015, 10:16:56 pm
content: Quote from: Mephitus on July 17, 2015, 06:53:15 pmIt's a BM859, so you did even better than you thought (temperature is the giveaway).

author: bitseeker
author_rank: Super Contributor
timestamp: September 22, 2015, 03:12:45 am
content: Quote from: Mephitus on July 17, 2015, 06:53:15 pmI recently scored similarly, Mephitus. Yours looks a lot better, though, than the photos of the one that's on its way to me. It'll be interesting to see how it ends up after a good cleaning.Regarding the temperature function, does anyone have recommendations for temp probes? Something that's comparable to the capabilities of this meter.

author: nanofrog
author_rank: Super Contributor
timestamp: September 22, 2015, 03:48:34 am
content: Quote from: bitseeker on September 22, 2015, 03:12:45 amIt just uses a standard K-type thermocouple.Most use the mini connectors, so you'd be best to get a banana adapter (cheaper).

author: bitseeker
author_rank: Super Contributor
timestamp: September 22, 2015, 04:31:43 pm
content: Thanks, nanofrog. Using the adapter would also make for a more flexible solution.

author: Robomeds
author_rank: Frequent Contributor
timestamp: September 22, 2015, 04:55:58 pm
content: That's a great deal! I picked up an Amprobe AM270 for about the same price a while back. The Amprobe is, to the best of my knowledge, the same guts but I prefer the Greenlee's housing and boot vs the Amprobe's just OK over molded housing. Take a look at the similarities herehttps://www.eevblog.com/forum/testgear/teardown-amprobe-am-270-digital-multimeter/msg70056/#msg70056

author: bitseeker
author_rank: Super Contributor
timestamp: September 23, 2015, 12:35:49 am
content: Yeah, I was pleasantly surprised to see that many of the specs of the older 820 were comparable to the 820A. Definitely good bang for the buck.

author: Trader
author_rank: Frequent Contributor
timestamp: February 05, 2023, 05:33:12 am
content: Quote from: Mephitus on July 17, 2015, 06:53:15 pmI know this is an old thread but seems the Greenlee DM-820 is like the Brymen BM857, not BM859.Some differences:- the AC Bandwidth that's 20kHz on Greenlee DM-820 and Brymen BM857, but 100kHz on Greenlee DM-860 / Brymen BM859 / Amprobe AM-160-A / Extech MM570A.- 1 temperature measure, not 2 temp measures like in the BM859- a little less accuracy in almost all scales- I'm not sure if has AC+DC measurements.https://www.welectron.com/mediafiles/datasheets/brymen/Brymen_BM850s_Datasheet.pdfAnother curiosity, Greenlee released a new model also called "DM-820", but it's a 10,000 counts meter.Greenlee DM-820 is still an excellent DMM ($31 is a giveaway), I'm just clarifying the comparison.And just to add another comparison, seems the BM859 is a little more precise them the BM869 in DC voltages:- between 5V and 50V (0.02%+2d vs 0.03% + 2d)- above 500V (0.05%+2d vs 0.15% + 2d)* Input Impedance: 10M, 30pF nominal (80pF nominal for 500mV range) vs 60pF.

author: Trader
author_rank: Frequent Contributor
timestamp: February 05, 2023, 05:51:03 am
content: WOW, another fix (I won't modify first post).After reading:https://www.eevblog.com/forum/beginners/looking-for-help-selecting-a-budget-multi-meter-im-quite-overwhelmed/msg2411139/#msg2411139Seems that THIS "Greenlee DM-820" is the BM815s, not the BM857s.http://www.brymen.com/PD02BM810s_815s.htmlIt's crazy, but seems that Greenlee released some DMMs with the same model name "DM-820".Quote from: Trader on February 05, 2023, 05:33:12 am

author: J-R
author_rank: Super Contributor
timestamp: February 05, 2023, 11:58:04 am
content: DM-820 vs DM-820A...From what I'm seeing:Greenlee DM-820 is the original Brymen BM815, without the "s", so no BeepJack feature.Greenlee DM-820A is the BM827s but adds a backlight. I don't see a Brymen that matches this exactly, maybe a custom tweak per Greenlee's request?

author: Neutrion
author_rank: Frequent Contributor
timestamp: February 06, 2023, 04:17:41 pm
content: Is that a Hycon IC made in Japan? Or they used something different?