What are your experiences with the GW Instek GDM-8245? - Page 1
Forum section: electronics / testgear

author: FriendlyWire
author_rank: Newbie
timestamp: July 07, 2019, 04:56:46 am
content: I mainly work on small microcontroller projects as a hobby, and recently I decided to get a bench multimeter because my handheld one is always in the way on my small workbench. I found a used GDM-8245 [https://www.gwinstek.com/en-GB/products/detail/GDM-8245] for $CA 150, which I think was a good deal. It hasn't arrived yet, and I have a 30-day return period, so no worries.What are your experiences with this meter?CeeersJens

author: GerryR
author_rank: Frequent Contributor
timestamp: July 07, 2019, 11:28:06 am
content: Just looking at the specs, I would consider two things, first the AC TRMS is limited to 50 KHz and frequency measurements are limited to 200 KHz. If your expected testing is within those limits, then fine. (Many meters have AC TRMS good to 100 KHz ,and as you go up in price, to 300 KHz and frequency to over 1 MHz.) In general it seems to have a lot of functionality. GWInstek has been around for awhile and makes some descent equipment. JMO.

author: coromonadalix
author_rank: Super Contributor
timestamp: July 07, 2019, 11:55:32 am
content: At 150$ Cad seems a good offer, as GerryR said, if the specs are fine with you, for a first bench dmm thats okDont think i has schematics available, and the calibration price if ever needed should not be high.Would be nice for eevbloggers, if you could pop off the case and take / show us the inside and some ic's markings thks

author: FriendlyWire
author_rank: Newbie
timestamp: July 07, 2019, 11:51:15 pm
content: @GerryR: Thanks for drawing my attention to this. I think 50kHz is fine, I don't think I will be needing it that much. I hadn't really heard of GW Instek but apparently their marketing has only recently picked up...@coromonadalix: I couldn't find schematics anywhere, but since my unit is supposed to be working I won't be needing it right away. I hope I will have time to take some photos of the inside when it gets here. Should I start a new thread in that case or just post them here?

author: NoisyBoy
author_rank: Frequent Contributor
timestamp: July 08, 2019, 01:45:36 am
content: In most microprocessor projects, you are probably not spending a lot of time dealing with AC, and if you want to look inside the signal, you would want a scope with a logic analyzer anyway, so I would be perfectly happy with the spec.In buying second hand DMM, other than ensuring that everything works, is that it is within cal spec. Depending on the type of accuracy you need, you may want to either verify it against a known reference voltage, just so you can trust it. If accuracy is crucial, then a trip to the cal lab would be well worth the money to give you full confidence.I think of this as changing the fluid in a used car when you get it if the previous owner cannot show you the service record.

author: FriendlyWire
author_rank: Newbie
timestamp: July 08, 2019, 02:09:49 am
content: Good point! I might ask the electrical engineers at my university if I can sneak into their precious lab to check if my meter is still within spec or not.

author: targit
author_rank: Regular Contributor
timestamp: July 09, 2019, 04:30:19 am
content: I have this as my bench meter, basic and easy to use. Nice bright LED digits can be read from across the room if you are monitoring a project from coffee making department.

author: coromonadalix
author_rank: Super Contributor
timestamp: July 09, 2019, 07:48:08 am
content: When you'll get your unit, start a thread with a title like this : " GwInstek GDM-8245 teardown / photos ", remove the top case and take many photos in maybe 2 -3 consecutive threads ??I generally hate all the vfd's based meters ... i have a few 34401a, managed to get 2x vfd substitutes from Aliexpress at 30$ usd / ea who works wonder ... at keysight an front panel pcb with an genuine vfd is 200$ usd ... outch. The prices skyrocketed. BUT when Aliexpress put an low priced "chinesium clone" vfd for sale, strangely many thoses on Ebay dropped in pricesI love the leds display, less problems to see them and repair them if needed.A member here managed to convert 2x vfd display into leds display for a Datron 4000 calibrator, he did a very good / incredible job, since the vfd are unobtanium and where broken in the shipping."Old gear" like your meter get attention and the prices goes up, even old hp 3478a price(s) are higher nowAttachments:Restrictions: 25 per post, maximum total size 5000KB, maximum individual size 5000KB

author: FriendlyWire
author_rank: Newbie
timestamp: July 09, 2019, 02:33:10 pm
content: @targit: Thanks! I am glad I found someone who actually has it and likes it.@coromonadalix: Yes, I really wanted to get a bench multimeter with a decent readout, none of that LCD/VFD stuff. It is a device I will use a lot, and I don't want to get upset every time I look at it. The display is so important to me that I am even willing to sacrifice one or two digits of precision. Is that crazy? Thanks for your advice on the teardown thread, I will do my best!

author: NoisyBoy
author_rank: Frequent Contributor
timestamp: July 09, 2019, 04:02:34 pm
content: If you have access to an university EE lab, that would be a good place to verify the reading on your DMM. Unfortunately, the owner manual for the DMM does not specify what to check for, so you will have to just do spot check of various functions.LED lasts forever and they are big/easy to read. It is a good compromise amongst cost, features, and durability as a DMM display. The ones on your model looks excellent.

author: GerryR
author_rank: Frequent Contributor
timestamp: July 10, 2019, 12:04:36 am
content: Quote from: targit on July 09, 2019, 04:30:19 amThat's how you tell a real engineer; if one of their arms is not sticking out at right angles to their body, and their fingers are not curled from holding coffee cups, then their profession is suspect!

author: FriendlyWire
author_rank: Newbie
timestamp: July 10, 2019, 01:26:01 am
content: I'm a theoretical physicist but I am also quite fond of coffee. Does that count? ;-)

author: GerryR
author_rank: Frequent Contributor
timestamp: July 10, 2019, 11:10:13 am
content: Quote from: FriendlyWire on July 10, 2019, 01:26:01 amThat works if your arm is suck out and your fingers are curled!

author: Herbertl
author_rank: Contributor
timestamp: July 25, 2019, 05:15:03 pm
content: Looks great and price does as well.Would like to get me one.Anyone yet tested if it is within specs?

author: targit
author_rank: Regular Contributor
timestamp: July 26, 2019, 03:13:17 am
content: My only criticism is the slow(ish) continuity buzzer, but I generally use a portable Fluke 85 for that, while the bench meter is hooked up to monitor power supply or other "long term" measurements.

author: coromonadalix
author_rank: Super Contributor
timestamp: July 26, 2019, 06:58:38 am
content: Would love a teardown, photos of it guts and chip markings ...

author: FriendlyWire
author_rank: Newbie
timestamp: July 30, 2019, 12:50:55 am
content: The multimeter arrived! I have no idea how to open it, though. Need to find a spatula or something to pry the plastic open, but I don't want to break it. Any advice?@targit: oh yes, continuity is super sluggish unfortunately. The rest seems to be working fine (was a used unit).

author: coromonadalix
author_rank: Super Contributor
timestamp: July 30, 2019, 03:12:17 am
content: maybe it slide ??take some photos of the rear and bottom case, maybe you have removable rubber feets who hide screwsseen a picture, maybe you have te remove the top rear center screw and try to lift from the rear section while going/rotating forward ??, like an hinge ( sorry can't find the right english wording)

author: 001
author_rank: Super Contributor
timestamp: July 30, 2019, 02:48:37 pm
content: Honey, Instek is well knownindustrialgear in Asia. Not DIY crappy metersService manual and schematics are attachedI got it years ago and I hope its helps You now

author: FriendlyWire
author_rank: Newbie
timestamp: July 30, 2019, 11:42:29 pm
content: This is great, thanks so much for the manual! I guess that means I don't have to take it apart anymore!

author: Nx-1997
author_rank: Regular Contributor
timestamp: July 31, 2019, 02:07:43 am
content: Few years ago, you could pick up a GDM-8251A for around $150 CDN. Now that was a steal. I paid $200 CDN for one, including shipping & tax.

author: coromonadalix
author_rank: Super Contributor
timestamp: July 31, 2019, 02:54:56 am
content: yep when the people got "curious" loll the prices went up