advice needed 34401A or siglent SDM3045x? - Page 1
Forum section: electronics / testgear

author: marmelade
author_rank: Contributor
timestamp: September 09, 2018, 09:03:41 pm
content: Dear Forum,I am currently looking for a Bench-DMM, that fits my needs. One of the main applications, apart from general bench use, will be testing DCDC and ACDC converters. Accuracy-wise 4.5 digits will be more than sufficient. Simultaneous display of DC-Current and DC-Voltage (often called dual-display) for eff. estimation would be a HUGE bonus. Since I am also aiming at automation, GPIB and/or LXI are welcome, a serial interface would be mandatory.Now setting the budget to around 400 euros, I am facing the following options:* A used 34401A, qood quality meter, no dual display, only 3A Current range, GPIB-interface* A used FLUKE 45, 10A current range, GPIB per option available, very old* A new Siglent 3045X, dual display and current range up to 10A and LXI-interface* A new GW-Instek GDM-8341 4.5 digit meter with dual-display and usb-serial-interfaceDismissing the FLUKE (400 is imo very expensive for the age of the instrument) and the GW-Instek (I'd prefer a proper GPIB or LXI Interface over the usb-serial stuff). I am torn between the 34401A and the Siglent. Normally I'd rather aim for high quality, but used, than for cheap new equipment but the dual-display option and the high current range seem very appealing to me for general bench use (without automation involved).What would you do? Any siglent users? Thank you very much for your input!

author: tautech
author_rank: Super Contributor
timestamp: September 09, 2018, 09:11:55 pm
content: The Siglents while able to do dual measurements can't do simultaneous V and A. Instead they cycle between measurement types.Even the 16ch logging card/module for their 3055 and 3065X operates in this way.Check the specs carefully between 3045 and 3055 as IIRC there are differences that make a 3055 the better choice.

author: nctnico
author_rank: Super Contributor
timestamp: September 09, 2018, 09:16:17 pm
content: For your budget you can buy 2 Vici 8145 bench DMMs. These have a serial interface (the protocol is somewhere on the forum) and with two meters you can measure voltage and current simultaneously.

author: marmelade
author_rank: Contributor
timestamp: September 11, 2018, 09:18:26 pm
content: Sorry for the late reply, life kept me buisy over the past 2 days. Thank you very much for the suggestions. I also had a second look at the dual-display capabilities of the Siglent devices. Not the same, but similar.Giving the whole matter a second thought, I am currently leaning towards buying the 34401A. Current ranges can be extended by external 10m or 1m shunt resistors. Also the dual display-switching via relays is probably not the most relaxing working environment.

author: tautech
author_rank: Super Contributor
timestamp: September 11, 2018, 11:07:31 pm
content: Quote from: marmelade on September 11, 2018, 09:18:26 pmI don't know which bench DMM's don't operate in this way for V & A dual measurements. Best you research this well or use 2 meters.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 12, 2018, 02:15:44 am
content: If you want an true dual isolated channel bench meter there is one $$$ : ADCMT DMM 7352A (A channel : 10pA to 2A and B channel: 100μA to 10A) not for America and AsiaCant recall the other brand i saw ...

author: bitseeker
author_rank: Super Contributor
timestamp: September 12, 2018, 02:20:24 am
content: DMMs that measure V and A simultaneously are pretty rare, which usually means they'll be expensive. Just use two meters. It's good to have a backup DMM anyway.On the 34401A, make sure that there are no dots lighting up that shouldn't be illuminated. That's a sign of display problems.

author: marmelade
author_rank: Contributor
timestamp: September 12, 2018, 07:13:47 pm
content: Yeah, the more I am thinking about it, the more am leaning to having two seperate meters. It just makes more sense.

author: marmelade
author_rank: Contributor
timestamp: September 18, 2018, 05:28:34 pm
content: Just to finish this... found a used FLUKE 45 for an acceptable price. I*ll add a second meter soon, but I am not decided on the model yet. In the meanwhile I can rely on the dual-display feature of the old FLUKE.Thanks a lot for all your input!

author: bitseeker
author_rank: Super Contributor
timestamp: September 18, 2018, 05:36:52 pm
content: Very nice. Thanks for the update. Happy measuring!

author: Electro Fan
author_rank: Super Contributor
timestamp: June 03, 2019, 03:49:37 am
content: Quote from: tautech on September 09, 2018, 09:11:55 pmOld thread I realize but I'm betting tautech finds thisThe attachment below from the Siglent manual indicates it does a dual display of V and A. Just checking to see what this means given your previous post above....Alternately means that the DMM measure A then V then A, etc and displays the results, so they are not realtime simultaneous, but interleaved over some (TBD) duration?Thx

author: tautech
author_rank: Super Contributor
timestamp: June 03, 2019, 05:23:03 am
content: Quote from: Electro Fan on June 03, 2019, 03:49:37 amCorrect, ~1 reading/s alternating between the dual measurements selected.I don't see a spec in the datasheet for the frequency of each reading while in Dual mode however it's ~1s, so each measurement type is taken every ~2s.P53/109 lists a table of the dual measurements that can be selected.http://www.siglentamerica.com/wp-content/uploads/dlm_uploads/2017/10/SDM3045x_UserManual_UM06034-E01A.pdf

author: maginnovision
author_rank: Super Contributor
timestamp: June 03, 2019, 06:19:57 am
content: Also R&S have the HMC8012 that does V/A without clicky relays. Not exactly pertinent information now but thought I'd add it here since it was part of the discussion and the thread came up.