TEK DMM 4020 - Page 1
Forum section: electronics / testgear

author: GigaJoe
author_rank: Frequent Contributor
timestamp: March 27, 2023, 08:40:06 pm
content: for US230are good deal ? local offerscreen seems ok ; no troubles looks like at first look should i rush in ?

author: bdunham7
author_rank: Super Contributor
timestamp: March 27, 2023, 09:17:36 pm
content: If you need or want a good but less-precise bench meter, that seems pretty good. The Fluke equivalent 8808A is over $1K and is a current model.

author: Miti
author_rank: Super Contributor
timestamp: March 28, 2023, 03:21:07 pm
content: It is 5.5 digit meter. You could get a better deal for a 6.5 digit HP 34401.Just saying.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: March 29, 2023, 02:46:40 am
content: less then us300 for HP - unrealistically luckyi saw milometer 80-x circa fly away for over US1100seems of new era skyrocketing everything but wages

author: shakalnokturn
author_rank: Super Contributor
timestamp: March 29, 2023, 05:37:58 pm
content: Even here in France where T.E. seems to sell for more than in U.S. or Canada, I'll usually stay below 100€ for a 5.5 digit meter.If there's nothing better / cheaper going and you really need it why not, check the calibration as well as you can before buying, the price would be steep for a meter that isn't working as intended or needs readjusting.The average price over here for a used HP 34401 would be around 500€ occasionally they go for half of that.I bought my Keithley 2100 which is a 6.5 digit meter for 220€.

author: bdunham7
author_rank: Super Contributor
timestamp: April 12, 2023, 08:59:26 pm
content: I just happened to acquire one of these and thought I'd revisit the topic now that I've got my hands on one. I'd say again that for $230 if you want a decent bench service meter you should grab it.It is an updated replacement for the Fluke 45--which can go for nearly $200 on eBay--except that it is much, much better than a Fluke 45.Important features include:* Hi-Z input for 0.2 and 2VDC ranges.* The "I-Lkg" function which is a transimpedance input for the two lowest current ranges--0.2 and 2mA--that gives them a very low burden voltage.* Versatile dual-display that can read current and voltage using 3 leads, AC and DC (but not AC + DC), AC and Hz and more. The meter can independently autorange both readings. One shortcoming is that it really doesn't doPSU ripple very well in this configuration because the switching results in a 'floor' on the AC readings that is higher than it is with a single reading.* 4W ohms with the Fluke-exclusive 2x4W system that allows you to get very accurate low resistance readings with normal-looking probes and no Kelvin clips or 4-wire connections.* 200,000 count operation in native mode, 100,000 count in the selectable Fluke 45 emulation mode. It really is a Fluke 45 replacement and effectively becomes one with two button presses for F45 mode.It doesn't have temperature, capacitance or USB. It has an RS232 interface (no GPIB) and is relatively simple to use. Like the Fluke 45, the specs are a bit more relaxed (150ppm basic DC accuracy) and it is only marginally more accurate than a very high end handheld. It presumably has a bandgap reference and in my initial testing it does have some tempco, so not in the same league as an 8842A, but almost as good as an 8840A or HP 3478A and way better than a GW 8251A. So far it more than meets its specs.HTH.

author: Nikola Tesla Junior IV
author_rank: Contributor
timestamp: April 12, 2023, 09:16:07 pm
content: A bit late - Everything else aside, $230 for a DMM4020 is a great deal, period.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: April 13, 2023, 03:43:19 am
content: hello grandpa

author: GigaJoe
author_rank: Frequent Contributor
timestamp: April 13, 2023, 04:43:41 am
content: yeah bought broken fluke 45 , then repair it , it 1.00000 in slow, and 3.0000 in medium fast. medium with wide range very handyspeaking of tek\flukefront power button don't off the unit ; transformer still on ; and large switch on back.range jumping from high to low ; usually otherwise. jumping not as fast as i wish.in slow - it slow ... 2.5 count , so so .. in med 20 \ sec - very nice2x4Wire - perfectly adding probe resistance , ( should i have Fluke certified probe for the same price ? ) so marketingAC excellence up to 900K , and sharp cut at 1Mhz - great surprisebeeper oktoo sad no caps measuresettings rudimental, min\max offset ...Contruction \ case . i seen better design .why no 20.0000 mV range like 8042 ?20.000 microAmps seems have 2 ohm resistance ... that something ...and dial display, hmmm , it slow, measure one then switch on another slow measure again - even med mode didn't help, comparing to fluke45display itself - large easy readable.so for used one i would say optimal around 230-250 320 if you reealy wish it ( as it an overpriced fluke ), and 350 are region of 34401and for 320 i rather hunt for 2 x 8040A - would be same dual display

author: bdunham7
author_rank: Super Contributor
timestamp: April 13, 2023, 01:56:09 pm
content: 2X4 resistance requires specific 2X4W probes with split plugs and coax cables.https://www.tequipment.net/search/?F_Keyword=2x4w

author: GigaJoe
author_rank: Frequent Contributor
timestamp: April 13, 2023, 02:26:18 pm
content: ah .. it seems connector split in half

author: shakalnokturn
author_rank: Super Contributor
timestamp: April 13, 2023, 04:55:05 pm
content: That's only to detect insertion to that socket, for 4 wire measurements you need 4 banana plugs, 2 to high, 2 to low.Edit: Well correct me if I'm wrong... That's at least what I'd expect from a DMM with High and Low sockets.

author: bdunham7
author_rank: Super Contributor
timestamp: April 13, 2023, 05:02:14 pm
content: Quote from: shakalnokturn on April 13, 2023, 04:55:05 pmNo, the Fluke 2X4W system has the source and sense connections on the same jack. So if you look at it, the left half of the jack is the source connection and the right half is connected to the sense. With normal test leads the single banana would short the two together, so you'd just have normal 2W ohms and any other function. In 4W mode, the right half would be disconnected and the sense circuit would be connected to the jacks to the right. The 2X4W test leads use a matching split banana jack that connects to the two halves independently and then keeps the two circuits isolated via a coax cable all the way to the probe tips. The result is 'almost 4W' operation because you still have the probe tip and tip contact resistance in common. In practice it works pretty well down to the single-digit milliohm level. You could construct a true 4W system using this setup by replacing the probe ends with Kelvin clips, but Fluke doesn't sell them this way.

author: bdunham7
author_rank: Super Contributor
timestamp: April 13, 2023, 06:19:37 pm
content: Quote from: shakalnokturn on April 13, 2023, 04:55:05 pmYour expectations actually aren't unreasonable, this case is just a fluke.You might expect that for a single-probe near-4W result you could just use something like this (and you can).https://us.rs-online.com/product/pomona-electronics/6303/70198464/?gclid=CjwKCAjw0N6hBhAUEiwAXab-TZvrW4SWl5qIght7jQBfHM05xa5YTs7FUF1dW_XrpbJB4ShA9GOlyRoCqEUQAvD_BwE&gclsrc=aw.dsAs far as I can tell the only significant advantage of the Fluke 2X4W system is that you can use the same set of probes for 2X4W resistance and all of the other voltage functions, whereas you might not want to measure 1000VAC with the 4W probes still connected, at least on some meters.