WTB (EU): Used Keithley 2001 or 34470A - Page 1
Forum section: electronics / general

author: Echo88
author_rank: Frequent Contributor
timestamp: October 06, 2016, 07:37:20 pm
content: Im infected with the voltnuttery-virus and the only cure is to get a suitable Meter.So if you want to sell your used Keithley 2001 Meter or a 34470A for a reasonable price let me know. Preferably from Germany, but the whole EU is okay.

author: Berni
author_rank: Super Contributor
timestamp: October 06, 2016, 08:23:42 pm
content: I suggest getting the keithley if you are choosing between the two.I have a Agilent 34461A that i was not all that impressed with it. Thinking of selling it and buying another Keithley with it. But hey that's just my use case, the Keysight ones do have certain features that you don't get elsewhere easily.

author: eponte5
author_rank: Newbie
timestamp: October 07, 2016, 11:32:46 am
content: What kind of features does the Keithley have that you speak of?

author: Berni
author_rank: Super Contributor
timestamp: October 07, 2016, 12:27:22 pm
content: Quote from: eponte5 on October 07, 2016, 11:32:46 amIt boots in 3 seconds versus the 20 to 30 of the Keysight. You get faster display updating at high resolutions and it has some smaller ranges to let you measure tiny things. Keysight on the other hand has built in ethernet and USB, also has the ability to draw a graph with a push of a button and save it to a csv file. The LCD display versus the VFD display is kind of a personal opinion but i prefer VFD displays.On the other hand the Keithley 2001 is a old design (Lots of troughhole construction inside). We just got a new more modern Keithley 2100 at work and i quite like it. Still not quite as feature rich as what Keysight offers but still makes a great every day multimeter and it is reasonably priced (Its accuracy is not really volt nut material tho).Not saying the Keysight is a bad multimeter, i just personaly find the Keithley better suited for day to day use of poking around boards.

author: Andreas
author_rank: Super Contributor
timestamp: October 07, 2016, 06:41:10 pm
content: Sorry but the K2001, K2010 have no LTZ1000 but a LM399 as reference.The DMM7510 is based on LTFLU-1 referencewith best regardsAndreas

author: Echo88
author_rank: Frequent Contributor
timestamp: October 07, 2016, 09:27:07 pm
content: Of course a LTZ1000 based DMM would be nicer driftwise, but i simply dont want to spend 4k€ on a 3458A (not to mention if its needs calibration/repair, brings tears to my eyes just thinking about the price). So whats left are the next best DMMs around 1k€, which is in my price range. And i chose to buy the Keithley 2001 because its more common on the surplus-market than a 34470A or a DMM7510. Havent really checked the DMM7510, but a 34470A would a also suffice my needs.And if i think i need another Digit, i have the possibility to use a 3458A at work sometimes.

author: Dr. Frank
author_rank: Super Contributor
timestamp: October 08, 2016, 06:05:17 am
content: Quote from: Echo88 on October 07, 2016, 09:27:07 pmDon't be blinded by the sheer resolution.These 7 digits are not worth their money, neither on the 2001, nor on the 34470A. A/D linearity, noise, stability do not justify the price over 6 1/2 digit instruments.See also my review/comparison of 34465A vs. 34470A (vs. 3458A).I doubt that the newer instruments already show up on the 2nd hand market, especially for your price suggestion.As the optimized UI of newer instruments is really a big pro, I'd recommend that you think about a 34465A with Digitizing option; 2M memory currently is for free.Frank

author: HighVoltage
author_rank: Super Contributor
timestamp: October 08, 2016, 11:39:08 am
content: Quote from: Echo88 on October 07, 2016, 09:27:07 pmFor 1k€ you will not get a used 34470A nor a well working Keithley 2001.Like Dr.Frank said, look at the 34465AIt is listed at Datatec / Germany for EUR 1.198,00 + MwSt and you might get a discount, if you ask.And keep in mind, that the 34465A will give you an extra digit through the statistics function and throughthe data acquisition software.I even doubt, that you would find a second hand 34465A on the EU market.The 34461A models are showing up from time to time but still with high prices.

author: Echo88
author_rank: Frequent Contributor
timestamp: October 10, 2016, 06:26:38 pm
content: I just finished reading the comparison of the 34465A and 34470A. Really impressive work you did there Frank!So now i think i really will buy a 34465A, including free MEM-update and probably the GPIB-update for datalogging purposes. Gotta read the manual tomorrow for the attainable 7,5 digits.Thanks for all the suggestions, i really appreciate it.

author: VintageNut
author_rank: Frequent Contributor
timestamp: October 10, 2016, 07:41:19 pm
content: I bought a used Keithley model 2000 and had it repaired, calibrated and adjusted with data. The 10VDC and 1VDC ranges were adjusted to within 1ppm of "perfect". This was my best value for performing volt-nut experiments in my office/lab.

author: eponte5
author_rank: Newbie
timestamp: October 11, 2016, 03:10:31 pm
content: Quote from: Berni on October 07, 2016, 12:27:22 pmBut to really use all the digits accurately, wouldn't you have to wait 20 to 30 minutes to let the reference's temperature reach steady state before taking measurements anyways?Don't get me wrong. If you just want to see if you have 3.3V or 5V yeah, 3 seconds of waiting is way better then 20 to 30 seconds. But if you really want to use the 7.5 digits, you have to wait a half hour anyways.Yeah the reason I was asking about features was exactly as you said about the Keysight with graphing capabilities and communication options. I would have thought that is more "featurefull" (sorry for the made up word)

author: VintageNut
author_rank: Frequent Contributor
timestamp: October 11, 2016, 04:21:31 pm
content: DMM7510 is a 90 minute warmup before AutoCal is allowed.

author: Berni
author_rank: Super Contributor
timestamp: October 11, 2016, 05:09:17 pm
content: Quote from: eponte5 on October 11, 2016, 03:10:31 pmYeah they always need a few minutes of warmup to be rock solid and the graphing capabilities tend to be used over long periods of like an hour or even more. But there are uses for lots of digits in relative terms. For example hunting down a annoying power supply short on a large board by testing resistance to narrow it down, or you might look at the voltage of a battery to see if its charging or not. Maybe you are tweaking something and need a good null indicator. Or maybe you are making a non critical measurement that's difficult to do with a cheap multimeter. Like trying to measure a very small current but need the nice low internal resistance of the amps range in order to not mess up the circuit under test.Boot time is not a deal breaker, but it is a factor for me. One of the reasons i like my Agilent MSO6034A scope over the fairly similar in spec and features MSOX3034A (have it at work) is simply because my old scope boots significantly faster. Only other redeeming feature of the new MSOX is wavegen but i have a signal generator. Similar reason why i have a oldschool analog twidly pot PSU next to my digital 3 channel Rigol PSU. Boots faster.I solved the shortcoming of my keithleys lack of advanced features by connecting it to the LAN using a old GPIB to ethernet box(I use it for other GPIB only gear too). Also wrote some graphing software for it that talks to it over LAN to get trend chart like functionality. That graphing software was a bit of a byproduct of some automated testing i was doing with the Keithley(Its more accurate). So with that i mostly taken away the main advantage of my Keysight bench meter, condemning it to mostly gathering dust on the equipment shelf.

author: HighVoltage
author_rank: Super Contributor
timestamp: October 11, 2016, 05:33:53 pm
content: In reality the 34470A and the DMM7510 are about the same in warmup time to read ppm levels.Here are some screen shots of the two units over about 20+ hours, measuring a geller labs SVRT 10V reference.

author: macboy
author_rank: Super Contributor
timestamp: October 12, 2016, 01:02:58 pm
content: Quote from: eponte5 on October 11, 2016, 03:10:31 pmDon't overlook the unusual and useful measurement capabilities of the Keithley 2001/2002. Some of the outstanding capabilities include:- "In-circuit current" measurement that can measure the current (up to 12 A) through almost any conductor, such as a wire or a PCB trace. It does this by alternately measuring the resistance and the voltage across it, then calculating the current.- Temperature measurement that is unrivaled among bench multimeters. It can support virtually any type of thermocouple (J, K, T, E, R, S, B, N) or RTD (PT100, D100, F100, PT385, PT3916) including custom calibrated ones. It uses high order polynomial calculations to translate the sensor reading to temperature at up to 0.001oresolution. This capability in a special purpose instrument could cost more than the entire DMM.- Multiple displayed readings. It has the ability to display (for example) the DC voltage of a power supply along with the AC ripple and frequency of the ripple, very useful for measuring an SMPS output. This is getting less impressive today since more and more instruments can do similar things, but it is a huge step up from a basic one-trick meter like a 34401A, Keithley 2000, or even the venerable 3458A.- Offset compensated Ohms to remove up to 2 V of offset. This is not a given in a bench meter (e.g. 34401A doesn't do it) and 2 V is a large amount of offset to support.

author: Echo88
author_rank: Frequent Contributor
timestamp: October 19, 2016, 04:47:35 pm
content: My 34465A arrived recently and i love itMany thanks to highVoltage and especially Dr. Frank for suggesting the 34465A and providing test results so it was easier to make a decision.I find the histogramm and trend-options very useful, especially since my thermalchamber arrived and i can directly see the cooling speed.Thread can be closed.

author: HighVoltage
author_rank: Super Contributor
timestamp: October 19, 2016, 07:26:28 pm
content: Congratulations on your 34465AWhat kind of thermal chamber do you have?

author: Echo88
author_rank: Frequent Contributor
timestamp: October 19, 2016, 07:48:47 pm
content: A winecooler Acopino BC-48 used as a stable temperature chamber for my measurement stuff. Gonna post some results in the Metrology-section after i have run a few tests.

author: Macbeth
author_rank: Super Contributor
timestamp: October 19, 2016, 08:21:56 pm
content: Quote from: VintageNut on October 10, 2016, 07:41:19 pmI don't believe there is a 1VDC range adjustment on the Keithley 2000. There is a +10V and -10V adjustment for the lower ranges and a +100V adjustment for the 100V & 1000V DC ranges. Of course there is also the 4 way low thermal short adjustment too, that probably helps a bit with the 1V range

author: Macbeth
author_rank: Super Contributor
timestamp: October 19, 2016, 08:52:30 pm
content: Quote from: macboy on October 12, 2016, 01:02:58 pmSeriously? This should put an end to all that burden voltage and having to break a circuit to measure current. Truly outstanding if it works.I have been pretty impressed with the bargain UNI-T 210E for lowish DC currents, but it's a clamp and good for wires only. Great on the car or a PC PSU for example.How well does this 2001/2002 feature work in reality with PCB traces? Does it need 4 wire mode for the very low resistance? How does it measure resistance anyway with a powered on circuit?

author: TiN
author_rank: Super Contributor
timestamp: October 20, 2016, 04:23:33 am
content: MacbethIt works, but accuracy and noise is rather poor. It requires 4W kelvin connection at all times.Common mode voltage (if it's below meter's spec) is rejected by isolation.QuoteYes, but that requires CJC scanner board, TC-SCAN2001, which is at least 200-400$ on ebay...RTDs can be used directly though.

author: Berni
author_rank: Super Contributor
timestamp: October 20, 2016, 05:29:30 am
content: Quote from: Macbeth on October 19, 2016, 08:52:30 pmI have not tried mine on PCB traces yet, but it is designed to have some voltage compliance with resistance testing. I need to give it a try when i get home, still i assume you need a proper kelvin connection on the trace it self for it to show any reasonable value.Some keysight handheld meters have a feature specifically designed for testing resistance with voltage present for testing cable runs with current in them or ground wires that run along energized mains cables (I forgot up to what voltage it works).Quote from: TiN on October 20, 2016, 04:23:33 amNo need for the scanner board if you only want to connect a single thermocouple. Just stick it in to the volts jacks over a thermocouple to banana adapter. I used it before for this. Only thing is that you don't get any cold junction compensation so it will show 0°C at room temperature of simply sum in whatever room temperature you set in the menu. Its not possible to properly do compensation when using that banana adapter anyway as the cold junction is in there.

author: macboy
author_rank: Super Contributor
timestamp: October 20, 2016, 06:38:45 pm
content: Quote from: Berni on October 20, 2016, 05:29:30 amAn alternative is to use two identical thermocouples, with the copper sides facing the banana jacks and the 'exotic' metal sides connected together. Now you insert one into a stirred ice bath, and measure with the other. This gives you proper cold junction compensation that is far better than the estimated one used on the TSCAN card, which uses a single digital temp sensor chip to estimate cold junction temperature of all 9 cold junctions on the card.Using a single front-panel connected thermocouple and zeroing the reading using an ice bath is probably even better than what the TSCAN card does, as long as you understand that changes in ambient temperature directly influence the reading until the next zeroing.I have a scanner card, a 10 channel general purpose one, not the 9 channel TSCAN. With the 10 channel card, you can do the ice bath on channel 1 and super-accurate automatically-compensated measurements on the other 9 channels.

author: Macbeth
author_rank: Super Contributor
timestamp: October 20, 2016, 07:52:40 pm
content: Quote from: macboy on October 20, 2016, 06:38:45 pmI believe the ice bath method is used for calibrating the TCSCAN, but is not very practical in real world use, at least with logging stuff unattended.The TCSCAN temp sensor is not digital but an analog transducer AD590M which is also quite pricey. I quite fancy making a cheap TCSCAN card of my own, perhaps replacing the hard to find 5841 serial latched driver logic with an 8 bit micro and using a much cheaper and more accurate AD592C for the CJC?As an aside, one of the big sells of the RIGOL DM3058E I have is that it has a user-defined sensor mode, complete with CJC for thermocouples and has profiles for all the common ones built in. This is great you would think, only there is noofficialway of actually reading these using SCPI!Even RIGOLs own DM3058 proprietary and expensive meter control/logging software does everything, volts, amps, frequency, capacitance, dual display... but the sensor function is greyed out!I do wonder what they use for the CJC? I think I need to tear it apart again

author: TiN
author_rank: Super Contributor
timestamp: October 20, 2016, 09:42:06 pm
content: TCSCAN card also has copper slug on bottom side to equalize temperature better over terminals.For my use I just ditched TCs and used Honeywell HEL Pt1000 RTD instead. No CJC voodoo needed

author: Macbeth
author_rank: Super Contributor
timestamp: October 20, 2016, 10:04:50 pm
content: Quote from: TiN on October 20, 2016, 09:42:06 pmI did wonder about that "COPPER ISOTHERMAL BLOCK" (copper slug), I've never seen a picture of it but it seems fairly obvious how it would be arranged. I would be happy with just having CH1 and CH2 for the CJC and the temp sensor and all the other channels for voltage readings.But a BME280 is better than any of that stuff anyway.