New Agilent 34461A 6.5 Digit Bench Multimeter

[KedasProbe]

Seeing/getting that extra digit does matter for me (at 100PLC), I will decide what is useful and what isn't: see example:
The exported csv of the DM3068 is giving what the 34461A is displaying (the left column)

[Zucca]

Just discovered a new FW 1.10 released on the 2014-06-20, seems like a minor update

http://www.home.agilent.com/agilent/software.jspx?ckey=2367633&lc=eng&cc=US&nid=-536902435.1058513&id=2367633

in attachment the release note... so a failed SELF TEST 34461a unit with FW 1.09, could be easily fixed by the FW 1.10? Ebay buyer be aware!  O0

[VK5RC]

Doesn't the update fix the current potential problem  of a false report of failed ac offset testing ie not failed ,  but from the update a repeat test would declare if a true fault existed? 
eBay buyers may get a bargain of a 'as is'  failed self test 344601, then  update the f-ware and have an on specification machine! 

[neslekkim]

Interresting that Agilent doesn't bother to send out info about new firmware or other software revisions at all, especially since I have registered my unit on their site.. 

[engineer_in_shorts]

Interresting that Agilent doesn't bother to send out info about new firmware or other software revisions at all, especially since I have registered my unit on their site.. 

Stops them being bombarded with support questions following unnecessary upgrades... a lot of customers may not be affected/require the update.

[BVH]

I’ve been looking at specs and video reviews on 6 ½ digit DMMs for the last 4 days.  I don’t “need” a 6.5 digit meter but I am very interested in electrical and electronics and I “want” one.  Some background.  I’m 61, retired and my most enjoyable hobby is finding, acquiring and repairing older 1960’s – 1980’s vintage military long-range Short Arc searchlights and modern day aviation Short Arc searchlights.   These lights produce laser-like beams down to 1 degree and project that beam for 2+ miles – much further than the unaided eye can see.  As such, I do some basic troubleshooting, parts testing and replacement and re-wiring on the lights themselves and on the short arc power supplies including their 35KV to 45KV ignition systems.  I also enjoy finding “for parts” variable DC power supplies and trying to repair them.

I want a bench meter capable of absolute 3-decimal place accuracy.  When performing the posted accuracy calculation for the Fluke 8846A and the Agilent 34461A, my net results show that even when using the 1-year maximum error percentage factors, the result will not impact the 1st, 2nd & 3rd Decimal digits.   Is this correct?

I’ve tentatively narrowed my search to the Fluke 8846A, the Agilent 34410A or the 34461A.  From what I can see, the Fluke is capable of a bit better accuracy over the Agilent 34461A but I love the tft screen on the Agilent and if it can give me that guaranteed 3-place accuracy, then I would lean towards that meter.  The software for the Agilent units also seems to be much more user-friendly and feature-rich when used on a PC.

I’m guessing that any of these units would be very much overkill for my novice needs but all the same, I would appreciate thoughts and opinions as I enjoy hearing what others with much more experience have to say.  Thank you in advance.

[robrenz]

I am a BIG 8846A fanboy and IF you need the extra ppms and ranges/features it provides you will be very happy.

But I suggest you buy the 34461A because the user interface, graphing/charting capabilities and software are much nicer than the 8846A.

I am very glad I bought a 8846A but my second meter would be a 34461A. That is until Keithley comes out with their new 6.5 digit meter with a interface similar to the 2450 SMU

[BVH]

Will the Keithley be out any time soon and are its specs supposed to be similar to the Fluke or Agilent?  Any links to speculation threads?

Being a novice, I certainly know the Fluke and HP Agilent names but am not familiar with Keithley.  I assume it's on the same level (subject to differing personal opinions, of course)?

Is price point going to be similar?

[robrenz]

No idea on the time frame but I am pretty sure it is being worked on as we speak.

[BVH]

Is the 2x4 wire resistance measurement system that Fluke touts unique to their meters or can the Agilent do the same using the Fluke 2x4 special lead set?

[robrenz]

AFIK it is a Fluke only feature.

[engineer_in_shorts]

Is the 2x4 wire resistance measurement system that Fluke touts unique to their meters or can the Agilent do the same using the Fluke 2x4 special lead set?

2x4 wire resistance is only a feature to try and reduce the clutter on your desk by having a lead set that can do voltage measurements as well as 4 wire resistance measurements.  Personally i do not like the idea as you have to purchase specially made 4 wire leads from fluke.  I prefer to make my own test harnesses most of the time.

[engineer_in_shorts]

I want a bench meter capable of absolute 3-decimal place accuracy.  When performing the posted accuracy calculation for the Fluke 8846A and the Agilent 34461A, my net results show that even when using the 1-year maximum error percentage factors, the result will not impact the 1st, 2nd & 3rd Decimal digits.   Is this correct?

Numbers of decimal digits is hard to give an answer for since we do not know how big the values are you are measuring.  At hundreds of volts you have three digits before the decimal place!
Usually the places to watch out (lowest accuracy) are AC voltage on extremes of the frequency range, and AC current.  For example the Agilent (now keysight  ) AC voltage above 100kHz is 4%.

Also understand the difference between resolution, the manufacturer stated accuracy, and the total uncertainty of measurement.

This is a good read:
http://cp.literature.agilent.com/litweb/pdf/5989-4879EN.pdf

and same from fluke
http://support.fluke.com/calibration-sales/Download/Asset/2547797_6200_ENG_A_W.PDF

[EEVblog]

Is price point going to be similar?

It would have to be to compete, but Keithley have never been in that game of chasing the bottom market.
Agilent were very aggressive on the pricing for the 34461A, and I wouldn't expect Keithley to match it.

[BVH]

Numbers of decimal digits is hard to give an answer for since we do not know how big the values are you are measuring.  At hundreds of volts you have three digits before the decimal place!
Usually the places to watch out (lowest accuracy) are AC voltage on extremes of the frequency range, and AC current.  For example the Agilent (now keysight  ) AC voltage above 100kHz is 4%.

Also understand the difference between resolution, the manufacturer stated accuracy, and the total uncertainty of measurement.

This is a good read:
http://cp.literature.agilent.com/litweb/pdf/5989-4879EN.pdf

and same from fluke
http://support.fluke.com/calibration-sales/Download/Asset/2547797_6200_ENG_A_W.PDF

Good points.  98% or more of my work is with 36 VDC & below and 100 Amps & below (I have other meters for the Amps work).  With Series configured batteries and their balanced charging systems, I get into double-digit mAh measurements.  I think I have a good handle on accuracy and resolution.  Resolution being the number of places to the right of the Decimal a meter can resolve down to and accuracy being how much higher and lower the true measurement can be as compared to the display reading.  I'll go have a read at the links.  Thanks.

I'm not in a real hurry but I am excited to get something to work/play with.  Paying a few hundred bucks more is not a huge barrier for this purchase so if the Keithley was a month or two out and near the cost of the Fluke 8846A, I could probably control myself long enough to see how its' specs, screen and PC software compare.  Is there any idea floating around in how far out it might be?

[Sparky]

As an update to earlier discussions about programs to continuously stream measurements from the 34461A to a PC, I updated and cleaned up some Agilent MATLAB scripts.  I've attached two files: one is the main script to setup the DMM and read out measurements, the other is a simple helper script to check the DMM for errors.

The code is set to read 100000 measurements, and it does so by reading 2000 sets of 50 measurements each.  On my PC, the MATLAB output is:

Code: [Select]

Data remaining  : 0
Time elapsed    : 90.909 sec
Acquisition rate: 1100.0006 samples/sec
Indicating the 100000 samples were acquired in just over 90 sec.

I might make a graphical interface with controls to adjust the # samples, etc.  If so, I'll post it here. 

Cheers!

[rodpp]

As an update to earlier discussions about programs to continuously stream measurements from the 34461A to a PC, I updated and cleaned up some Agilent MATLAB scripts.  I've attached two files: one is the main script to setup the DMM and read out measurements, the other is a simple helper script to check the DMM for errors.

The code is set to read 100000 measurements, and it does so by reading 2000 sets of 50 measurements each.  On my PC, the MATLAB output is:

Code: [Select]

Data remaining  : 0
Time elapsed    : 90.909 sec
Acquisition rate: 1100.0006 samples/sec
Indicating the 100000 samples were acquired in just over 90 sec.

I might make a graphical interface with controls to adjust the # samples, etc.  If so, I'll post it here. 

Cheers!

Thank you for share your work.

It is helpful to have a code example from start, it will be very useful.

Here is the result in my computer:

Code: [Select]

Data remaining  : 0
Time elapsed    : 90.8939 sec
Acquisition rate: 1100.1841 samples/sec


[Sparky]

Thank you for share your work.

It is helpful to have a code example from start, it will be very useful.

Here is the result in my computer:

Code: [Select]

Data remaining  : 0
Time elapsed    : 90.8939 sec
Acquisition rate: 1100.1841 samples/sec


Thank you for the comment rodpp!  I'm glad to know someone was able to use the MATLAB code -- I hope it proves a good starting point and easy to modify.  I am using the script often so I will probably make a GUI for it.

Cheers!

[BVH]

Can my 34461A measure the Internal Resistance of my Lithium Polymer RC battery cells using my 4-wire Kelvin probes without being damaged by the approximate 4.2 VDC contained in the cells?  Typical resistance in good cells is between 1.5 and 5.0 mOhms.

[LabSpokane]

Can my 34461A measure the Internal Resistance of my Lithium Polymer RC battery cells using my 4-wire Kelvin probes without being damaged by the approximate 4.2 VDC contained in the cells?  Typical resistance in good cells is between 1.5 and 5.0 mOhms.

Why not use the 4 wire leads on an external current shunt? 

[MarkPalmer]

I see everyone in the TE business is jumping on the color TFT bandwagon in very short order for just about everything.  Reason being the displays are just so nice and pleasant to read!  I got my first one on an Applent LCR meter and after using it I don’t like other antiquated displays too much, especially monochrome LCD’s. (Ok, still a place in heart for nixies and red LED’s..)  But I never cared for those green VFD’s- they remind me too much of 1970’s Unisonic calculators and after a few years, they all start to get dim.     

-Mark-

[LabSpokane]

I see everyone in the TE business is jumping on the color TFT bandwagon in very short order for just about everything.  Reason being the displays are just so nice and pleasant to read!  I got my first one on an Applent LCR meter and after using it I don’t like other antiquated displays too much, especially monochrome LCD’s. (Ok, still a place in heart for nixies and red LED’s..)  But I never cared for those green VFD’s- they remind me too much of 1970’s Unisonic calculators and after a few years, they all start to get dim.     

-Mark-

I can sum up the 34461A display in a word: brilliant. I read all the nonsense and angst over the meter here. Any worries about the meter only matter on the internet. In person, it's just fantastic and the display is a huge improvement. I love the charting feature. I just wish that it would save directly to the USB stick and time stamp the readings. Those are minor gripes for something so well executed.

By the way, when I ordered, disty was backordered 2 months. It's very popular. I had to get one just because the pair of 34401s I had in my work lab were so useful.

[BVH]

Yesterday, I was making up some #4 AWG cables for one of my tank lights.  It's a soldered joint.  For this size cable, I use a micro torch because my 50 watt Hakko station just doesn't cut it.  I filled the contact solder cup with just the right amount of solder.  I then used a bit of liquid flux on the bare cable and used my homemade solder pot to tin the 5/8" length of bare cable.  With the contact in my vice squeezed by wood blocks, I re-heated the contact cup and slowly dipped the tinned cable into the cup - and kept the torch on the contact for about 5 seconds to allow the cable to heat up properly.   

I've never had a quality Ohm meter so I've never tested any of my joints.  So I tested this one using the 2-wire probes.  I was surprised and disappointed to see 0.033 Ohms measured from a bit of bare cable behind the joint and the contact rubbing surface - about 1 1/2" total length.  I was in Auto Scale and Auto Zero.   I thought about this last night and was feeling pretty bad about my soldering abilities.  Today, I remembered that I didn't do a "zeroing" of the probes before I took my measurements.  So I fired up the meter, punched in 2-wire Ohms and put the probes together and got a .030 reading.  I then realized I didn't know how to zero the meter. So I thought that the Null function might do the trick.  I went through this and ended up getting .0000 when the probes were touched together.  Then I measured my joint but this time, including 9' of cable and got a between 0.009 and 0.010 Ohms.  But I really don't know if the Null function is what I should be doing or if the "Auto Zero" function is already taking care of zeroing the meter.  But if so, then why do I get 0.030 when touching the probes together?

I tried reading about this in the manual but just can't seem to understand what the below paragraph from the manual is telling me.

Step 5: Specify whether you want to use Auto Zero. Autozero provides the most accurate measurements, but
requires additional time to perform the zero measurement. Note that there is no autozero setting for 4-wire resistance
measurements.
With autozero enabled, the DMM internally measures the offset following each measurement. It then subtracts that
measurement from the preceding reading. This prevents offset voltages present on the DMM’s input circuitry from
affecting measurement accuracy. With autozero disabled, the DMM measures the offset once and subtracts the offset
from all subsequent measurements. The DMM takes a new offset measurement each time you change the function,
range, or integration time.


Can someone tell me the proper setup and procedure to take a 2-wire Ohm measurement with this meter?  Maybe with and without Auto Zero enabled?

[Rufus]

Can someone tell me the proper setup and procedure to take a 2-wire Ohm measurement with this meter?  Maybe with and without Auto Zero enabled?

The auto zero is compensating for errors in the meter internal circuitry, nothing to do with external measurements you are making.

2 wire Ohm measurement of a few milliohms is almost pointless. Read up on 4 wire measurements or for a chunky connection like that stick a few amps through it from a bench supply and probe the voltage across it. 

[BVH]

Got a set of Agilent 4-wire Kelvin leads and re-measured.  .009 Ohms - and this was with almost 10' of the #4 AWG cable in the measurement.  Much happier now.