Author Topic: Teardown : ESI DB52 resistance decade check  (Read 2669 times)

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Offline TiN

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Teardown : ESI DB52 resistance decade check
« on: April 15, 2015, 03:46:53 am »
RAWR, precision-nuts.



Since I got 60% (3 from 5) of my 2001 meters repaired and ready for calibration, its time to get some resistance box. And as I already have some foils in main values, addition of more fine decade resistor was wanted.

I had no intention to spend big money, it is also my first ever decade box, so end up winning this ESI 5-decade resistor for a 95$ excluding shipping. Seller state it was good and calibrated January 2013.







It is dirty and little rusty outside, but that is fine if the thing performs well.

Don't turn it on, take it apaaart :)







That is well and robust construction, but switches are not as fancy as in higher grade decades, which I saw on web review before.

There are no trimpots or jumpers elsewhere, how does such resistance decades are usually calibrated?
« Last Edit: April 15, 2015, 10:38:28 pm by TiN »
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Offline TiN

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Re: Teardown : ESI DB52 resistance decade check
« Reply #1 on: April 15, 2015, 03:52:43 am »
Performance and verification

I had two meters to check this DB52 :

Agilent 34970A with 34901A mux card, in 4W ohms mode, 200NPLC (Calibrated in 2013)
Keithley 2001 , 4W ohms with offset compensation, 10NPLC (Calibrated February 2014).

Not to jam thread with gazillion of photos, here are thumbnails.



First connect meter 4W to ESI decade. Set all decades to zero.
Null meter using offset(relative) function. This will be our zero reference.

Adjust decades, measure resistance.







I am impressed as for it's money. Definately a keeper unit.

Will use this box for KX project circuits tests, such as ADC, DACs and current sources.
« Last Edit: April 15, 2015, 04:45:30 am by TiN »
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Offline TiN

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Re: Teardown : ESI DB52 resistance decade check
« Reply #2 on: April 15, 2015, 03:53:37 am »
Measured accuracy for all decades (by 34970A)

--      1E1            1E2            1E3            1E4            1E5           
00    0.00007 Ohm   0.00007 Ohm   0.00038 Ohm   0.02559 Ohm   1.93515 Ohm         
01   10.00067 Ohm 99.99229 Ohm 999.93156 Ohm 9999.91797 Ohm 100001.12500 Ohm     
02   19.99982 Ohm 200.00353 Ohm 1999.89009 Ohm 19999.94097 Ohm 200016.91667 Ohm   
03   29.99740 Ohm 300.00983 Ohm 2999.82813 Ohm 30000.11719 Ohm 300011.90625 Ohm   
04   40.00387 Ohm 400.01471 Ohm 3999.79818 Ohm 40000.22656 Ohm 400014.12500 Ohm   
05   49.99859 Ohm 500.02953 Ohm 4999.77409 Ohm 50000.20313 Ohm 500017.66667 Ohm   
06   59.99515 Ohm 600.03055 Ohm 5999.70898 Ohm 59999.72396 Ohm 600026.75000 Ohm   
07   69.99643 Ohm 700.03494 Ohm 6999.64355 Ohm 70000.16667 Ohm 700028.00000 Ohm   
08   79.99512 Ohm 800.04053 Ohm 7999.60482 Ohm 80000.16667 Ohm 800028.50000 Ohm   
09   89.99380 Ohm 900.04500 Ohm 8999.57552 Ohm 90000.13542 Ohm 900032.16667 Ohm   
10   99.99229 Ohm 999.93156 Ohm 9999.91797 Ohm 100001.12500 Ohm 1000029.60000 Ohm

--      1E1            1E2            1E3            1E4            1E5       
00   Invalid data  Invalid data  Invalid data  Invalid data  Invalid data 
01      67.043 ppm    -77.133 ppm    -68.420 ppm     -8.203 ppm     11.250 ppm
02      -8.965 ppm     17.624 ppm    -54.932 ppm     -2.930 ppm     84.609 ppm
03     -86.594 ppm     32.756 ppm    -57.292 ppm      3.906 ppm     39.688 ppm
04      96.703 ppm     36.774 ppm    -50.476 ppm      5.664 ppm     35.313 ppm
05     -28.305 ppm     59.082 ppm    -45.215 ppm      4.063 ppm     35.313 ppm
06     -80.808 ppm     50.964 ppm    -48.503 ppm     -4.622 ppm     44.583 ppm
07     -51.008 ppm     49.874 ppm    -50.921 ppm      2.344 ppm     40.000 ppm
08     -61.035 ppm     50.659 ppm    -49.377 ppm      2.051 ppm     35.625 ppm
09     -68.834 ppm     49.981 ppm    -47.201 ppm      1.476 ppm     35.764 ppm
10     -77.133 ppm    -68.420 ppm     -8.203 ppm     11.250 ppm     29.625 ppm

Attached dirty spaghetti code to calculate ppm table from raw data samples.
« Last Edit: April 15, 2015, 02:56:18 pm by TiN »
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Online Vgkid

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Re: Teardown : ESI DB52 resistance decade check
« Reply #3 on: April 15, 2015, 04:43:16 am »
Nice score, I picked up a DB62 last year for 80tot, and a DB655 for 30tot(still need to put it back together).
I noticed my DB62 is pretty stable, my favorite test is to set all dials to '2', and my 3456 reads '222,225' though sometimes it reads 222,222 :D
If you own any North Hills Electronics gear, message me. L&N Fan
 

Offline TiN

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Re: Teardown : ESI DB52 resistance decade check
« Reply #4 on: April 15, 2015, 02:57:14 pm »
Added decade tolerance data in third post, based on 34970A measurements.

Don't shoot for code.  :palm:
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