EEVBlog forum’s member Inverted18650 offered a set of neat Caddock resistors to try for stability and temperature coefficient measurement database. No need to invite twice, so here we are with the loot:
| Resistor | Value | Tempco spec | Number | Reference | Measured tempco | Datalog chart |
|---|---|---|---|---|---|---|
| Caddock TF020R | 1 kΩ | ± 5 ppm/°C | 12 | 3458A | -0.96 ppm/K |  |
| Caddock TF020R | 9 kΩ | ± 5 ppm/°C | 9 | 3458B | +2.18 ppm/K | |
| Caddock TF020R | 20 kΩ | ± 5 ppm/°C | 7 | 2002-6 | -2.26 ppm/K | |
| Caddock TF020R | 5 kΩ | ± 5 ppm/°C | 10 | 3458A | +2.99 ppm/K |  |
| Caddock TF020R | 100 kΩ | ± 5 ppm/°C | 1A | 3458B | +1.71 ppm/K | |
| Caddock TF020R | 18 kΩ | ± 5 ppm/°C | 8 | 2002-4 | +3.59 ppm/K | |
| Caddock TF020R | 200 kΩ | ± 5 ppm/°C | 2 | 2002-6 | +3.20 ppm/K | |
| Caddock TF020R | 24 kΩ | ± 5 ppm/°C | 5 | 3458A | -1.28 ppm/K |  |
| Caddock TF020R | 100 kΩ | ± 5 ppm/°C | 1E | 3458B | +0.74 ppm/K | |
| Caddock TF020R | 22 kΩ | ± 5 ppm/°C | 6 | 2002-4 | +3.80 ppm/K | |
| Caddock TF020R | 100 kΩ | ± 5 ppm/°C | 1D | 2002-6 | +2.75 ppm/K | |
| Caddock TF020R | 500 kΩ | ± 5 ppm/°C | 3 | 3458A | -1.82 ppm/K |  |
| Caddock TF020R | 25 kΩ | ± 5 ppm/°C | 4B | 3458B | -0.74 ppm/K | |
| Caddock TF020R | 100 kΩ | ± 5 ppm/°C | 1B | 2002-4 | +4.09 ppm/K | |
| Caddock TF020R | 25 kΩ | ± 5 ppm/°C | 4A | 2002-6 | -0.40 ppm/K | |
| Caddock MK120 | 100 Ω | ± 50 ppm/°C | 11A | 3458A | -3.43 ppm/K (box, non-linear) |  |
| Caddock MK120 | 100 Ω | ± 50 ppm/°C | 11B | 3458B | -4.85 ppm/K (box, non-linear) | |
| Caddock TF020R | 100 kΩ | ± 5 ppm/°C | 1C | 2002-4 | -1.43 ppm/K | |
| Resistor 7+9 series | 29 kΩ | Combined | 2002-6 | -0.77 ppm/K |
These will take some 60-120 hours of my four 8½-digit DMMs to get all data collected. And as good excuse, I got myself new PTFE silver-plated copper kelvin cable to build some fixtures.
This is nice cable, fully shielded and robust to use. I’ll be making multiple variants, using both Pomona 5406, Pomona 4892 banana jacks (which have BeCu spring contacts) for meters like Keithley 2002 and Advantest R6581T. Best performance cables will also have bare-copper spade lugs for proper connections on devices like Keysight 3458A and Fluke 5700A.
Each cable is Kelvin-connected, with four separate conductors to utilize highest precision of the benchtop meters.
I also want to try alternative idea with reverse-connected spade lug as thermal anchor for DUT-resistor mount.
-==================================================================================================¬ ¦ xDevs.com TEC Experiment kit -i- Datafile teckit_caddock_test1.csv exists ¦ +--------------------------------------------------------------------------------------------------+ ¦ GPIB[25] : Keithley 2510 ¦ ¦ GPIB[ 2] : Keysight 3458 ¦ ¦ GPIB[ 6] : Keithley 2002 ¦ ¦ GPIB[ 3] : Keysight 3458 ¦ ¦==================================================================================================¦ ¦ Sample : 169 Meter mode : OHMFO Set Temp : 20.000 °C ¦ ¦ Next temp : 20.000 °C Measured val : 999.97864710 Process Temp : 19.997 °C ¦ ¦ Min temp : 20.000 °C OCOMP/DELAY : 1, 0 sec TEC Current : -0.3215 A ¦ ¦ Peak temp : 50.000 °C Fixed range : Configure Status : Hold start ¦ ¦ Remaining : 8h 25m 38s NPLC : 100.0000 Gain : 140.0000 ¦ ¦ Elapsed time : 0h 12m 09s Terminals : FRONT Intergal : 0.1000 ¦ ¦ Progress : 2.35% REL Value : 1E-06 Derivative : 0.9000 ¦ ¦ ¦ ¦ ¦ ¦ [ 154] : S = 20.000 P = 19.998 I = -0.325 A VAL = 999.9787099 R, PCB_T = 9004.961776 R ¦ ¦ [ 155] : S = 20.000 P = 19.998 I = -0.325 A VAL = 999.9786758 R, PCB_T = 9004.962009 R ¦ ¦ [ 156] : S = 20.000 P = 19.998 I = -0.325 A VAL = 999.9786614 R, PCB_T = 9004.961039 R ¦ ¦ [ 157] : S = 20.000 P = 19.998 I = -0.324 A VAL = 999.9788573 R, PCB_T = 9004.960913 R ¦ ¦ [ 158] : S = 20.000 P = 19.998 I = -0.325 A VAL = 999.9787782 R, PCB_T = 9004.962207 R ¦ ¦ [ 159] : S = 20.000 P = 19.998 I = -0.324 A VAL = 999.9788177 R, PCB_T = 9004.962189 R ¦ ¦ [ 160] : S = 20.000 P = 19.998 I = -0.325 A VAL = 999.9787513 R, PCB_T = 9004.962279 R ¦ ¦ [ 161] : S = 20.000 P = 19.997 I = -0.323 A VAL = 999.9787818 R, PCB_T = 9004.962818 R ¦ ¦ [ 162] : S = 20.000 P = 19.998 I = -0.323 A VAL = 999.9787387 R, PCB_T = 9004.962261 R ¦ ¦ [ 163] : S = 20.000 P = 19.999 I = -0.324 A VAL = 999.9786758 R, PCB_T = 9004.961362 R ¦ ¦ [ 164] : S = 20.000 P = 19.997 I = -0.323 A VAL = 999.9787926 R, PCB_T = 9004.958721 R ¦ ¦ [ 165] : S = 20.000 P = 19.998 I = -0.322 A VAL = 999.9787908 R, PCB_T = 9004.959080 R ¦ ¦ [ 166] : S = 20.000 P = 19.997 I = -0.323 A VAL = 999.9787692 R, PCB_T = 9004.959835 R ¦ ¦ [ 167] : S = 20.000 P = 19.997 I = -0.321 A VAL = 999.9788537 R, PCB_T = 9004.960769 R ¦ ¦ [ 168] : S = 20.000 P = 19.997 I = -0.321 A VAL = 999.9787261 R, PCB_T = 9004.960572 R ¦ ¦ [ 169] : S = 20.000 P = 19.997 I = -0.321 A VAL = 999.9786471 R, PCB_T = 9004.959278 R ¦ ¦ [ 148] : S = 20.000 P = 19.997 I = -0.326 A VAL = 999.9786524 R, PCB_T = 9004.960661 R ¦ ¦ [ 149] : S = 20.000 P = 19.998 I = -0.326 A VAL = 999.9787800 R, PCB_T = 9004.959871 R ¦ ¦ [ 150] : S = 20.000 P = 19.998 I = -0.326 A VAL = 999.9789022 R, PCB_T = 9004.960769 R ¦ ¦ [ 151] : S = 20.000 P = 19.998 I = -0.326 A VAL = 999.9788788 R, PCB_T = 9004.960715 R ¦ ¦ [ 152] : S = 20.000 P = 19.997 I = -0.325 A VAL = 999.9786363 R, PCB_T = 9004.962513 R ¦ ¦ [ 153] : S = 20.000 P = 19.997 I = -0.325 A VAL = 999.9787584 R, PCB_T = 9004.961416 R ¦ ¦==================================================================================================¦ ¦ REF : 999.9615 Delta : 17.148 ppm ¦ ¦ L========================================= -21.623==============================================-
Test in progress, as in TECKit UI app.
Here are same resistor set results, but sorted per tempco value.
| Resistor | Value | Tempco spec | Number | Measured tempco |
|---|---|---|---|---|
| Caddock TF020R | 100 kΩ | ± 5 ppm/°C | 1B | +4.09 ppm/K |
| Caddock TF020R | 22 kΩ | ± 5 ppm/°C | 6 | +3.80 ppm/K |
| Caddock TF020R | 18 kΩ | ± 5 ppm/°C | 8 | +3.59 ppm/K |
| Caddock TF020R | 200 kΩ | ± 5 ppm/°C | 2 | +3.20 ppm/K |
| Caddock TF020R | 5 kΩ | ± 5 ppm/°C | 10 | +2.99 ppm/K |
| Caddock TF020R | 100 kΩ | ± 5 ppm/°C | 1D | +2.75 ppm/K |
| Caddock TF020R | 9 kΩ | ± 5 ppm/°C | 9 | +2.18 ppm/K |
| Caddock TF020R | 100 kΩ | ± 5 ppm/°C | 1A | +1.71 ppm/K |
| Caddock TF020R | 100 kΩ | ± 5 ppm/°C | 1E | +0.74 ppm/K |
| Caddock TF020R | 25 kΩ | ± 5 ppm/°C | 4A | -0.40 ppm/K |
| Caddock TF020R | 25 kΩ | ± 5 ppm/°C | 4B | -0.74 ppm/K |
| Resistor 7+9 series | 29 kΩ | Combined | -0.77 ppm/K | |
| Caddock TF020R | 1 kΩ | ± 5 ppm/°C | 12 | -0.96 ppm/K |
| Caddock TF020R | 24 kΩ | ± 5 ppm/°C | 5 | -1.28 ppm/K |
| Caddock TF020R | 100 kΩ | ± 5 ppm/°C | 1C | -1.43 ppm/K |
| Caddock TF020R | 500 kΩ | ± 5 ppm/°C | 3 | -1.82 ppm/K |
| Caddock TF020R | 20 kΩ | ± 5 ppm/°C | 7 | -2.26 ppm/K |
| Caddock MK120 | 100 Ω | ± 50 ppm/°C | 11A | -3.43 ppm/K (box, non-linear) |
| Caddock MK120 | 100 Ω | ± 50 ppm/°C | 11B | -4.85 ppm/K (box, non-linear) |
If you want to run own analysis on the captured data, here are the raw data DSV-files:
Created: March 8, 2018, 5:25 p.m.
Modified: April 8, 2020, 5:53 a.m.
Modified: April 8, 2020, 5:53 a.m.