Login Join Maker Pro
Or sign in with

# Ye olde Fluke

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
I just received my 0.005% 10k resistor and my 0.01% 100 ohm resistors today.

I bought them to set up a poor man's resistance standard to test my meters.

My 1979 vintage Fluke 8375A (that I also got the manual for today) reads the 10k resistor as 9997.7 ohms, and the 100 ohm resistor as 100.020 ohms.

I didn't let it warm up (the calibration procedure says leave it for an hour) so it's still turned on and I'll see what it reads later.

I'm using the resistance probes I built myself (it's not rocket science).

I believe the meter was last calibrated in the late 1990's so it's well overdue. I don't have the equipment to do it myself, and the meter cost only a little more than the resistors.

I'll be happy knowing approximately how (in)accurate it is.

I also have a precision 10V reference (well, as precision as you can get for $10) that I'm going to build up inside an oven (maybe). For$10 you can't get really good temperature stability, so, I'll keep the temperature constant

The manual is really a blast from the past. It includes full calibration procedures, schematics, and fault finding guides. It also lists all the HP equipment you need to calibrate it

OK, so currently the 10K range is reading about 0.02% low and the 100 ohm range is about 0.02% high I'm happy so far. The specs say 0.05% for the 10K range and 0.01% for the other ranges.

It's been on for a while now and it's drifting up maybe 1 or 2 counts in the least significant digit.

#### Harald Kapp

##### Moderator
Moderator
Nov 17, 2011
12,613
Steve, 0.02% for a 33 year old multimeter sounds goooood.

Personally I don't think I'd try to calibrate the thing out of fear of making things worse. I work with 1% resistors, rarely 0.1% ones, so the mutlimeter would (at 0.02%) still be almost an order of magnitude more accurate than my components.

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
You should hear it auto-range.

It's full of relays and nixie tubes (not that you can hear nixie tubes).

It will be fun just to spend some time looking at the schematic to see how it was done with discrete components. Would you believe the logic is all DTL!!! Wow.

The parts list doesn't give part numbers unfortunately. Not a real issue with passive components, but more so with transistors.

Do you want a real laugh? Look here.

#### Harald Kapp

##### Moderator
Moderator
Nov 17, 2011
12,613
Wow!
Keep a sharp eye on your's.

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
Yeah, that price is a very large case of wishful thinking.

N
Replies
1
Views
960
Andrew Holme
A
A
Replies
5
Views
928
A
S
Replies
13
Views
2K
Fred Bloggs
F
Replies
8
Views
416
Replies
11
Views
847