Products > Test Equipment
Easy way to test the calibration of a DMM (Fluke 45)?
<< < (29/29)
Fried Chicken:
Resistors:

For the (presumably, I didn't read it) 470Ω resistor:
Hioki: 470.7Ω
Fluke: 469.9Ω

Hioki:



Fluke:



For the (again presumably) 1kΩ resistor:
Hioki: 0.998kΩ
Fluke 0.9973kΩ

Hioki:



Fluke:



And finally a (presumably) 220Ω Resistor (I just randomly grabbed these out of my misc. can of electronic stuff):

Hioki: 220.0Ω
Fluke: 219.61Ω

Hioki:



Fluke:




I have to say in doing all of this, it feels really weird to not trust the Hioki and instead trust this new (to me) Fluke.  The Hioki has been my companion for everything, being my only multimeter after someone stole my cheap-o craftsman (still angry/sad about this one).  The Hioki has this very endearing way of beeping at you when taking measurements.  It's also very fast, and been rock solid reliable whenever I've used it.  It's a weird thought to think that this Fluke 45 is now presumably my gold standard and I should trust it over my Hioki.  That said, after finding out about Hioki's after sales support/information including service manuals (it pretty much doesn't exist), I can't really recommend Hioki anymore.  That is a damn shame but oh well.
Fried Chicken:
Frequency Counting

So now I gt to dicking with the frequency generator that I bought along with the Fluke 45, and trying out the Fluke's frequency counting capabilities.

It's a BK Precision 4040 (no 4040A, 4040B or anything, just the 4040).  This must be a pretty old unit, b/c I had a very hard time finding any information on it online.

The frequency generator's display and the Fluke are almost perfectly bang on all the way up to about 2.3MHz-ish on the Fluke that then got pissy and stopped reporting accurately.  This might have been b/c the signal became too weak, but when I hooked it up to the scope, I saw an appropriate p2p voltage, so I'm guessing it's just out of range for the Fluke?

Here is 10.004kHz:



And then at 1.6603MHz.  The scope is set to 5 volts per division, but the Fluke is only reading 45.58mV RMS.  It must be at its limit.  Also bonus Tektronix 2230 display.





I also just noticed that for many of the above voltage and resistance numbers I had the Fluke in auto ranging mode.  Forgive me, it got a bit finnicky taking these measurements.
J-R:
I think all of those numbers look good.  You could further explore the minor disagreements by doing some additional cross-checking of different values and ranges (and the slow mode of the Fluke 45).  Use Ohm's law for further calculated verifications.  Although odds are that the Fluke 45 is right and the Hioki is slightly off.  But as mentioned before, if such things are bothering you then you're headed for some kind of higher-end bench DMM with frequent calibrations...

The Fluke 45 ACV accuracy is not specified above 100kHz, and frequency measurements are not defined above 1MHz.  So any displayed values above that are for entertainment only!
bdunham7:

--- Quote from: Fried Chicken on April 14, 2024, 03:22:42 am ---Here it's measuring at "5 volts":

Hioki: 5.174v
Fluke: 5.163v

--- End quote ---

So calibrating the Fluke 45 has only reduced your ~20mV discrepancy to 11mV--but at least you know which is which.  The tolerances for the Hioki work out to 19 counts, so 11 is OK.  Welcome to the "within specs but not as good as you hoped" zone!
Fried Chicken:

--- Quote from: bdunham7 on April 14, 2024, 07:31:52 pm ---
--- Quote from: Fried Chicken on April 14, 2024, 03:22:42 am ---Here it's measuring at "5 volts":

Hioki: 5.174v
Fluke: 5.163v

--- End quote ---

So calibrating the Fluke 45 has only reduced your ~20mV discrepancy to 11mV--but at least you know which is which.  The tolerances for the Hioki work out to 19 counts, so 11 is OK.  Welcome to the "within specs but not as good as you hoped" zone!

--- End quote ---

This is more than adequate for my needs.  The Hioki has similarly always been more than adequate for my needs.  This is by no means a way to verify the calibration of the Fluke.... that question... and the original inspiration for this whole thread I have no way to test your calibration :P  I gotta trust your work, but I do
Navigation
Message Index
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod