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Hi, The picture on your electronics stack exchange post shows that you are using a solderless breadboard. This is very likely contributing significantly to your "phantom" resistance. I count at least 6 breadboard connections in the picture any one of which could contribute several ohms if you are unlucky!
The contacts in these things are only spring loaded so any oxidisation on the contacts or the wires will contribute additional series resistance.
Make sure that all the wire ends, including the resistor are freshly cleaned and I would also try to remove some of the oxidation from the breadboard contacts by inserting and removing each wire several times.
Better still, take the breadboard out completely and solder the battery and one end of the resistor directly together. Even then you will still have spring loaded connections from the crocodile clips on the ends of the meter leads.
I understand that you are trying to produce something that is reproducible by people without an electronics workshop, but for you tests I would also try to eliminate the battery by using a bench power supply so you can eliminate voltage droop.
Graham
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Excellent advice!
I hate breadboard - but nowhere near as much as I hate wirewrap ... 
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
AntiTwitter: @DalekDave is now a follower!
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OriginalGriff wrote: but nowhere near as much as I hate wirewrap
Just when I hoped you would wrap up my new boards for me...
I have lived with several Zen masters - all of them were cats.
His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.
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Oh I do it from time to time - but I don't like it. The amount of time you spend chasing bad contacts because you wiggled it slightly... 
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
AntiTwitter: @DalekDave is now a follower!
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Great info and I really appreciate it. Thanks very much.
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You can't monitor a system without affecting its behavior. 
I'm glad I don't do electronics (my father did).
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PIEBALDconsult wrote: You can't monitor a system without affecting its behavior.
So true.
Luke (PiebadConsult), come to the dark side.
Electronics and open h/w is so amazing now. So much fun. You must get started.
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One other suggestion: I'd be careful putting any multimeter in series to measure current. It's very easy to blow your meter. Yes, I know they have fuses, never the less, caution. Years ago I worked with a seriously overpowered EE. This guy was chasing a "spurious" signal in his control circuit. In attempts to isolate things, he had done all sorts of things to the scope probes, no ground wires, etc.
When he noticed the insulation dripping off the probe wires, it was too late.
At this point, I think he said something like "elephant it" and added a resistor.
Charlie Gilley
<italic>Stuck in a dysfunctional matrix from which I must escape...
"Where liberty dwells, there is my country." B. Franklin, 1783
“They who can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.” BF, 1759
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The movie "Black Panther" had two white actors: Andy Serkis and Martin Freeman, who also played Gollum and Bilbo Baggins in "The Hobbit" trilogy.
Does that make them the Tolkien white guys? Hmmmmm ....
Sorry - I'll get me coat.
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
AntiTwitter: @DalekDave is now a follower!
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you, just filling in the small parts
Signature ready for installation. Please Reboot now.
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Yes, he played Bilbo, it's written all over him 
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Griff, if you are going to post stuff like this, PLEASE include a "you might want to swallow your coffee first"....
Charlie Gilley
<italic>Stuck in a dysfunctional matrix from which I must escape...
"Where liberty dwells, there is my country." B. Franklin, 1783
“They who can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.” BF, 1759
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RIP
If you have an important point to make, don't try to be subtle or clever. Use a pile driver. Hit the point once. Then come back and hit it again. Then hit it a third time - a tremendous whack.
--Winston Churchill
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Hey man, I never failed a drugs test too.
Kudos to him. ![Rose | [Rose]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/rose.gif)
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After watching Bannister break the 4 minute barrier (B&W 8 inch 405 line TV), I decided I had to run a mile.
Fortunately, I lived alongside a section of the A13 that had 'Lay-by Half a Mile Ahead' road signs.
So, I ran along the footpath from the nearside sign to the opposite side sign.
Strange kid.
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Is a fail positive or negative?
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Yes, rather confusing to "not fail a drugs test". So he passed the drugs test?
Let me confuse it more; we know from pregnancy-tests that a reaction (positive) means you're fooked, and a non-reaction (negative) equals freedom. That must mean that if you "pass" a alcohol or drug-test by getting a reaction (positive) and a fail if you don't get a reaction (negative).
Bastard Programmer from Hell 
If you can't read my code, try converting it here[^]
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The 'positive' is always what you are testing for. A drugs test is testing for drugs, therefore finding them would be a 'positive' result.
It will, however, have a negative result on one's sports career. 
Ad astra - both ways!
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So, if you not fail a drugs test, you took drugs?
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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He was a wonderful and extremely modest man who was always far prouder of his achievements in neurology than his historic sporting moment.
Amazing to think that he could achieve what he achieved essentially as a hobbyist - do the day job, jump on a train, pull off the "impossible" just for fun. That's kind of impressive!
98.4% of statistics are made up on the spot.
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So I wanted to combine two select expressions in EF Core 2.0.
Something like context.MyTable.Select(e => new TModel { ... }).Select(additionalSelector).ToList();
Now that's just not possible, because the first Select converts the query to IQueryable<TModel> and the second Select has no reference to the entity (unless I put it in the model, not sure if that works, but I don't want to anyway).
So I found myself "merging" two select expressions which went awry because the "e" in additionalSelector isn't the same "e" as in the original selector [read: reference to ParameterExpression].
And Expressions are immutable... 
So I wanted to start by converting the entire tree manually (and probably drop the idea because that isn't worth it) when I found the ExpressionVisitor[^].
All that manual work pretty much became:
public class ExpressionParameterSwitcher : ExpressionVisitor
{
private readonly ParameterExpression parameter;
public ExpressionParameterSwitcher(ParameterExpression parameter)
{
this.parameter = parameter;
}
protected override Expression VisitParameter(ParameterExpression node)
{
return parameter;
}
}
Good times 
Thought I'd post it here in case anyone ever needs it and, like me, didn't know about the ExpressionVisitor.
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How did you ever find that? And how did you figure out how it works from the incredibly sparse MSDN documentation? I found what looks like a decent tutorial, of course not by MS, which I'll have to read through now.
Latest Article - Contextual Data Explorer
Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny
Artificial intelligence is the only remedy for natural stupidity. - CDP1802
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