“I concur”!! 
I purchased a set years ago from a certain InterNachi Inspector when he first produced them. I’ve used them on-site once, and they were then deposited into my garage toollbox where they’ve resided ever since.
Very good quality tools, but useless for an Inspector in the field!!
Well, I paid for 3 day shipping on InspectorOutlet on Monday Feb 24, today is Saturday Mar 1 and still they haven’t arrived. Today I found out through USPS tracking that the shipping label was just created yesterday Feb 28th, the day after I should have received them. Now it says they are scheduled to arrive Tuesday Mar 4th at 9pm. 
quick question: where is the printing on this one? i couldn’t find any but it could have faded away over the last 70 years or so.
Printing on the wires is one reliable solution. Others were mentioned. Such as…
Timothy, would you use a wire gauge that measures the sheathing on the wire you have pictured?
i don’t use anything to measure them, that would be invasive. i have a set of examples to look at, copper and aluminum. gets me close enough for an inspection. if i saw that cloth insulation on wiring on an inspection, it would get called out as “Not able to determine proper wire sizing due to age and/or materials”.
@ryoung7 thanx for the reference link. duly noted and saved.
Yep, no printing left or sometimes on this old cable it wasn’t printed. When I see this, I check the breaker size. Usually I can tell by looking at the wire what size it is. Usually in houses that old it is usually 14 ga and it should be on a 15 amp breaker. If it isn’t, and you can’t tell the wire size then measure it.
yeah, no. that would never happen. i’m not an electrician and even if i were, this is a home inspection, not a wire measuring party. if i were not able to visually guess while looking at the breaker or an unexposed section of the wire, i am not sticking anything into the panel to measure it, that would make it invasive. the only samples i don’t have are tinned copper and smaller aluminum.
I don’t think measuring a wire (and I’m not telling you to measure a wire) in a panel is “invasive” at all.
Cutting a hole in a wall to see something that is otherwise not accessible or visible is “invasive”.
i didn’t think pulling back a ceiling tile was invasive until the inspector on my home didn’t do it. i wish he had so we would have found the huge hornets nest under the stairs in the grid ceiling.
you may be correct in that it isn’t invasive, technically, but it isn’t safe under some circumstances. i am not qualified to determine all of those circumstances. i tend to stay away from them on the job. at my own house i do what needs done. my two years of electrical training is 35 years old and things are way different in many areas, but ac still uses 60hz and dc still flows from negative to positive.
@bcawhern1 i think technically exhaustive is a much better term, thanx for that.
Absolutely. If you’re not comfortable doing it then don’t. If it looks questionable just note it in your report to refer it to a licensed electrician.
I was litigated for not opening a ceiling “roof space hatch” no attic, because I do not stand on furniture and there were 9 real estate agents in the room.
Not kidding.
So, they don’t sell ladders in Canada?
Smart ass.
Floor to ceiling book cabinetry.
No safe purchase to mount a ladder.
I could not open the hatch. It would not move with me contorted like a pretzel.
As well, did I mention 9 real estate agents in the room? As well, a provincial mandate stating only 1 agent per inspection at the residence. Right after COVID 19.
That’s not insulation. That’s outer sheathing. The print on woven sheathing is often worn off. With small gauge NM cable, an experienced inspector should be able to determine the gauge by looking at the conductor. Another option would be to use a wire stripper that has a separate notch for each wire gauge.
The important thing for an inspector to understand is that measuring the outside diameter of the insulated conductor is not a reliable way to measure the gauge. Either go by what is printed on the insulation or on the sheath, or measure the actual conductor.
That’s hilarious and sad at the same time.
