Scott 973 - Wrong Perforation In Catalouge..??

Agreed John..I will tr to post appropriate wording from now on.

Now talking about measurement gauges...I took the ""Ideal Gauge"" and the ""Unitrade Perfect Gauge"" to see the accuracy of the "Ideal Gauge"

below are the gauges I am talking about to show new collectors what I am referring to in gauges.



I took the ideal gauge, and placed it down and overlapped the perfect gauge over top....I centered in on an example which was perforation 14...When the perfect gauge was placed on top, it did not align with the ideal gauges perforation 14..It looked like perf. 14.1 as per the unitrade perfect gauge..DO YOU GUYS AGREE..???

Made in Canada wins out over Made in USA.

Haha lithograving
Hey..No insult to our American friends..Just good humour.

Robert

No insult intended wert.

Just friendly competition.

Robert,

I use an Stanley Gibbons Instanta. Any idea how does it compares to the Unitrade Perfect gauge?

Peter

You know what Peter..That is a good question..Matter a fact how do ALL gauges compare to each other for accuracy..??

I have one some where and another 2 but they are probably buried in my tots..Will try to find them.

Robert

lithograving...No offense taken {I hope}..Just fun.

Robert, there may be some confusion here.
Here is what I meant.

Some time ago, you sent me a digital Perforation guide, which needed
to "layer" digitally over a scan of a 600dpi stamp.
I was using that, then I thought I recalled Don suggesting this may be
inaccurate (for whatever reasons I cannot remember)

I was thinking in this thread you were still using it.
Then Don explained you were using a camera over a guage
A completely different method.

I have no issues with the Unitrade guage.

I was trained with a large Telephone telecommunication company on "Root Cause Analysis".
So there has to be a {minimum } of 100 items for true analysis to take place...Below is what I think would have to happen to gather accurate gauge information....Here are 3 scenarios

Number one – Would need 100 collectors to send me each and every gauge they have. These gauges would sit for 24 hours { as Don says } to acclimatize for assurance of expansion and shrinkage. This way on say a Canada 929 stamp could probably get a 98% accuracy rate.

Number two – To send MY stamp { Scott 929 } to 100 people for them to check for accuracy with their gauges. I am guessing about a 95% accuracy rate.

Number three – To have 100 people pull out their Scott 929 and do accuracy reading in their atmosphere. I suspect about a 90-95% accuracy.

Would be very interesting what the accuracy rate is with all those gauges out there.

BUT...Would never happen

Robert

As there has been some discussion on the accuracy of perforation guages, I thought I should check my Unitrade gauge.

I used a Peak Optical 10x scale loup which can measure to the nearest 0.1mm and tried to measure the distance between 5 lines at the perf 10 gauge (which should be exactly 10mm). I found I couldn't do it as it measured anywhere from 9.9 to 10.1 mm depending on how I looked at it. The problem seems to be that the printed part of the gauge appears to be sandwiched between two hard layers of plastic. The gauge is about 0.7mm thick, so my loupe was actually about 0.3mm above the printed scale and there was significant parallax error.

This isn't a problem if you use the gauge correctly (i.e. look straight down to where you are measuring), but will make a slight difference if you only look from one viewpoint.

I tried doing the same measurement shown by Wert above, and found that if I looked from further away and straight down at each end, both gauges agreed on perf 14. If I looked from nearby (about 3 inches) from a single viewpoint, the Unitrade gauge thought the perf 14 was actually 14.1.

Since cameras photgraph from a single viewpoint, readings may be slightly higher than they should be. Take care in interpreting your results.

Jan

The older versions of the Unitrade Perfect Gauge are not as accurate as the newer versions. Over time, they have managed to make accuracy corrections to their perforation gauge. On the other hand, according to many experts, the Stanley Gibbons Instanta Gauge appears to be the oppsite in which the much older versions are more accurate than the newer versions. It is always important to check the accurancy of a perforation gauge against a separate accurate ruler.