350B coolant temp gauge...in the "orange" zone

[breakaway]

After running the dozer for a couple of hours the heat gauge is well into the "orange" side of the temp gauge..and there is a small white hash mark right about where the needle is running...is this the normal running zone? I am working it,but not more than 85% and it is about 80ish out today.I took some readings with an infrared heat gun and the block is 200-205 degrees...the top of the radiator is 185 degrees and it has never boiled over,so I am thinking the center of the "orange" part of the gauge is OK..? When cold,the needle runs in the lower part of the white zone,and works its way up..so it seems to be working...however,when I turn the key off with the gauge reading up in the middle of the "orange" zone,the needle falls to the cold side,like I would expect an electric gauge to do,but when I turn the key right back on,the gauge does not return to the same spot,like I would expect...but maybe it is the nature of the beast? Coolant level is fine,and it has never boiled over.

[MarkW]

About the only accurate way to measure it is how you have done. Gauges, and especially older ones, are never truly on the numbers accurate so the best thing to do is just notice where it runs normally and if it starts running higher than that test the engine temp like you have done.

Of similar interest is that aircraft fuel gauges have only two legal standards of accuracy, they must read "full" when the tank is full, and must read "empty" when the tank is empty but other than that there is no federal requirement for accuracy.

[breakaway]

I ran it for a few more hrs. after lunch,and no issues.Had the infrared temp gun with me and checked the block a few times; never got over 210 degrees,and plenty of fan action,so I won't worry about the gauge.I was just curious how to actually read it as it is an odd unit.
I am amazed how the time seems to fly by when I am playing on the dozer! I only wish it were bigger..I could really make a big mess!