Kansas kymco, I recently pulled the "China Bombs" off my trailer and installed Goodyear Endurance tires.
I plan to research this tire gauge thing further and ask questions around town.
First attempt in quest for accurate tire gauges:
psi % conversion: examples
65 psi @ 1% = .65 psi
65 psi @ 1.5% = .97 psi
65 psi @ 3% = 1.95 psi
65 psi @ 4% = 2.6 psi
38 psi @ 1.5% = .57 psi
38 psi @ 3% = 1.1 psi
38 psi @ 4% = 1.5 psi
100 psi @ 3% = 3 psi
On some gauges, accuracy can be off even
more than the examples above when reading
on the low and high end of the scale.
ANSI standard
scientific gauges = +/- 0.1% accuracy
grade A gauge = +/- 1% accuracy
grade B gauge = +/- 2% accurcy
grade C gauge = +/- 3% accuracy
grade D gauge = +/- 4% accuracy
Most gauges will be more accurate in
the middle range.
Gauges with large dials tend to read with
more accuracy.
Grade A gauges with a high psi rating are
a little hard to find but, they are out there.
Scientific gauges can be as accurate as 0.1% accurate and they are expensive.
"Master Tire Gauges"
Master tire gauges are manufactured to more
exacting tolerances and as a general rule are
more accurate than other gauges. Usually
classified as Grade A gauges / 1.0% accuracy.
Tire pressure gauges can be calibrated if you
can find a shop or business that has a
"tire pressure gauge calibrator station".
A calibrator station looks like a horizontal
air cylinder with a small pump handle attached.
It will also include a precision large psi dial
on top of it.
Some industrial supply stores sell them.
I think it is the law in California, repair shops and
tire stores have them in their businesses and
are required to check their tire gauges regularly.
In the last few days I stopped at two tire stores
and one Autozone inquiring about "calibrator stations".
They did not know what I was talking about.
My search for new information and a local business
that has a "tire pressure gauge calibrator station
goes on.
Since I posted last, I purchased a new tire gauge. It
is a Vondior 0-100 psi Master Grade A 1% accuracy gauge.
ANSI accuracy through the the full range. Cost $22.60..
I also purchased a Measureman large dial 0.25% accuracy gauge to use as a Master gauge on my "tire gauge calibrator station".
Still would like to find a "tire gauge calibrator station"
in my local area to check and mark all my gauges.
ps: Update, may not need to find a station now that I have my own.
My interest in tire gauge accuracy started because I
ride motorcycles, motor scooters, and pull trailers at interstate speeds.
Will investigate this subject further.
A side note about accurate testing equipment. Calibrator stations can get very expensive. avg. price is around $600.The more I look, the more I find. Also, precision pressure dials can be very expensive.
Names of two tire gauge pressure stations. Dill and Imperial. There
are more to be found. ps: found a Dill for $450. Bet a person can
make one of these. They look simple.
Found a Haltec air checking station for $249.. Don`t know about
the quality of this unit.
More info to come soon for those who are interested.
Link to picture of my homemade " tire pressure regulator station".
https://photos.google.com/photo/AF1QipPU2ui_wZA3P8UpSAlBuVOOMl0y6ZaCAXmDXNuvLink to picture of bourdon tube.
https://photos.google.com/photo/AF1QipNxhdEV62q5zRrpUWtBFZHNzBARVI328J5ee69gLink to picture of Huva cup removal from pen type gauge.
https://photos.google.com/album/AF1QipMURwqC6tTi06LnZ7wJ13ZTfUKLvYo1IJi0IzKU/photo/AF1QipN4S0-f_yfRuVCsN_bK3WygkP73Nf7-UdMnABwJThe Master gauge on my station is certified accurate to 0.25% psi. That is 1/4 of 1 % psi. A Shrader valve is attached to test other gauges against the Master.
Other information: Most dial gauges use a bourdon tube to operate.
Pen type air gauges that can be pulled or screwed apart can be calibrated. Screw the gauge apart, remove the Huva valve and adjust the screw down inside the tube. Test it against a Master gauge or a gauge you have confidence in as being accurate.
I am in the process of testing all my gauges. So far my "air gauge testing station seems to be working good.
I hook my "air gauge calibrator" to my 110 psi air compressor and set the pressure wherever I want. 30psi, 40psi, 50psl, 65psi. and check questionable gauges against my Master gauge.
More important information.
https://photos.google.com/photo/AF1QipPLz7DuaJfO0ra1zdKdGoKW_wi92aJMhPwWnnwo
