So Saturday morning I decide to check my tires - it’s getting colder, so I thought they might have lost a few pounds of pressure. Got out my relatively new digital gauge, and got a reading of 21.5 in the right front. This alarmed me on two fronts; I could not imagine how it got so low, and why the TPMS had not alerted me. I put air in, rechecked and saw only 27.5. Only then did I realize I had inadvertently set my gauge to bars instead of PSI . So what I read as 21.5 was 2.15 bars- at a 14.5 conversion ratio, that’s. 31.2- a little low, but not a dangerous situation. And now I had to let the air out of my 2.75 (39.8) to normal. A combination of my garage not having the best light in the world, my eyes not being what they used to be, and a tire gauge with features I did not know I needed.No harm, lesson learned- could have been worse.
Anybody got similar stories?
Then… I’m not the only one who makes these mistakes??
I can’t think of any specific incident (I can’t even remember what I did yesterday), but I spent a good part of my like juggling metric and American measurements, and I can say with confidence that I’ve probably screwed them up on occasion.
One thing I know I’ve done when using digital instruments is forgotten to “null” the instrument before using it.
At least my mistake was easily rectified. Didn’t NASA lose a Mars lander some time ago because of some English/Metric translation problems/
I keep wondering, though not doing too bad in the pool, are the football odds made in china? was your gauge?
LOL, good point. I don’t remember the details, but I do remember reading something to that effect.
A few months ago, I got kilograms and pounds confused, while recharging an ac system at work
When the relief valve on the compressor popped off, it dawned on me that I probably did something wrong
I worked for many years as a driver for the US arm of a Canadian trucking company. We froze solid two loads of liquid latex because the bill of lading ( Canadian ) said keep at 10 degrees and a US driver set the temp on the reefer to 10 degrees Fahrenheit instead of Celsius ( 50 degrees Fahrenheit ) .
I’ve gotten burned a few times with the alarm clocks that have a goofy red dot to distinguish between AM and PM. Consider that the occasions when you MOST need an alarm for the next day, you’re likely LEAST able to notice a feature as subtle as a freakin’ dot!
I think all alarm clocks should at least have the option for 24 hr time, because of this.
I was checking something a few months ago with a digital VOM and was wondering why I was getting a 20 something volts reading on an automotive electrical system. WTH???
After a recheck and still 20 volts along with some grumbling I noticed the VOM was set for resistance and volts had nothing to do with it… 
I started out on a trip in the early morning hours last week in 18 degree weather. My tire pressures all read 28 psi. I run 32 psi in them all year long and when I checked them with the TPMS while traveling down the interstate about an hour later…they all read 32 psi.
In 1983, an Air Canada flight switched kg and lb and made it half-way across the Canadian plains before running out of fuel at 41,000 ft. There was a “happy” ending with a masterful dead-stick landing on an abandoned runway:
Luckily my cheap tire gauges only read one scale so can’t screw it up. Worth mentioning though that tire pressures are to be checked cold before driving. So if its at 28 and should be 32 but after driving and heating them up it is at 32, they are under-inflated.
And there’s the Mars Climate Orbiter crash:
“On September 8, 1999, Trajectory Correction Maneuver-4 was computed and then executed on September 15, 1999. It was intended to place the spacecraft at an optimal position for an orbital insertion maneuver that would bring the spacecraft around Mars at an altitude of 226 kilometers on September 23, 1999. However, during the week between TCM-4 and the orbital insertion maneuver, the navigation team indicated the altitude may be much lower than intended at 150 to 170 kilometers. Twenty-four hours prior to orbital insertion, calculations placed the orbiter at an altitude of 110 kilometers; 80 kilometers is the minimum altitude that Mars Climate Orbiter was thought to be capable of surviving during this maneuver. Post-failure calculations showed that the spacecraft was on a trajectory that would have taken the orbiter within 57 kilometers of the surface, where the spacecraft likely disintegrated because of atmospheric stresses The primary cause of this discrepancy was that one piece of ground software produced results in a United States customary unit (“English”), while a second system that used those results expected them to be in metric units. Software that calculated the total impulse produced by thruster firings calculated results in pound-seconds. The trajectory calculation used these results to correct the predicted position of the spacecraft for the effects of thruster firings. This software expected its inputs to be in newton-seconds. The discrepancy between calculated and measured position, resulting in the discrepancy between desired and actual orbit insertion altitude, had been noticed earlier by at least two navigators, whose concerns were dismissed.”
Please speak English. Like my boss told me once when I used the term “consumable inventory”. It was slightly over his head. I like color coding myself with red for SAE and blue for metric but I don’t know how you color code software.
Dealing with a Brazilian company years ago regarding our planned design for an ethanol plant, we asked, “Would you like the design drawings in metric units?” They asked, “What units do you usually use?” We said, “English.” They said, “Then use English units. We’ll do the conversions.” Smart company.
@Mayday good thing you didn’t pump it clear up to 32 on the gauge before you noticed the difference.
All units should be clearly defined in the users’s manual. At least this issue happens infrequently, but this is not the only time problems occur.
The units have always been clearly defined in all the user’s manuals I’ve read
insightful I read “Freefall” several years ago and highly recommend it. I recall people returning from Canada complaining about the high cost of gasoline due to total ignorance of imperial gallons (5 quarts) versus US gallons (4 quarts). Following Canada’s metric conversion these same people were probably bragging about the incredibly cheap gas! Mixing and converting different systems of measurement can become a “recipe for disaster”.
Can’t we just please go metric and solve all this stuff? Oh wait, we tried that and rejected it.
All new assemblies at GM we done in metric starting about 1977. The small-block V8, since it was pretty much the same from 1955 to 1985, had English bolts while the rest of the car was metric. Imagine the motor mount bolts into the block were English and the other side to the frame were metric. We all needed 2 sets of wrenches handy at all times. I think the engine finally changed over completely when the LS-1 came out in 2001 or so.