I was out riding today and my X has the automatic HVAC on the front there is a button for F/C Fahrenheit and Celsius. The temp on the F setting was 19 degrees and on the C setting -8 degrees. Now if the temp is 32 degrees F the Celsius is 0 degrees correct? The temp went down to 18 degrees F but the C setting was still -8. Can someone please explain the scale of Celsius. I'm actually too lazy to look all this up on the net.

When I got home I turn off the radio, heat and the engine. I opened the door and the highbean on light appeared. I sat and pondered this for a few moments. I restarted the car and all the dash lights came on and the highbeam indicator light went off. I turned the car off and no highbean indicator light. I am starting to like these little idiosyncrasy of these English cars. As long as they correct themselves.

 

Adam, both scales are based on the freezing point and boiling point of water. Where the difference is that with the celsius scale, the freezing point is 0 and the boiling point is 100. Where the fahrenheit scale is based on the freezing point of water being at 32 and the boiling point at 212 (there is a reason for this, just don't recall the basis for those numbers). To convert between the two, it requires a little bit of math (F = 9/5C + 32 or C = 5/9 (F-32)). It is possible that with the temperature only changing by the 1 degree F, that the C temp will remain the same since a degree C is a larger temperature change than a degree F.

If you need more info on this, let me know.

 

you don't want me to get into the K and R scales either. I have to deal with these periodically to get into the theoretical side of my job and proving the efficiency of steam turbines and the whatnot. That is a load of fun. NOT!!!!!!!

 

Thanks for the explanation, Believe it or not I understand the theory between the two now,

 

Celsius yes, Fahrenheit no.

0F is the freezing point of an arbitrary but specific formula of brine, 100 was human body temp, 212 was calculated to be the boiling point of water using the progression of those two points. The two were chosen for repeatability purposes.

Degrees F is still used in only one non-3rd world country- everybody else uses degrees C.

The reading in the OPs car didn't change as OAT is only indicated in 'whole degrees' in either scale, desired interior temps are settable in half degree increments , at least on S types.

 

For the high beam indicator, there is a button on your key that turns the lights on. If you push this button when you are turning the key off, it will acitvate the lights. (and the dash indicator too) ... they stay on for a preset timer or you can turn them off by pressing the button again.

turning the ignition on again, also will stop the timer, as you did.
dont be so quick to jump on gremlims..... there are very few these days.

 

But the question does arise, which is the actual outside temp. As both F and C seem subjective, as MPH and KPH, which one is the true speed marker?

 

Yes I know of this button and I might have pressed it without knowing. I also have locked my car and unlocked by just reaching into my pocket to get my other keys, as I don't keep any other keys on the car key chain. I was told a long time ago never put anything on a car key chain except the cars keys as the weight of all extra stuff can damage the tumblers inside the ignition switch. Thanks

 

Well, that's a strange post, but I guess the only true speed indicator is furlongs per fortnight. Everything else is pretend.

 

Both are measuring the same thing, just using different units of measure to accomplish. So, to say that one is more accurate or anything like that is not correct. The only "advantage" I can give to KPH is that when converting between different units and trying to get to say meters/sec or something like that, it is a bit easier to do than in the english systems.

All measurement systems have defined ways of establishing what that unit of measure is. For the foot, there is a metal bar that has been replicated a number of times that when measured at a specific temperature, is the defining unit of length. As such, the meter is based on the length of a wave from a specific frequency (I don't recall what it is at the moment). Kinda like time is based on a pre-set number of waves of cesium of a specific isotope occurring. The time this takes is a second. The same can be said of units of weight. The kilogram for example is based off of having a 1000 cubic centimeters of pure water. Once you have standards for time, distance, and weight, all other standards can be derived.

 

leave the science to the engineers and scientists.. sound funny coming from you guys.

 

the speed, and temp sensors give an electronic signal to a computer and then the computer turns the signal to a useable number. Then since people are lazy, they only display single digits which have to be rouned up or down to the accoring result..

Since km are smaller than miles, the accuracy of the displayed number will be closer to the correct speed than the miles display. They both come from the same pulse generator at the wheels.
The opposite for temperature. each degree F is smaller than a degree C. There are 212-32=180 degrees F between freezing and boiling, but only 100 degrees C.

so as the temp sensor gives the information to the computer, the F readout will change more often than when set to C.

Does that make ANY sense? lol

 

Thanks for the physics lesson. I watch when I can Top Gear on the BBC. There is also a Top Gear America on the History Channel which is OK but not as entertaining as the BBC Top Gear.

Anyway, I've noticed when the BBC show quotes a speed of a car they say miles per hour. But everything else seems to be metric, amount of fuel,Pound for money , distance etc. Is this just the choice of the show or do you folks in the UK use MPH?