From our school correspondent

Our school correspondent, has written in with the following comment on the Andronov Temperature scale. If you want to see the previous articles on the subject they are here: Let me take your temperature on this and Temperature rising.

A little learning is a dangerous thing or so it is said. So as a pedant I would first like to point out that temperatures are measured in degree fahrenheit, degree celsius and kelvin noting that the names are started with a lower case letter to avoid confusion with the surnames of the scientists. Also a redefinition of the triple point of water means that the boiling point of water is no longer 373.15 K!And so to a useful “scale” or rather a more practical conversion between celsius (the unit I use in my capacity as a teacher) and fahrenheit (my preferred unit in relation to the weather). I claim no originality for this rather state what I heard and then make a further observation. Instead of playing around with ±32 and 5/9 or 9/5 a reasonably accurate, and hence perfectly acceptable, formula is “take thirty from the fahrenheit temperature and divide the answer by two” as shown in the table below:

t / °C

t / °F

t / °

error

-20

-4.0

-17.0

-3.0

-18

-0.4

-15.2

-2.8

-16

3.2

-13.4

-2.6

-14

6.8

-11.6

-2.4

-12

10.4

-9.8

-2.2

-10

14.0

-8.0

-2.0

-8

17.6

-6.2

-1.8

-6

21.2

-4.4

-1.6

-4

24.8

-2.6

-1.4

-2

28.4

-0.8

-1.2

0

32.0

1.0

-1.0

2

35.6

2.8

-0.8

4

39.2

4.6

-0.6

6

42.8

6.4

-0.4

8

46.4

8.2

-0.2

10

50.0

10.0

0.0

12

53.6

11.8

0.2

14

57.2

13.6

0.4

16

60.8

15.4

0.6

18

64.4

17.2

0.8

20

68.0

19.0

1.0

22

71.6

20.8

1.2

24

75.2

22.6

1.4

26

78.8

24.4

1.6

28

82.4

26.2

1.8

30

86.0

28.0

2.0

32

89.6

29.8

2.2

34

93.2

31.6

2.4

36

96.8

33.4

2.6

38

100.4

35.2

2.8

Perfectly adequate (±1° most of the time) for those of us who live in England. Our friends in hotter or cooler climates might consider whether a tweak to the constant “thirty” is worth it.

6 thoughts on “From our school correspondent

  1. Igor says:

    Well I have to say that it has only taken our school correspondent about two years to respond to the post… So our little and slightly inaccurate learning has served us well up to this time. Just like the approximate conversion to and from Celsius and Fahrenheit has been serving well for some time. What is surprising is that a pedant would accept this approximation, surely he should insist on the accurate calculation to be performed each time.

  2. Alex Andronov says:

    I would like the school correspondent to let us know what the true kelvin value for 227.3A is if 373.15 is wrong.

  3. kris says:

    Thing is, why does it matter anyway? Why should I care what the temperature is?

  4. Alex Andronov says:

    Well that’s a good point Kris.But that’s why the Andronov scale is so useful. It only concerns itself with the key important bits of information. Who cares what temperature water boils? We know when it’s boiling because of the bubbles.But the key things you need to know are: Will I need to de-ice the car (freezing is at 0). What temperature should I set the thermostat to (comfortable is 50). Should I pack my shorts (hot is 100).And I think that’s all you need to know.

  5. kris says:

    You set the thermostat to “comfortable”. You de-ice the car when there’s ice on it. And you never wear shorts.All without the need for numbers.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: