Loading ...
Sorry, an error occurred while loading the content.

Re: Quick Q about Thermometers

Expand Messages
  • slacker75@hotmail.com
    ... Just had a thought... (I know, I know, I m replying to my own posts again...!) But I live at about 250m above sea level. I assume I d need to take the
    Message 1 of 5 , Oct 2, 2001
    • 0 Attachment
      >one reads 99C, the other 96C.

      Just had a thought... (I know, I know, I'm replying to my own posts
      again...!) But I live at about 250m above sea level. I assume I'd
      need to take the lower boiling point of water into account when I
      test the thermometers accuracy? How much lower will the BP of water
      be?

      Thanks
      -Tone
    • Ackland, Tony (CALNZAS)
      Tone - I doubt that its the cause, but a better factor rather than altitude is the barometric pressure at the time.. http://biggreenegg.com/boilingPoint.htm
      Message 2 of 5 , Oct 2, 2001
      • 0 Attachment
        Tone - I doubt that its the cause, but a better factor rather than altitude
        is the barometric pressure at the time..

        http://biggreenegg.com/boilingPoint.htm


        Tony
      • Dick
        In message , slacker75@hotmail.com writes ... I ve just had a similar problem, the old faithfull thermometer (country of origin
        Message 3 of 5 , Oct 3, 2001
        • 0 Attachment
          In message <9pdfvl+djik@...>, slacker75@... writes
          > Hi,
          >   Just wondering... I have 2 12" long thermometers, and they both
          > read temps. within about a degree of each other for most of the
          > range, but when i put the bulbs in boiling water, one reads 99C, the
          > other 96C.  I would have expected them to be a 1 degree or so out,
          > but 96C?  Does it matter how much of the thermometer is exposed to
          > the air?  I know its the CONSISTENCY that matters, but this test
          > would seem to suggest that ONE of them ISN'T consistant. 
          > (Incedentally, the one that read 96C was more expensive than the one
          > that reads 99C!)
          >
          I've just had a similar problem, the 'old faithfull' thermometer (country
          of origin unknown, accuracy unknown !) readings were up to 4-5 deg
          different from the digital thermometer (battery flat ?). Solution - go out to the
          local lab equipment supplier and buy a thermometer of known provenance,
          in my case BS1704 (British Standard), known UK manufacturer & marked
          accuracy - brand new & unused cost me £2 from his obsolete stock shelf. If
          you suspect a thermometer I suggest changing it for one with at least some
          form of national standard mark on it, all lab standard thermometers I looked
          at were also marked up with a range, accuracy and required immersion (e.g.
          G.P.105C/1.0/Total).

          For absolute accuracy the amount you immerse a thermometer in
          hot liquid/vapour can also effect the reading (I'm not sure by how much & if
          this applies to all types of thermometer) - some thermometers have a line
          marked round them to indicate how far you push them in.

          If still not happy then you can buy thermometers with a calibration
          chart - but it'll cost you !!!!!! Hope the info is of some use.
          --
          Dick
          Fra' Auld Reekie
        • slacker75@hotmail.com
          Dick, ... The one that read 96C (Made in France) says Total Immersion , whereas the other (made in England) just says Immersion . I m currently testing my
          Message 4 of 5 , Oct 4, 2001
          • 0 Attachment
            Dick,

            > For absolute accuracy the amount you immerse a thermometer in
            > hot liquid/vapour can also effect the reading (I'm not sure by how
            > much & if this applies to all types of thermometer) - some
            > thermometers have a line marked round them to indicate how far you
            > push them in.

            The one that read 96C (Made in France) says 'Total Immersion',
            whereas the other (made in England) just says 'Immersion'. I'm
            currently testing my still, so if I find these two to be a problem,
            I'll take a leaf from your book and get a 'proper' one!

            -Tone
          Your message has been successfully submitted and would be delivered to recipients shortly.