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Re: [tec-scopes] Re: TEC110FL temperature stability , negative temperature correction

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  • Bruce MacEvoy
    kelvins are also stated without degrees . (the sun is about 6000 kelvins, not 6000º kelvin.) the standard abbreviation for micron (micrometer)
    Message 1 of 16 , Aug 23, 2013
      kelvins are also stated without "degrees". (the sun is about 6000 kelvins, not 6000º kelvin.)

      the standard abbreviation for micron (micrometer) is μm, greek μ (for millionth) and m (for meter), but it's awkward to find the right keystroke to make the mu and its appearance in this html email may be garbled on some computer displays.

      picky, picky, picky.

      bruce


      From: Guilherme de Almeida <guilhermedealmeida@...>
      To: tec-scopes@yahoogroups.com
      Sent: Thursday, August 22, 2013 9:26 AM
      Subject: Re: [tec-scopes] Re: TEC110FL temperature stability , negative temperature correction

       
      Hi,
       
      According to the international standars for symbols and names for units and magnitudes, the correct form is
      to write Kelvin for the man and kelvin for the unit (named after Lord Kelvin's name).
       
       
      Regards
      Guilherme de Almeida
       
       
       
       
      ----- Original Message -----
      From: Yuri
      Sent: Thursday, August 22, 2013 5:18 PM
      Subject: [tec-scopes] Re: TEC110FL temperature stability , negative temperature correction

       
      Gerhard,
      I do not know Mr. Kelvin...
      the unit is micron (in German mikron).
      Regards, Yuri

      --- In tec-scopes@yahoogroups.com, Gerhard Henning <gerhard-henning@...> wrote:
      >
      > Hi Yuri ,
      >
      > Thanks for answering , what is the unit " mK " ?
      > Normally I would think milli-Kelvin.
      >
      > Bert Regards , Gerhard
      >



    • gerhardhenning53
      Hi Yuri , That means -5 microns / °C , is it correct ? ( or 5 °C ??? ? ) Thanks for answering Gerhard --- In tec-scopes@yahoogroups.com, wrote:
      Message 2 of 16 , Aug 30, 2013

        Hi Yuri ,


        That means -5 microns / °C , is it correct ? ( or 5 °C ??? ? )


        Thanks for answering


        Gerhard



        --- In tec-scopes@yahoogroups.com, <tec@...> wrote:

        Gerhard, here is my appr. calculations:
        Going from 20C to 15C we have following happens:
        Al tube shortens ~50mk
        Objectives BFL shortens ~45mk
        To compensate above changes focuser have to move further from objective ~5mk
        Regards, Yuri

        --- In tec-scopes@yahoogroups.com, Gerhard Henning <gerhard-henning@...> wrote:
        >
        > Hi,
        >
        > My question : I have TEC110FL with a moonlite-steppermotor as focuser
        > and the adequate controller.
        >
        > I testet for 10 times the calibration of the temperature-curve. I don?t
        > understand it, but I have in every time a negative correction. for example :
        >
        > at 20 degree I have 10000 motorsteps for correct focus , and for 15
        > degree only 9000 steps. I think it is logical, that it should be opposite.
        >
        > What is the reason why ?
        >
        > Is the expansion coefficient of Calziumfluoride responsable ?
        >
        > Thanks for answering
        >
        > Best regards
        >
        > Gerhard Henning
        >
      • sternwarte-wachtberg
        Hi Yuri , That means -5 microns / °C , is it correct ? ( or 5 °C ??? ? ) Thanks for answering Gerhard
        Message 3 of 16 , Aug 30, 2013
          Hi Yuri ,


          That means -5 microns / °C , is it correct ? ( or 5 °C ??? ? )


          Thanks for answering


          Gerhard
        • yuri80226
          Gerhard, the calculations were done for dT of 5°C. It to be 1micron/°C. Regards, Yuri --- In tec-scopes@yahoogroups.com, wrote:
          Message 4 of 16 , Aug 31, 2013

            Gerhard,

            the calculations were done for dT of 5°C. It to be 1micron/°C.

            Regards, Yuri



            --- In tec-scopes@yahoogroups.com, <sternwarte-wachtberg@...> wrote:

            Hi Yuri ,


            That means -5 microns / °C , is it correct ? ( or 5 °C ??? ? )


            Thanks for answering


            Gerhard
          • yuri80226
            - to be correct the focus shift is negative and is -1micron/°C. Yuri --- In tec-scopes@yahoogroups.com, wrote: Gerhard, the
            Message 5 of 16 , Aug 31, 2013
              - to be correct the focus shift is "negative" and is -1micron/°C.
              Yuri

               



              --- In tec-scopes@yahoogroups.com, <tec@...> wrote:

              Gerhard,

              the calculations were done for dT of 5°C. It to be 1micron/°C.

              Regards, Yuri



              --- In tec-scopes@yahoogroups.com, <sternwarte-wachtberg@...> wrote:

              Hi Yuri ,


              That means -5 microns / °C , is it correct ? ( or 5 °C ??? ? )


              Thanks for answering


              Gerhard
            • sternwarte-wachtberg
              Thank´s Yuri , But in many experiments , I measured a value about -100 microns/°C [ mean, +- 20 , n=15 ]. 1 micron is obviously a theoretical value , isn´t
              Message 6 of 16 , Aug 31, 2013
                Thank´s Yuri ,

                But in many experiments , I measured a value about -100 microns/°C [
                mean, +- 20 , n=15 ].
                1 micron is obviously a theoretical value , isn´t it ?
                What is the reason why ?

                Best regards

                Gerhard
              • yuri80226
                Gerhard, is it –100mk /°C ? Also, what is the resolution of your focuser motor? (steps per micron) Yuri --- In tec-scopes@yahoogroups.com,
                Message 7 of 16 , Sep 2, 2013
                  Gerhard,
                  is it –100mk /°C ?
                  Also, what is the resolution of your focuser motor? (steps per micron)
                  Yuri

                   



                  --- In tec-scopes@yahoogroups.com, <tec-scopes@yahoogroups.com> wrote:

                  Thank´s Yuri ,

                  But in many experiments , I measured a value about -100 microns/°C [
                  mean, +- 20 , n=15 ].
                  1 micron is obviously a theoretical value , isn´t it ?
                  What is the reason why ?

                  Best regards

                  Gerhard
                • sternwarte-wachtberg
                  Hi Yuri , I have 200 steps for 100 microns. Gerhard ... Hi Yuri , I have 200 steps for 100 microns. Gerhard Am 02.09.2013 17:11, schrieb
                  Message 8 of 16 , Sep 2, 2013
                    Hi Yuri ,

                    I have 200 steps for 100 microns.

                    Gerhard


                    Am 02.09.2013 17:11, schrieb tec@...:
                     
                    Gerhard,
                    is it –100mk /°C ?
                    Also, what is the resolution of your focuser motor? (steps per micron)
                    Yuri

                     



                    --- In tec-scopes@yahoogroups.com, <tec-scopes@yahoogroups.com> wrote:

                    Thank´s Yuri ,

                    But in many experiments , I measured a value about -100 microns/°C [
                    mean, +- 20 , n=15 ].
                    1 micron is obviously a theoretical value , isn´t it ?
                    What is the reason why ?

                    Best regards

                    Gerhard

                  • yuri80226
                    Gerhard, the permitted defocusing range for F5.6 is ~30mk. Changing T for 2-5 degrees should not ask for re-focusing. And if your electrical focuser do
                    Message 9 of 16 , Sep 4, 2013
                      Gerhard, the permitted defocusing range for F5.6 is ~30mk.
                      Changing T for 2-5 degrees should not ask for re-focusing.
                      And if your electrical focuser do refocusing all the time - it probably lives his own independed life.
                      I will do the test of similar scope in a week and will post here the result.
                      Regards, Yuri

                       



                      --- In tec-scopes@yahoogroups.com, <tec-scopes@yahoogroups.com> wrote:

                      Hi Yuri ,

                      I have 200 steps for 100 microns.

                      Gerhard


                      Am 02.09.2013 17:11, schrieb tec@...:
                       
                      Gerhard,
                      is it –100mk /°C ?
                      Also, what is the resolution of your focuser motor? (steps per micron)
                      Yuri

                       



                      --- In tec-scopes@yahoogroups.com, <tec-scopes@yahoogroups.com> wrote:

                      Thank´s Yuri ,

                      But in many experiments , I measured a value about -100 microns/°C [
                      mean, +- 20 , n=15 ].
                      1 micron is obviously a theoretical value , isn´t it ?
                      What is the reason why ?

                      Best regards

                      Gerhard

                    • sternwarte-wachtberg
                      Yuri , thank´s a lot, Gerhard ... Yuri , thank´s a lot, Gerhard Am 04.09.2013 18:45, schrieb tec@telescopengineering.com :   Gerhard, the permitted
                      Message 10 of 16 , Sep 4, 2013
                        Yuri , thank´s a lot,

                        Gerhard


                        Am 04.09.2013 18:45, schrieb tec@...:
                         

                        Gerhard, the permitted defocusing range for F5.6 is ~30mk.
                        Changing T for 2-5 degrees should not ask for re-focusing.
                        And if your electrical focuser do refocusing all the time - it probably lives his own independed life.
                        I will do the test of similar scope in a week and will post here the result.
                        Regards, Yuri

                         



                        --- In tec-scopes@yahoogroups.com, <tec-scopes@yahoogroups.com> wrote:

                        Hi Yuri ,

                        I have 200 steps for 100 microns.

                        Gerhard


                        Am 02.09.2013 17:11, schrieb tec@...:
                         
                        Gerhard,
                        is it –100mk /°C ?
                        Also, what is the resolution of your focuser motor? (steps per micron)
                        Yuri

                         



                        --- In tec-scopes@yahoogroups.com, <tec-scopes@yahoogroups.com> wrote:

                        Thank´s Yuri ,

                        But in many experiments , I measured a value about -100 microns/°C [
                        mean, +- 20 , n=15 ].
                        1 micron is obviously a theoretical value , isn´t it ?
                        What is the reason why ?

                        Best regards

                        Gerhard


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