In a message dated 24/07/2009, paleoartifact@......... writes:

If....it is significantly "self adjusting", it would then seem to be a  
approach that "could" somewhat eliminate that normal temperature problem  and 
open up the use of such similar steel and  simple construction continued test 
use.

Hi there,
 
    I suggest that you fit the end of the boom with a  vertical position 
marker and a vertical ruler and also check the instrument  temperature when 
checking the position. There is NO substitute for direct  measurements! You 
don't see large position variations for periods under about 3  seconds.
 
    The temperature coefficient of Youngs modulus is  2.4 x 10^-4 / C Deg 
for steel. The expansion coeffieicnt is about 12 x 10^-6 / C  Deg 
 
    Regards,
 
    Chris Chapman





In a message dated 24/07/2009, paleoartifact@......... writes:

  
If....it is significantly "self adjusting", it would then seem to=
 be a 
  approach that "could" somewhat eliminate that normal temperature pr=
oblem 
  and open up the use of such similar steel and 
  simple construction continued test use.
Hi there,
 
    I suggest that you fit the end of the boom wi=
th a 
vertical position marker and a vertical ruler and also check the instrumen=
t 
temperature when checking the position. There is NO substitute for direct=
 
measurements! You don't see large position variations for periods under ab=
out 3 
seconds.
 
    The temperature coefficient of Youngs modulus=
 is 
2.4 x 10^-4 / C Deg for steel. The expansion coeffieicnt is about 12 x 10^=
-6 / C 
Deg 
 
    Regards,
 
    Chris Chapman