From experiments on capacities for gliding applications, you can expect the 'response time' of the gas in a 1 L bottle to changes in the wall temperature to be of the order of 1.5 to 2 minutes. The response to external pressure changes will be limited by the mass of the fluid in the column, by it's viscosity which is also strongly temperature dependant and by the forth power of the bore of the tube. I would expect the response rate to be limited to small fractions of a Hertz. For every 1 C Deg change in the bottle temperature, the internal pressure changes by about 3.5 milli Bar. To be able to measure pressure changes of the order of micro Bars, would require temperature tracking of the whole bottle to milli degree level. How stable is your external air temperature? The first thing that you notice when observing microbarograph traces are the large fluctuations in pressure due to wind and air turbulence. In looking for pressure changes, the sluggish response of the manometer will be beneficial here, but what do you actually want to measure? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>