Am 22.11.2012 22:04, schrieb David Nečas (Yeti): > It took some time... Anyway, here is a Created DAT file and its ASCII > export (256x256, Z values in Angstroms): > > http://gwyddion.net/download/test/A110813.211738.dat > http://gwyddion.net/download/test/A110813.211738.asc > > Gwyddion loads this specific file correctly now, but this is only due to > the code > > /* FIXME: */ > if (channelbit & CHANNEL_TOPOGRAPHY) > q = 103.0/30.0 * 1e-4 * Angstrom; > > in createc.c. For some unknown reason, this seems to be the correct > conversion factor for this file. > > Yeti
Hello Yeti, this seems specific for your piezo constant and gain setting in the amplifier. For me calculating the factor using the following formula yields the correct result: q = 20.0/2^DAC_bits * ZPiezoconst * GainZ * Angstrom/DAC_Unit DAC_bits is the part before "bits" in value of the field "DAC-Type" which is always 20 in my files. ZPiezoconst is the value of the field "ZPiezoconst". GainZ is the value of the field "GainZ / GainZ". The factor 20.0 is the voltage range the electronics can deliver to the amplifier. For the x and y coordinates the converstation factors are corresponding 20.0/2^DAC_bits * XPiezoconst * GainX * Angstrom/DAC_Unit and 20.0/2^DAC_bits * YPiezoconst * GainY * Angstrom/DAC_Unit which are equal to Dacto[A]xy * GainX and Dacto[A]xy * GainY if the x and y piezo constants are the same Martin ------------------------------------------------------------------------------ Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov _______________________________________________ Gwyddion-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/gwyddion-users
