[RASMB] Delay calibration and plot appearance

[John Philo]

Karel,

It sounds like you are having a hardware problem. Normally the instrument
only 'looks' at the counterbalance for delay calibration (cell 8 for your
8-hole rotor). However, if it is having trouble it then tries the cell
opposite the counterbalance (cell 4 in your case), with that choice of cell
4 being independent of what cell(s) you have asked it to scan. Thus the fact
that it is telling you it is scanning cell 4 during delay calibration is an
indication that the normal procedure using the counterbalance has failed.

The first thing to do is to check your counterbalance--possibly some dirt is
blocking the precision masks that are used in delay and radial calibration.

You could also be having trouble if your radial calibration is incorrect,
since it expects to be able to see the holes in the counterbalance when it
is at 5.8 cm. Remember, NEVER tell the instrument to do a radial calibration
at any rotor speed other than 3000 rpm. If you mistakenly did a radial
calibration when the rotor was stretched at high speed then at low speed the
delay calibration would probably fail because at the position it thinks is
5.8 cm it would be looking at metal.

The plotting problem indicates that somehow the template file that contains
the default formatting for that graph has gotten altered. The simplest
solution would probably be to uninstall and re-install the instrument
control software (the "GUI"). The file involved is actually an ORIGIN
template file (.otp); I believe it is called absorbance.otp or something
like that and should be in the folder with the GUI program. It is actually
possible to modify those default graph formats using ORIGIN, but very few
users are aware of this and it is hard to imagine you could have done this
accidentally.

John Philo
Alliance Protein Laboratories

-----Original Message-----
From: rasmb-admin at server1.bbri.org [mailto:rasmb-admin at server1.bbri.org] On
Behalf Of Karel Planken
Sent: Wednesday, November 24, 2004 2:43 AM
To: 'rasmb at rasmb-email.bbri.org'
Subject: [RASMB] Delay calibration and plot appearance


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Dear AUC users,
Does anyone of have detailed information on the delay calibration? Because I
experience that all of a sudden the delay calibration takes quite long to
complete. In addition, rotor hole 4 (eight hole rotor, An-50 Ti) is selected
during this delay calibration prior to an intensity measurement through
rotor hole 1. In contrast, rotor hole 8 is selected during the delay
calibration when I want to measure a sample in hole 4. Does anyone know what
is going on? A complete different problem is, that all of a sudden the plot
lines in the plot that appears when a scan is recorded have a default width
of 1 instead of the much thinner width of 0.2. How can I change the default
width of the lines that are plotted during the measurement (adjusting them
manually is time consuming and inconvenient)?
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