Metrohm 766 IC Sample Processor User Manual

Page 82

4.5 Sample racks

766 IC Sample Processor

The rack Type serves for the assignment to a position table internal to

the instrument, in which the positions of the sample tubes in the rack

are defined in tenths of a degree (0-3599) of the full turning angle. The

rack type is coded as

Mxxx-y

, whereby

stands for Metrohm-defined

types. The placeholder

xxx

stands for the number of sample tubes in a

rack. The numerical code

is a special code for the number of rows on

a rack (0 = single-row, 1 = double-row, 2 = triple-row). Position tables

for user-defined rack types can be created with a suitable PC software

and introduced into the instrument via the serial interface. The name of

the rack type may be chosen at will this way.

The Work position determines the height of the needle in which the

sample solution is aspirated. In this way the ideal position for every

sample rack can be chosen dependent on the height of the sample

tubes. This work position can be accessed directly in manual operation

with the key. In a process sequence this can be programmed

with

'LIFT :1 : work mm'

The Rinse position determines the correct position of the needle in

which, for example, a rinsing solution should be aspirated. In this way

the ideal position for every sample rack can be chosen dependent on

the height of the sample tubes. This rinse position can be accessed

with

'LIFT :1: rinse mm'

The Shift position determines the correct position of the needle, in

which the rack can be turned. This height must be 0 mm for the 766 IC

Sample Processor 766. If the lift is not at or above the shift position, the

sample rack can not be turned in manual operation. This is a safety

feature to prevent damage to the needle due to turning maneuvers of

the rack. However, a prerequisite is that this shift position is correctly

set. In a process sequence the positioning of the lift to the shift position

can be programmed with

'LIFT :1 : shift mm'

The Special position determines an additional user defined height of

the needle. This special position can be accessed with

'LIFT :1 : special mm'