Metrohm 788 IC Filtration Sample Processor User Manual

Page 103

4.5 Sample racks

788 IC Filtration Sample Processor

The

Code is used for automatic rack recognition. Make sure that this 6-

place binary code in the rack configuration agrees with the actual in-

serted magnet code on the rack. Rack codes can be changed at any

time. They must however, only be assigned to one rack. The assign-

ment of standard predefined codes of standard racks provided by

Metrohm should be avoided. There is one code which can be used for

this purpose. It is normally used for special racks: 110000.

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 788 IC

Filtration Sample Processor. If the lift is not at or above the shift posi-

tion, the sample rack can not be turned in manual operation. This is a

safety feature to prevent damage to the needle due to turning maneu-

vers of the rack. However, a prerequisite is that this shift position is cor-

rectly 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'