Simple equilibration

Introduction

This section contains an example of how a Watch instruction for simple equilibration can be inserted into a method.

Example instruction

This is an example instruction as it would be presented in the Text pane.

0.00 Block EQUILIBRATE

(Equilibrate)

0.00 Base SameAsMain

0.00 Watch_Cond Less_than, 5 {mS/cm}, CONTINUE

0.00 Hold

0.10 Watch_UV1 Less_than, 100 {mAU}, CONTINUE

0.10 Hold

0.10 End_Block

If you are not using ÄKTA instruments

If you are not using ÄKTA™ instruments, a delay should be added after the Hold/Pause instruction so that the following instruction will not be executed simultaneously with the Hold/Pause instruction.

This is what happens

The table below describes what happens in the above example:

Stage

Description

1

The Watch is started on the conductivity signal and the method is then put on Hold.

2

Continue is issued and Watch_cond is turned off automatically when the Watch_cond condition is fulfilled.

3

Method execution continues issuing a Watch_UV command. Again the method is put on Hold until the Watch condition is fulfilled.

Note: Even though the line

Watch_Cond Less_than, 5 {mS/cm}, Continue

is in the method placed before Hold, the method is put on hold first and then continued only after the conductivity has reached a level less than 5 mS/cm. This is because Hold is an instruction that will be executed at its breakpoint, while Continue is not an instruction but rather an action for the Watch instruction.

Evaluation of the method

This method works satisfactorily although one drawback is that it might never end, and thus consume all of the buffer if the conditions for some reason are unfulfilled. See appendices Equilibration with simple safeguard and Equilibration with extra safeguard.

2005-06-15