DH Instruments COMPASS FOR MOLBOX, User Manual

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COMPASS

for molbox™ User’s Manual
© 1998-2003 DH Instruments, Inc .
Page 24
Figure 11. Example 5, System Configuration
5.1.5.4 RUN THE TEST
Use [Run] , [Run Test] to start a test sequence (see Section 7.2).
5.1.6 EXAMPLE #6
“How do I set up to test at a single flow point for an extended period of time?”
You may desire to use COMPASS and the molbox/molbloc to capture mass flow data at one flow
point over an extended period of time. This test method could be useful, for instance, to determine
the stability of a DUT over time at a single set point.
5.1.6.1 DUT DEFINITION SETUP
Select or create a DUT Definition that matches the characteristics of the DUT
that you will be running (see Section 8).
5.1.6.2 TEST DEFINITION SETUP
Select the [Setup], [Test], [Points] table, and enter the test point at which you
would like to acquire the data (see Section 9).
Select the [Setup], [Test], [Sequence] tab, and enter the test sequence
parameters. In order to run a long-term test, you can enter up to 100 readings
per flow point. During the test, complete point reading sequences including
averaging time will be made one after another with only the calculations, data
storage, and data plotting operations in between. To make even more readings,
repeat the same point in the
<Points> table.
If your DUT is a controller, or you are using an “other controller”, COMPASS
has an option for two modes of flow regulation. You can select for
COMPASS to make periodic flow control updates, and you can close the control
loop on either the reference flow, or the DUT output (see Section 9.5.6).