Publicidad
Section 3 Operation
®
Brooks
VDM100 Vapor Delivery Module
3.2.3 Zeroing the VDM100
3.2.3.1 Procedure for Manually Zeroing the VDM100
3-4
Over a period of time the flow sensor in the VDM100 could accumulate a
zero offset. lt is recommended that the VDM100 flow sensor is zeroed if this
occurs to insure accuracy when delivering water vapor. There are three
ways to zero the VDM100:
1. Pressing and holding the "ZERO" momentary switch for 3 seconds
2. Using the GUI to give the VDM100 a zero command
3. Turn on the Auto-zero feature available in the VDM100 by using the GUI
to activate it
The following sections explain the manual zeroíng procedure and how the
Auto-zero feature functions.
As mentioned earlier, the VDM100 can be zeroed in one of three ways. Two
of the three ways are performed manually by either pressing the ZERO
switch or issuing a command from the GUI; see Section 4.0 Operation of
the Brooks Graphical User lnterface (GUl) for VDM100 to learn how to issue
the zero command. The manual procedure for zeroing the VDM100 with the
switch or with the GUI is as follows:
1. The VDM100 must be in Normal mode and in its "Ready-to-Use"
condition (green "READY" LED on and amber "WARMUP" LED blinking).
Pin 13 of the DB-15 will be pulled to ground.
2. The VDM100 must not have any fault conditions. The red 'FAULT" LED
must be off and Pins 4 and 10 on the DB-15 must be in their inactive states.
3. There should have been no set point (<1.5% of full scale) given to the
VDM100 for at least 90 seconds.
4. lf the conditions in steps 1 through 3 have been met then take one of the
following steps:
• Press and hold the "ZERO" momentary switch for 3 seconds and release
• lssue the zero command from the GUI (see Section 4.0)
Any non-zero output (flow sensor offset) from the VDM100 - up to a
maximum of 5% of full scale - ("Flow Signal Out", Pin 2, DB-15) should
now be gone.
It is highly recommended that a zero is pertormed when the VDM100
reaches "Ready-to-Use" condition after being put into Normal mode for
the first time.
Installation and Operation Manual
X-VAP-VDM100-eng
Part Number: 541B178AAG
December, 2012
Publicidad
