GDS-68XP Operation & Maintenance Manual, Revision 3.5
Page 30
CALIBRATION
PROCEDURE
(INLET
PORT
SAMPLE)
Calibration
using
the
Inlet
Port
will
more
closely
approximate
the
actual
sample
gas
flow
path
through
the
filter,
regulator
and
sequencer
valve.
Connect
the
calibration
gas
cylinder
and
regulator
to
the
input
port,
either
directly
or
via
a
customer
‐
supplied
three
‐
way
valve
such
that
the
input
can
be
connected
to
sample
or
calibration
gas.
CALIBRATION
PROCEDURE
–
INLET
PORT
OBTAIN
THE
FOLLOWING
ITEMS:
1)
CYLINDER
OF
CALIBRATION
GAS
WITH
FIXED
FLOW
REGULATOR
AND
LENGTH
OF
FLEXIBLE
TUBING
2)
CYLINDER
OF
‘ZERO
AIR’
IF
NECESSARY
IF
NOT
PREVIOUSLY
DONE:
1)
VERIFY
THAT
THE
CHANNEL
1
CAL
SPAN
VALUE
MATCHES
THE
CALIBRATION
GAS
TO
BE
USED
2)
VERIFY
THAT
THE
CALIBRATION
GAS
IS
NOT
EXPIRED
ENTER
CAL
MODE:
WAIT
UNTIL
THE
SEQUENCER
IS
IN
PURGE/HOLD
MODE
AS
INDICATED
BY
“L2”
(GREEN)
FLASH
PRESS
THE
“CAL”
KEY
FOLLOWED
BY
THE
“EDIT”
KEY
ATTEMPTING
TO
CALIBRATE
THE
GASMAX
DURING
A
SAMPLE
SEQUENCE
WILL
RESULT
IN
A
CALIBRATION
ERROR
THE
“APPLY
ZERO
GAS”
SCREEN
WILL
APPEAR;
L2
WILL
CHANGE
TO
SINGLE
FLASH
PURGE
AIR
PUMP
WILL
TURN
ON
AND
AMBIENT
(“ZERO”)
AIR
WILL
FLOW
INTO
THE
SENSOR
FLOW
CELL
SET
THE
ZERO
VALUE:
ALLOW
THE
READING
TO
STABILIZE
AND
PRESS
THE
“EDIT”
KEY
TO
ACCEPT
THE
CURRENT
READING
AS
‘ZERO’
IF
THERE
IS
A
POSSIBILITY
THAT
TARGET
GAS
MAY
BE
PRESENT
IN
AMBIENT
AIR,
USE
A
CYLINDER
OF
ZERO
AIR
IN
PLACE
OF
PURGE
AIR
IF
ZERO
READING
IS
WITHIN
LIMITS,
THE
ZERO
CAL
SUCCESS
SCREEN
WILL
MOMENTARILY
APPEAR
THE
“APPLY
SPAN
GAS”
SCREEN
WILL
APPEAR
SET
THE
SPAN
VALUE:
CONNECT
THE
SPAN
GAS
AS
SHOWN
ABOVE
AND
TURN
ON
THE
REGULATOR.
PRESS
“BYPASS”
ON
THE
SEQUENCER
AND
VERIFY
FLOW
ON
THE
FLOW
METER.
ALLOW
THE
READING
TO
STABILIZE
AND
PRESS
THE
“EDIT”
KEY
TO
ACCEPT
THE
CURRENT
READING
AS
‘SPAN’
PRESSING
“BYPASS”
ALLOWS
CAL
GAS
TO
FLOW
THROUGH
THE
SEQUENCER.
ALLOW
THE
GAS
TO
FLOW
FOR
ABOUT
AS
LONG
AS
IT
DOES
DURING
A
NORMAL
SEQUENCE,
USUALLY
BETWEEN
THREE
AND
FOUR
MINUTES.
IF
SPAN
READING
IS
WITHIN
LIMITS,
THE
SPAN
CAL
SUCCESS
SCREEN
WILL
MOMENTARILY
APPEAR
THE
GASMAX
DUAL
SCREEN
WILL
REAPPEAR
SHOWING
CHANNEL
1
IN
PURPLE
(CAL
DELAY)
COMPLETE
CALIBRATION:
PRESS
“RUN”
ON
THE
SEQUENCER
AND
DISCONNECT
THE
SPAN
GAS
CYLINDER
ONCE
CAL
PURGE
DELAY
IS
COMPLETE,
THE
SEQUENCER
WILL
RETURN
TO
THE
PURGE/HOLD
MODE
Figure 7-2: Calibration Procedure (Inlet Port)