Biosystems EX CHEK Reference Manual - page 22
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message “ZERO WAIT” while the
adjustment is being made.
Z E R O
↑↓
W A I T
(8) To cancel, press the MODE button. This
causes the calibration values in the
memory to remain unchanged from the
last time a fresh air adjustment was
made. An information screen is
displayed briefly which verifies that the
zero values have not been changed.
The instrument will then return to normal
operation.
N O
↑↓
S A V E
(9) After completion of the zero adjustment
the Ex Chek automatically returns to the
gas readings screen.
0
3.5.2 Span calibration using keypad
buttons
Span calibration procedures using buttons
on the instrument keypad are only
necessary when the adjustment necessary
to restore accuracy is outside the
permissible window of adjustment for “One
Button Auto Calibration” procedures. Span
calibration using the keypad buttons may
only be done while in the Technician
operating mode.
(1) Turn the instrument on.
(2) Remove the belt clip by sliding it free
from the belt clip mounts to expose the
four mini-push-buttons.
(3) Verify that the instrument is in the
Technician operating mode. Switch
modes (if necessary) by simultaneously
holding down the "+" and"-" keys.
(4) Each time that the operating mode is
changed, the LCD screen will briefly
indicate the current operating mode.
(5) Turn the instrument off by pressing the
MODE button for three full seconds.
(6) With the unit turned off, press and hold
down the "Cal" button.
(7) While holding down the "Cal" button,
press the MODE button to turn the Ex
Chek back on. A screen showing the
message “SPAN” will be displayed which
alternates with the sensor readings.
S P A N
↑↓
0
Press the MODE button at any time to
cancel the calibration mode.
(7) Attach the cylinder of gas, regulator,
short section of tubing and calibration
adapter to the Ex Chek.
Make sure the
regulator, cylinder seating surfaces and
threads are clean and dry before
attaching the regulator to the cylinder of
gas. Introduction of contaminants
through the regulator fittings may alter or
degrade the concentration of the gas
contained in the cylinder and may lead to
inaccurate and potentially dangerous gas
readings.
(8) The regulator will automatically begin
flowing gas at the correct flow rate as
soon as it is fully inserted. When the
readings stabilize, use the "+" and "-"
keys to raise or lower the readings to
match the concentration printed on the
calibration cylinder label.
Always check the
expiration date on calibration gas
cylinder(s) prior to use. Expired
calibration gas can lead to inaccurate
and potentially dangerous readings.