Carbon Monoxide Alarm User Manual

Page 21
the cylinder. Turn the regulator off after it has been
screwed into place in the cylinder.
Note: Biosystems recommends the use of a special
corrosion resistant regulator (part number 12-025) for
ammonia and hydrogen chloride calibrations.
Biosystems’ standard regulator (part number 12-023)
may be used for other corrosive gases.
(2) Connect the Teflon

adaptor and length of FEP lined
tubing to the cylinder of calibration gas.
(3) Note the position in which the corrosive gas sensor
has been installed (either Toxic 1 or Toxic 2).
Note: It may be necessary to remove the sensor
compartment cover to verify sensor placement. If
two toxic sensors have been installed the meter
display will list the sensor installed in Toxic 1 first.
TOX
2
TOX
1
L.E.L.
O2
Figure 3.4.1: Placement of PhD
2
sensors in the
sensor compartment
(4) Hold the adaptor directly over the location of the
correct sensor.
(5) Open the calibration gas regulator valve to obtain a
flow of approximately 1.0 liters per minute.
(6) Wait for the readings to stabilize. (In the case of
some corrosive gases stabilization may require three
to four minutes.)
(7) Note the final response.
Readings which are more than 10 percent higher or
any amount lower than expected indicate the
instrument must be “span” adjusted before further
use.
3.4.1.2 Corrosive gas sensor span adjust
procedures
Note: Removal of the sensor compartment cover aids
accurate placement of the calibration adaptor. For
maximum accuracy it is best to remove the sensor
compartment cover before corrosive gas sensor span
adjustment.
(1) Remove sensor compartment cover.
(2) Enter the Span Calibration mode as discussed in
Section 3.4. above.
(3) Connect the regulator, adaptor and length of FEP
lined tubing to the cylinder of calibration gas.
(4) Hold the adaptor directly over the correct toxic
sensor.
(5) Open the calibration gas regulator valve to obtain a
flow of approximately 1.0 liters per minute.
(6) Wait for the readings to stabilize. (In the case of
some corrosive gases stabilization may require three
to four minutes.
(7) When the readings stabilize use the “+” and “−” keys
to raise or lower the readings to match the
concentration printed on the calibration cylinder
label.
(8) When the span calibration has been completed for all
channels, press and hold the “Cal” button until an
information screen indicates that calibration is
complete.