Biosystems MultiPro Reference Manual - ↔
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Once the calibration of all sensors is
successfully completed, the MultiPro will
briefly show the maximum adjustment values
screen.
The maximum adjustment
values for the LEL and
toxic sensors give an
indication of the remaining
sensitivity of the sensors.
As sensitivity decreases,
the maximum possible
adjustment will decrease to approach the
expected concentration of the calibration
gas.
Note: Once the calibration cycle is
completed, the MultiPro will automatically
turn itself off. Disconnect the calibration
assembly prior to turning the instrument
back on.
4.3.1 Span calibration failure: Toxic and
LEL sensors
When there is a span calibration failure, the
display will show CAL Error and display the
sensor whose calibration has failed.
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If the instrument fails to
recognize the correct type
or concentration of
calibration gas, it will
show “no GAS”.
When span calibration is
due, the MultiPro’s
display will show the warning symbol while
intermittently displaying the calibration bottle
in the gas readings screen.
The MultiPro will also display a “Needs Cal”
message for any sensors that are currently
due for calibration during instrument start-up.
Possible causes of span calibration
failure and remedies:
1. Empty calibration gas cylinder. Verify
that there is calibration gas in the
cylinder.
2. Expired calibration gas cylinder. Verify
that the expiration date on the cylinder
has not passed.
3. Calibration gas setting does not
correspond to calibration gas
concentration. The default calibration
gas settings are 50% LEL, 50PPM CO
and 25PPM H
2
S. If the values on the
calibration cylinder are different from
these values, the MultiPro’s calibration
gas settings must be changed to match
the new values. Changing the calibration
gas settings requires the use of the
MultiPro programming software, which is
available separately.
4. LEL only: Type of calibration gas
(standard) has changed significantly.
LEL calibration gas may be based on
several different response standards,
methane, propane and pentane are the
most common. If using a new cylinder of
calibration gas, make sure that the type
and amount of combustible gas is
identical to that of the previous bottle.
Biosystems offers calibration gases in
Methane, Propane Equivalent and
Pentane Equivalent.
5. Dead sensor. Replace sensor.
6. Instrument problem. Return the
instrument to Biosystems. Call the
phone number on the front of this
manual.
4.3.2 Span calibration failure: Oxygen
sensors
Biosystems multi calibration gas cylinders
contains approximately 18.0% oxygen. The
reduced oxygen level in the calibration gas
cylinder allows the
oxygen sensor’s
response to be tested in
the same manner as the
toxic and LEL sensors.
If the O2 sensor fails to
register a reading below 19.5% during the
span calibration, the display will show O2
Too Low followed by the O2 CAL Error
screen immediately after the failed calibration
attempt.
Press MODE to acknowledge the warning
and turn the instrument off.
If the oxygen sensor fails to register the drop
in oxygen during the span calibration while
being challenged with calibration gas
containing less than 19.0% oxygen, it should
be considered out of tolerance and retired
from service immediately.