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3.6.1.2 Forced fresh air/zero calibration
If a fresh air/zero calibration fails in an
atmosphere known to be fresh, the ToxiPro
can be forced to fresh air calibrate as follows.
1. Follow instructions 1 and 2 in section 3.3
to begin the fresh air/zero calibration
sequence.
2. As soon as the alternating right and left
0’s are shown on the screen, press and
hold the MODE button.
↔
3. The forced fresh air/zero calibration is
complete when the instrument emits three
short beeps and then moves on to the
span calibration procedure.
Performing the forced
fresh air calibration in a contaminated
atmosphere will lead to inaccurate and
potentially dangerous readings.
3.6.2 Span calibration failure
The ToxiPro is designed to recognize two
distinct types of span calibration failures:
failures that occur due to sensor response
outside the sensor’s normal range for
calibration and failures that occur when the
instrument fails to recognize any calibration
gas whatsoever.
3.6.2.1 Sensor out of range (no CAL)
If the instrument recognizes calibration gas,
but the sensor response is not within the
range to calibrate the instrument, span
calibration will fail and the “no” and “CAL”
screens will be alternately displayed.
↔
After displaying “no” and “CAL” three times,
the instrument will return to the current gas
readings screen and the warning symbol and
the calibration bottle icon
will be shown, which
signifies that the
instrument failed the last
attempt to span calibrate.
Note: If the Calibration
Due Lockout is enabled, the ToxiPro will
turn itself off following a failed calibration
attempt.
3.6.2.2 No gas
In the case of a span calibration failure in
which calibration gas is not detected, the “no”
and “GAS” screens will be alternately
displayed as shown below with the calibration
bottle icon highlighted.
↔
When the instrument returns to the current
gas readings screen, the
warning symbol and the
calibration bottle icon will
be shown, which
signifies that the last
attempt to span calibrate
the instrument has failed.
Note: If the Calibration Due Lockout is
enabled, the ToxiPro will turn itself off
following a failed calibration attempt.
3.6.2.3 Causes for span cal failure
Span calibration failures can be caused by:
1. Expired calibration gas.
2. Calibration gas whose concentration fails
to match the concentration expected by
the instrument.
3. Inappropriate regulator. The ToxiPro
must be calibrated using a 1.0 liter/minute
fixed flow regulator.
4. Sensor
failure.
3.7
Fresh air/zero calibration in a
contaminated atmosphere
To perform a fresh air calibration in a
contaminated atmosphere, it is necessary to
use special calibration gas, whose
composition is identical to that of fresh air.
Sperian Instrumentation offers the “Zero Air”
calibration gas cylinder as part number 54-
9039, which contains 0 PPM toxic gas and
20.9% oxygen.
1. Apply “Zero Air” calibration gas to the
instrument as shown above in figure 3.4
for at least 15 seconds or until the
readings fully stabilize.
2. Perform the fresh air/zero calibration
procedure as described in section 3.3
while continuing to flow gas to the sensor.
3. Once the fresh air/zero calibration is
complete, disconnect the calibration
assembly. If the ToxiPro is equipped with
a toxic gas sensor, proceed to the span
calibration procedure if necessary as
described in section 3.5.
4. Maintenance
4.1 Replacing
batteries
Removal or
replacement of the lithium battery in
potentially combustible atmospheres may
