Alarm; Over Range Alarm; Low Battery Alarm; Calibration Verification Test And Calibration - 3M 450 Série Mode D'emploi

Alarm

When the target gas concentration reaches or exceeds the alarm set point for the target gas of the detector it
will alarm. When in alarm, the audible alarm beeps and the hazard light flashes approximately every second.
On the vibrator equipped  series detectors the vibratory alarm will also activate.
The unit will stop alarming when the target gas concentration falls below the alarm set point of the unit.

Over Range Alarm

When the target gas concentration exceeds the detection range of the detector the LCD display will go blank
and the instrument will continue to alarm as described in the alarm section.

Low Battery Alarm

When the battery voltage falls to a level where the battery life is almost depleted the hazard light will flash. The
audible and/or vibratory (if equipped) alarms will not be activated.
Note: The instrument is designed to continue operating normally for at least 8 hours after the low battery
alarm indicator is activated.

Calibration Verification Test and Calibration

Ensure final calibration concentration displayed on the unit matches the certified calibration gas
concentration used. Failure to do so may produce an inaccurate reading which means that higher levels of
the gas being monitored may be present and could result in overexposure and cause sickness or death.
The following steps must be performed when performing a calibration or calibration verification test to
ensure proper performance of the detector. Failure to do so may adversely affect product performance and
result in sickness or death.
– Ensure the applicable sensor for your unit is installed in the unit.
– Calibrate prior to initial use.
– When performing a calibration or calibration verification test (bump test), only use certified calibration
gas. Do not calibrate with expired calibration gas.
– A calibration verification test (bump test) should be performed before each use.
– If the instrument cannot be calibrated, do not use until the reason can be determined and corrected.
– Do not cover or obstruct display, audible alarm opening or visual alarm cover.
– Ensure sensor inlet is unobstructed and is free of debris.
– Ensure calibration hood is removed prior to use.
A calibration verification test (Bump Test) should be performed before every use. This is done by checking
the detector's response to a known concentration of certified calibration gas. Calibration of the unit must be
performed at least every 0 days or immediately if it does not pass the calibration verification test. Sensors used
beyond the warranty period or exposed to very high concentrations of gas may require more frequent calibration.
Note: The detector has been calibrated prior to being shipped from the factory. However, to ensure it is
performing correctly, a calibration or calibration verification test must be performed prior to initial use.

Performing a Calibration Verification Test (Bump Test)

The 0 detector should be tested every time you use the detector. A calibration verification test is the only
way to effectively confirm that all characteristics of the detector and the sensors are working correctly.
Ensure that you are in a non-contaminated environment before performing a calibration verification test.
To conduct the test, attach the calibration (cal) hood on top of the sensor inlet. Ensure the calibration gas
matches the sensor installed in the instrument. Connect the hose from the gas regulator of the calibration gas
bottle to the cal hood. Turn on the gas.
WARNING
0
Compare the displayed values with those of your reference calibration gas source. Apply the calibration gas
for a period of at least 2 -  minutes to ensure sufficient response time and steady state readings. If the
measurement displayed is within ±0% of the calibration gas concentration turn off the calibration gas and
remove the cal hood. The unit is now ready for use. Otherwise a calibration should be performed.

Performing a Calibration

To carry out a successful calibration the instrument needs to be located in a non-contaminated environment.
A source of certified calibration gas is also required. The recommended certified calibration gas concentration
(span gas) is listed in the specification section of these User Instructions, and is also located on the detector
label next to the span adjustment screw. The calibration gas must be within the range of the sensor that is
being calibrated.

Calibrating Oxygen Detector Only

. Unscrew and remove the calibration port cover screw (Fig. ).
2. Place the unit in a known non-contaminated environment (20.9% vol in air).
. If the unit is reading below 20.9%, insert a flat-head end screwdriver into the adjustment screw. Then
turn the screw clockwise until the LCD display reads 20.9%.
. If the reading is above 20.9%, turn the adjustment screw counter-clockwise until the reading is 20.9%.
. If the reading does not reach 20.9% by turning the adjustment screw, the sensor has expired and must
be replaced (see MAINTENANCE section).
6. Replace the calibration port cover screw.
7. The unit is now ready for use.
Audio Alarm

Calibrating All Other Detectors

Zeroing the Detector

. Make sure that your detector is located in known non-contaminated environment.
2. Remove the zero adjustment cover screw (Fig. ).
. Insert a flat-headed screwdriver and align it with the zero adjustment screw below. Turn the zero
adjustment screw clockwise until your detector displays any number above zero.
. Next, turn the adjustment screw counterclockwise until the display reads zero and not more than /
turn beyond.
. Replace the zero adjustment cover screw.
Sensor Inlet
Calibration Port
Cover Screw

Fig.