17
temperatures. The battery may be irretrievably damaged
resulting in reduced battery capacity and voltage.
Sperian Instrumentation recommends attaching a powered
Cannonball3 charger to the NiMH instruments when not in use.
2.4.2.2 Charging guidelines for NiMH battery
The NiMH battery in the Cannonball3 should never be charged
at temperatures lower than 5
°
Celsius (40
°
Fahrenheit) or
higher than 30
°
Celsius (86
°
Fahrenheit). Charging at
temperature extremes can cause permanent damage to the
battery.
The Cannonball3 must be located in a
non-hazardous location during the charging cycle.
Charging the Cannonball3 in a hazardous location may
impair intrinsic safety.
2.4.2.3 Charging procedure for NiMH battery
1. Check that the instrument is turned off. (If it is not, press
the MODE button for three seconds until the message
"Release Button" appears.)
2. Connect the charger to the Cannonball3.
3. Plug the power supply in and check to see that the
“Power” indicator LED on the charger is lit.
4. Attach the charger to the Cannonball3. While the battery
is charging the red ‘Power’ indicator LED and the red
“Charge” indicator LED will be lit on the charger.
Note: The “Charge” LED indicator will initially light up and
remain lit for the first 15 minutes regardless of battery
pack voltage.
5. Charging will be completed in 5 hours or less, and will be
indicated by the green ‘’Ready’ indicator LED. Charging is
complete any time after the “Ready” indicator is lit.
CAUTION
To achieve optimal charge and ensure
long battery life of the NIMH battery, make sure that
charging takes place in an area where the ambient air
temperature is between 5
o
and 40
o
Celsius (40
°
and 86
°
F).
Charging the battery in temperatures above or below this
range can damage the battery and will drastically effect
battery life.
2.4.3
Low battery alarms
Note: The voltage figures given below are for Cannonball3
instruments with firmware version 1.55 and may be
slightly different for units with other versions of
instrument firmware.
The Cannonball3 includes low battery alarms that are activated
whenever battery voltage approaches a level that will soon
lead to instrument shut down. When the battery voltage is
reduced to approximately 5.15 volts in alkaline units, or 4.82
volts in NiMH rechargeable units, an audible alarm will sound,
and the display screen will indicate that a low battery condition
exists. At this stage, the low battery alarms may be silenced
for up to fifteen minutes by pressing the MODE button. After
the first low battery alarm, the alarm will sound again every
fifteen minutes until the voltage drops to the “Very Low Battery”
level.
The “Very Low Battery” level occurs when the battery voltage
drops to 5.06 volts in alkaline units, or 4.75 volts in NiMH
rechargeable units. Due to the risk of imminent shut down,
when the battery voltage reaches the “Very Low Battery” level
it is no longer possible to silence the low battery alarms. At
this point, it is necessary to either immediately leave the
hazardous area in which the instrument is being used or to
immediately install a new battery pack with a charge sufficient
to avoid the low battery alarms.
When the voltage drops to 5.00 volts in alkaline units, or 4.73
volts in NiMH rechargeable units. the Cannonball3 will display
a "Dead Battery" message to warn the user of imminent shut
down. The instrument will then automatically turn itself off.
After any low battery alarm the batteries should be replaced if
the Cannonball3 is equipped with alkaline batteries or the
battery should be recharged if the Cannonball3 is equipped
with a NiMH rechargeable battery.
2.5 Methods of sampling
Every Cannonball3 is equipped with a field-replaceable
continuous sample draw pump. Proper use of the pump and
sample probe assembly is critical to ensure proper instrument
functionality. The pump and probe assemblies are
automatically tested whenever the Cannonball3 is turned on.
Note: The maximum length of standard diameter tubing
that can be used with the Cannonball3 is 100 feet.
The Cannonball3’s sensor compartment is contained within the
instrument. The gas sample must be drawn into the instrument
by the pump through the probe assembly that is attached to
the inlet coupling on the front of the unit.
The pump in the Cannonball3 draws the air sample into the
instrument at the rate of about 1 foot per second. Once the
sample reaches the sensor compartment, allow approximately
1 additional minute for readings to stabilize. This means that
with the standard 10 feet of tubing between the probe and the
instrument, it will take approximately 70 seconds to obtain a
valid reading of the atmosphere.
Use only polyester urethane (fuel-
resistant) tubing to draw the sample into the Cannonball3.
Use of other types of tubing may cause inaccurate and
potentially dangerous readings.
The Cannonball3 is delivered with 10 feet of polyester
urethane (fuel-resistant) tubing as a standard accessory.
If replacement tubing is needed, Sperian Instrumentation’s
polyester urethane (fuel-resistant) tubing is part number
53-001.
Once turned on, the Cannonball3 monitors continuously. The
Cannonball3’s sensors react immediately to changes in the
concentrations of the gases being measured. This type of
operation monitors only the atmosphere in the immediate area
of the end of the probe assembly.
CAUTION: Never operate the Cannonball3 without the
sample probe assembly. The sample probe handle
contains replaceable filters designed to block moisture
and remove particulate contaminants. If the pump is
operated without the probe assembly in place particulate
contaminants may cause damage to the pump, sensors
and internal components of the Cannonball3.
The sample draw pump includes a pressure sensor designed
to protect the Cannonball3 from exposure to water or other
liquids. If there is a change in pressure in the sample draw
assembly due to fluid intake or other blockage, the pump
immediately shuts down. After a few seconds audible and
visual alarms indicating a low flow condition will also be
activated.
CAUTION
: Insertion of the sample draw tube into a
fluid horizontally or at a low angle may cause fluids to be
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