Carbon Monoxide Alarm User Manual

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(3) Plug in the charger.
(4) It is possible to verify that the PhD
2
is properly
charging by turning the instrument on while
connected to the battery charger and looking at the
meter display. If the battery charger is functioning
properly the screen will briefly display battery voltage
(V bat) and the current delivered by the charger (Ich).
Charging is correct if Vbat is greater than 4 Volts and
Ich is greater than 100 mA. (If a battery is fully
charged, this screen may not appear, or Ich may be
lower than 100 mA.)
(5) Press the MODE button for three seconds to turn the
instrument off.
(6) A complete charge requires approximately 8 hours.
The PhD
2
detector must not be
used in a hazardous area when the battery is being
charged.
The PhD
2
is Classified by Underwriters Laboratories,
Inc. and the Canadian Standards Association as to
Intrinsic Safety for use in Hazardous Locations Class
I, Groups A, B, C, & D. This classification is voided
while the PhD
2
is operated while connected to the
battery charger in hazardous areas.
2.4 Methods of sampling
The PhD
2
may be used as either a "Diffusion" or
"Sample-Draw" type monitoring device.
In normal operation, the PhD
2
detector is worn on the
belt, used with its shoulder strap, or held by hand. Once
turned on, the PhD
2
monitors continuously. The
atmosphere being measured gets to the sensors by
diffusing through vents in the sensor compartment cover.
Normal air movements are enough to carry the sample to
the sensors. The sensors react immediately to changes
in the concentrations of the gases being measured. This
type of "diffusion" operation monitors only the
atmosphere that immediately surrounds the detector.
It is possible to use the PhD
2
to sample remote locations
by using a sample-draw kit. Two sample-drawing kits are
available. In each case the sample is drawn in through a
probe assembly, and ducted through a length of hose
back to the instrument. One type of kit uses a hand-
operated squeeze-bulb to draw the sample through the
hose, the other uses a battery-operated continuous
mechanical pump. A hand-aspirated sample-draw kit is
included as an accessory with every PhD
2
.
2.4.1 Using the hand aspirated sample
draw kit
(1) Connect the slip-on sample draw cup with the
squeeze bulb and hose assembly. (Connect the end
of the hose closest to the bulb to the sample draw
cup.) Connect the other end of the hose to the
sample probe. Screw one or two probe extenders
into the barrel of the sample probe.
(2) Remove the PhD
2
from its protective vinyl carrying
case and slip the sample draw cup over the end of
the instrument.
(3) Cover the end of the sample draw probe assembly
with a finger, and squeeze the aspirator bulb. If there
are no leaks in the sample draw kit components, the
bulb should stay deflated for a few seconds.
(4) Insert the end of the sample probe into the location to
be sampled.
(5) Squeeze the aspirator bulb several times to draw air
from the remote location to the sensor compartment.
Allow one squeeze of the bulb for every three feet
of sampling hose.
(6) Note the gas measurement readings.
Hand aspirated remote sampling
only provides continuous gas readings for the area in
which the probe is located while the bulb is being
continuously squeezed. Each time a reading is
desired, it is necessary to squeeze the bulb a
sufficient number of times to bring a fresh sample to
the sensor compartment.
2.4.2 Using the battery operated (slip-on)
sample draw pump
Use of the slip-on battery operated pump allows the PhD
2
to continuously monitor remote locations.
CAUTION
: Never perform remote sampling with
the PhD2 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, contaminants may cause
damage to the pump, sensors and internal
components of the PhD2.
The sample draw pump includes a unique pressure
sensor designed to protect the PhD
2
from exposure to
water or other liquids. If there is a change in pressure in
the sample draw assembly due to fluid intake, the pump
immediately shuts down. After a few seconds audible
and visual alarms indicating a low flow condition will also
be activated.
Note: Make sure that the sample draw tube is not
inserted into a fluid horizontally or at a low angle.
The pressure sensor in the sample draw pump is
designed to detect changes while the sample-draw probe
is being held in a vertical position. If the probe is held
horizontally or at a low angle when inserted into a fluid, a
pressure drop sufficient to cause the pump to shut down
may not be generated.
In order to avoid potential damage, care must be taken to
keep the probe vertical any time fluids might be present.
To operate the sample draw pump: