How does a CO detector
work?
There are three basic types of CO sensors
metal oxide, biomimetic and electrochemical. Each is
discussed in the
How does a CO detector work.xls chart. Note that
while there may be performance differences between
these technologies, all detectors are tested and
approved for their operation.The retail cost of a
detector will generally relate to the number of
features included and its warranty conditions. There
are performance differences between these detector
types. However, changes to the CO standards should
soon result in all detectors, regardless of detector
type, having to undergo extensive testing. All will be
certified to operate under different environments
(various chemical exposures, different relative
humidities, etc.) satisfactorily if they meet the
standards.
Carbon Monoxide
Alarm Features
Carbon monoxide alarms have a
variety of different features. Before you buy one,
take a few minutes to identify the features that will
best serve your needs.
Some
features to check before you buy:
- AC or battery operation
- UL or CAS Listing
- Purchase price
- Yearly sensor and/or
battery replacement cost
- Consumer evaluations
- Reliability of the
company
- Reset features and time
it takes to reset and clear
- Digital readout
- Capacity to be wired
with other alarms
- Sensitivity
- Memory and peak level
functions
Combination Smoke and CO Alarm Technology
Two sensors in a single alarm. Separate
sensors monitor the air for smoke and carbon
monoxide.
Digital
Display
Shows elevated levels of CO present in the air
in parts per million (ppm). During an alarm, this
readout can help investigators determine how serious
the problem is.
Peak
Level Memory
Remembers the maximum level of carbon monoxide
that was present. This is important information
about maximum exposure to assist investigators,
emergency responders, or repair technicians to
determine if the levels of carbon monoxide are
reduced before the response to an alarm.
Hard-Wired (Electrical) Powered With Battery Back-Up
Wire it in. The alarm will be as permanent as a
hard-wired smoke detector.The CO alarm must have a
battery back-up in order to protect you from the
presence of carbon monoxide that is generated from
portable devices such as generators or kerosene
heaters during electrical outages.
Plug-In
(Electrical) Powered With Battery Back-Up
Plug it in! Just plug the CO alarm into a 120
VAC electrical outlet that isn't controlled by a
switch or dimmer. The CO alarm must have a battery
back-up in order to protect you from the presence of
carbon monoxide that is generated from portable
devices such as generators or kerosene heaters
during electrical outages.
Battery
Powered
Quick and easy use for almost anywhere. Ideal
for areas where you don't have available electrical
outlets. Remember to change your 9-volt battery in
the spring and fall daylight savings time changes.
Low
Battery Warning "Chirp"
Alerts you when the battery is low. The alarm
will "chirp", reminding you to change the battery.
Remote Control Test /
Silence
Allows you to ensure your CO alarm is
functioning properly. Test or silence your CO alarm
using most TV or VCR remote controls.
Test / Silence Button
One button performs two functions. In Test
mode, it checks the horn and alarm functions. During
an alarm, it activates the Silence Feature. Press it
to temporarily silence the alarm.
Why do I need an a Carbon Monoxide alarm?
The U.S.
Consumer Product Safety Commission identified
Carbon Monoxide as the leading cause of gas poisoning
deaths in the U.S. Thousands of cases of illness,
brain damage and death could be prevented if all homes
had CO alarms.
What type of alarm should I purchase?
Choose an
alarm listed with the Underwriters Laboratory (UL) or
Canadian Approval Services (CAS). The alarm sounds a
shrill warning before the levels of Carbon Monoxide
become immediately dangerous. Alarms cost $30 to $80.
Where should I place my alarm?
Carbon
Monoxide is lighter than air. CO2 and O2 are products
of complete combustion, CO is produced when there is
incomplete combustion. If all 3 gases are spilled
into an area the CO2 Carbon Dioxide will drop to the
floor and the lighter CO Carbon Monoxide will always
rise to the ceiling.
Another way to
explain this is to compare it to smoke from a fire.
Visible smoke from a fire is a particulate which is
heavier than air, but it rapidly rises to the ceiling
because of the heat. The same applies for CO spilled
from an appliance, it will rise to the ceiling and
will always be at a higher concentration near the
ceiling.
Molecular weight of:
Carbon Monoxide----->28.01
Lighter
Nitrogen----------------->28.0134
Air------------------------->28.975
Oxygen------------------>32.00
Carbon Dioxide------->44.01
Heavier
Alarms should
be located near each sleeping area. The alarm must
be located where Carbon Monoxide can reach it, and
where it will awaken persons sleeping in the
dwelling. Homes with several sleeping areas will
require multiple alarms. Locate additional alarms
near fossil fuel appliances. Do not locate an alarm
in a garage, kitchen or furnace room. CO alarms
should be at least 15 feet from the furnace, water
heating or cooking appliances. Do not mount them in
dusty, dirty or greasy areas, or in extremely humid
areas. Read and follow installation instructions
furnished with the alarm.
What should be done if an alarm sounds?
EVACUATE and
call 911. Make certain to account for everyone. Let
the Fire Department determine if there is Carbon
Monoxide in the home. If there is no CO present,
follow directions supplied with the alarm.
What do I do if there is Carbon Monoxide in my home?
DO NOT IGNORE
THE ALARM. Find out what caused the alarm. Contact
your heating contractor for help in tracking down the
CO source. Do not assume that because you cannot see,
taste or smell anything, that there is no problem. CO
has no color, taste or odor. Episodes of CO leakage
can be sporadic and hard to detect. Be persistent.
Field studies indicate there are few, if any, "false"
alarms. Be certain there is always an operating alarm
in any house where an alarm has sounded. It is
important to respond to the alarm before continued
exposure disables the occupants.
How do I know if the concentration is low or high?
Most CO alarms
emit a loud, annoying sound. Alarms listed by UL
sound only at levels above generally accepted safety
levels. You will hear it. Some alarms have a digital
readout, which reports the CO levels. But very low CO
levels, those which cause chronic health problems,
must be measured using professional instruments.
Still other alarms have a color sensor, which can be
evaluated by trained technicians.
How do I maintain and test the alarm?
Read and
follow all instructions. In general, most alarms
should be vacuumed at least twice a year, and tested
every week. Most alarms have a test button which is
pressed until a loud noise sounds. If the alarm fails
to test properly, have it repaired or replaced
immediately.
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