Know the Difference: Smoke Detectors

Posted on August 8, 2012 7:00 am : Blog

There are two main types of smoke detectors: ionization detectors and photoelectric detectors. A smoke alarm uses one or both methods, plus a heat detector. The devices may be powered by a 9-volt battery, lithium battery, or 120-volt house wiring.

Ionization Detectors
Ionization detectors have an ionization chamber and a source of ionizing radiation. The source of ionizing radiation is a minute quantity of americium-241 (perhaps 1/5000th of a gram), which is a source of alpha particles (helium nuclei). The ionization chamber consists of two plates separated by about a centimeter. The battery applies a voltage to the plates, charging one plate positive and the other plate negative. Alpha particles constantly released by the americium knock electrons off of the atoms in the air, ionizing the oxygen and nitrogen atoms in the chamber. The positively-charged oxygen and nitrogen atoms are attracted to the negative plate and the electrons are attracted to the positive plate, generating a small, continuous electric current. When smoke enters the ionization chamber, the smoke particles attach to the ions and neutralize them, so they do not reach the plate. The drop in current between the plates triggers the alarm.

Photoelectric Detectors
In one type of photoelectric device, smoke can block a light beam. In this case, the reduction in light reaching a photocell sets off the alarm. In the most common type of photoelectric unit, however, light is scattered by smoke particles onto a photocell, initiating an alarm. In this type of detector there is a T-shaped chamber with a light-emitting diode (LED) that shoots a beam of light across the horizontal bar of the T. A photocell, positioned at the bottom of the vertical base of the T, generates a current when it is exposed to light. Under smoke-free conditions, the light beam crosses the top of the T in an uninterrupted straight line, not striking the photocell positioned at a right angle below the beam. When smoke is present, the light is scattered by smoke particles, and some of the light is directed down the vertical part of the T to strike the photocell. When sufficient light hits the cell, the current triggers the alarm.

Which Method is Better?
Both ionization and photoelectric detectors are effective smoke sensors. Both types of smoke detectors must pass the same test to be certified as UL smoke detectors. Ionization detectors respond more quickly to flaming fires with smaller combustion particles; photoelectric detectors respond more quickly to smoldering fires. In either type of detector, steam or high humidity can lead to condensation on the circuit board and sensor, causing the alarm to sound. Ionization detectors are less expensive than photoelectric detectors, but some users purposely disable them because they are more likely to sound an alarm from normal cooking due to their sensitivity to minute smoke particles. However, ionization detectors have a degree of built-in security not inherent to photoelectric detectors. When the battery starts to fail in an ionization detector, the ion current falls and the alarm sounds, warning that it is time to change the battery before the detector becomes ineffective. Back-up batteries may be used for photoelectric detectors.

Do Not Block Fire Extinguisher!

Posted on August 1, 2012 7:00 am : Blog

Our ABCO technicians and field reps continually happen upon fire extinguishers that are inaccessible. Here are a few more examples that highlight awareness about the need to be aware of fire extinguisher placement safety.

Blocked by a cabinet

In a closet

Blocked by curtains or drapes

Blocked by a ‘Wet Floor’ Cone

Mounted too high and blocked by a desk

The primary function of portable fire extinguishers is to provide an effective means of extinguishing small fires before they can become too large for the average person with the proper training to extinguish the fire. The use of portable fire extinguishers is highly effective on small fires when used properly and can avoid large property losses and even loss of life. This equipment is the property owners best chance of saving property and should be a high priority for all property owners to make sure they are in the proper locations and available for use. They must be well maintained at all times.  Positioning of fire extinguishers in commercial applications is oftentimes overlooked. ABCO wants to take extra precautions in educating our customers on proper placement.


Traveler Safety Tips

Posted on July 25, 2012 7:00 am : Blog

Ask yourself these 10 questions when you’re staying at a hotel

1. Who’s at the door? Look first, and then open the door.

2. Returning Late? Use the main entrance to the hotel.

3. In for the night? Make sure to lock the hotel door.

4. Where is your hotel key? Keep it on you at all times.

5. Who knows your room number? Only allow you and your companions to know.

6. Are you an attention hog? Try to avoid displaying cash and jewelry.

7. Is he a stranger? Don’t ask strangers to join you in your room.

8. Where are your valuables? Hide them in the safety box provided by the hotel.

9. Could someone access your room? Lock windows and connecting doors.

10. Have you seen any suspicious activity? Contact the front desk.

Fire Extinguishers – Installation And Service

Posted on July 11, 2012 7:00 am : Blog, Safety and Prevention

Here are some tips from our ABCO service technicians about fire extinguisher installation and service. These tips might be useful to you as you complete your own in-house safety check. Contact us with any questions!

Tips on installing a fire extinguisher:

• Fire extinguishers shall not be obstructed or obscured from view. Place in full view.

• All fire extinguishers shall be properly mounted and hung with proper manufacturer’s wall hook.

• Install fire extinguishers having a gross weight not exceeding 40 lbs., so that the top of the fire extinguisher is not more than five (5′) feet above the floor.

• Fire extinguishers having a gross weight greater than 40 lbs., shall be installed so the top of the fire extinguisher is not more than three and a half feet(3.5′) above the floor.

• In no case shall the clearance between the bottom of the fire extinguisher and the floor be less than four (4″) inches.

Tips on ABCO’s fire extinguisher services:

• Remove the fire extinguisher from the wall hook.

• Dust and/or clean the fire extinguisher.

• Replace the safety seal and check the pull pin for corrosion and ease of removal.

• Check the nomenclature label for gross weight, then scale the fire extinguisher, and invert to fluff the chemical (dry chemical extinguishers only).

• Examine the fire extinguisher for obvious physical damage, corrosion, leakage, remove nozzle, and check for any blockage.

• Verify the pressure gauge and reading or indicator in operable range or position.

• Check all fire extinguishers for six year maintenance and/or last hydrostatic testing date, whichever is applicable.

• Return the fire extinguisher to its wall hook and re-tag with new annual inspection tag facing forward with technician’s initials.

Contact us at 1-800-875-7200 with questions and talk to one of our service/support personnel about your fire extinguishers.

ABCO provides fire safety products that protect life and property.


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