NBSIR 76-1028

A New Concept for Automatic

Detection and Extinction of

Fires

D. Lay

Verband der Sachversicherer e. V. Cologne, West Germany

Translated for: Center for Fire Research

Institute for Applied Technology

National Bureau of Standards

Washington, D. C. 20234

March 1976

Final Report

U S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

NBSIR 76-1028

A NEW CONCEPT FOR AUTOMATIC

DETECTION AND EXTINCTION OF

FIRES

D. Lay

Verband der Sachversicherer e. V. Cologne, West Germany

Translated for: Center for Fire Research

Institute for Applied Technology

National Bureau of Standards

Washington, D. C. 20234

March 1976

Final Report

U.S. DEPARTMENT OF COMMERCE, Elliot L. Richardson, Secretsry

Jannes A. Baker, III, Under Secretary

Dr. Betsy Ancker-Johnton, Assistartt Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Acting Director

PREFACE

This report is a translation of paper prepared

by D. Lay and presented by him at the Seventh

International Seminar on Problems in Automatic Fire

Detection held in Aachen, Germany, on March 5-6,

1975. The Seminar was sponsored by the Institute

for Electrical Communications Engineering in Aachen

in conjunction with the Gesamthochschule in Duisberg.

This translation has been prepared to disseminate useful information to interested fire research

personnel on a need-to-know basis and is not an

original work of the Center for Fire Research.

We express our appreciation to the author,

Mr. D. Lay for his permission and assistance in

making this information available.

We also express our appreciation to the Joint

Publication Research Service, Arlington, Va., who

provided the translation of the original paper.

Richard G. Bright

Program for Fire Detection

and Control Systems

\ Center for Fire Research

iii

CONTENTS

Page

PREFACE iii

LIST OF FIGURES vi

Abstract

.

1

1. INTRODUCTION 1

2. AUTOMATIC FIRE DETECTION 2

2.1. Two-Line Technology 3

2.2. Radiation Detectors 5

3 . THE TECHNICAL CONCEPT 6

4. CONCLUDING REMARKS 11

5. REFERENCES 12

V
LIST OF FIGURES

Page

Figure 1. Automatic CO2 Extinguishing System 13

Figure 2. Buildup of the Extinguishing Concentration

with Extinguishing Agent Halon 13

Figure 3 . Exemplary Embodiment for Automatic Control

of Extinguishing Systems with Gaseous

Extinguishing Agents 14

Figure 4. Exemplary Embodiment for Automatic Control

of Sprinkler Systems 14

vi
A NEW CONCEPT FOR AUTOMATIC DETECTION

AND EXTINCTION OF FIRES

D. Lay

Abstract

The use of automatic fire detectors to

trigger fire extinguishment systems has gone on

for many years. Systems of this type use a

variety of extinguishing agents including water,

carbon dioxide and, most recently, the halogenated agents.

AutOTnatic extinguishing systems with practically an unlimited supply of agent suffer from

the fact that these systems often continue in

operation long after the fire is out resulting in

additional damage. This doesn't occur with those

systems having limited supplies such as carbon

dioxide systems and the like. However, these

systems are only successful if: (1) their original

design was correct; (2) no unanticipated changes

are made in the area or materials to be protected;

and (3) extinguishment commences at a time when

successful extinguishment is possible.

This paper describes how the disadvantages

enumerated above can be avoided, to a lar'ge

extent, with a modified design for permanentlyinstalled, automatic extinguishing systems and how

systems can be provided which will only discharge

extinguishment at the proper time and in the

proper amount.

Key words: Automatic sprinklers; carbon dioxide;

fire detection; fire extinguishment; flame

detection; heat detection; smoke detection.

1 . INTRODUCTION

In addition to pure fire detection systems, systems have

also existed for years which not only detect a starting fire,

but at the same time or a short time later also activate an

extinguishing system. Because of the great significance

attached to automatic fire detection systems in these combined detection and extinction systems, this paper is first

of all occupied with problems connected with automatic fire

1
detection. Then a technical concept will be indicated, by

means of which fires can be reliably sensed, detected, and

extinguished by appropriate extinguishing systems.

2. AUTOMATIC FIRE DETECTION

Hardly any other topic is discussed so frequently at

national and international fire detection seminars as that of

the error behavior of automatic fire detection systems. Such

discussions are indeed motivated by the fact that, due to the

constant increase in fire detection systems, the number of

false alarms has also risen proportionately. Public fire

departments are affected in the first instance, but also

affected are those who operate fire detection and extinction

systems, who must bear the cost not only for operating and

maintaining the systems, but additionally for financial

expense caused by false alarms.

There have long been indications that expense caused by

false alarms will increase severely. Possibly, this cost

will soon be so great that, when it is added to the financial

expense for installing fire detection system$, that it will

no longer stand in a proportionate relationsjlip to the usefulness of the system. The manufacturers of fire detection

devices were, therefore, well advised not to be closed-minded

towards the justified objections of the localities concerned,

but to search for suitable ways to reduce the number of false

alarms, cimong other ways by using new technology. The result

of such efforts are then devices by means of which certain

causes of false alarms can at least be partially excluded.

Still , . economically-feasible , technically-practical embodiments, which affect a noticeable reduction of false alarms or

remove them completely, have not become known. This is

particularly valid for automatic fire detectors, which unfortunately not only give an alarm when fire characteristics are

present, but are also known to set off an alarm when disturbances occur that resemble fires. Autcanatic fire detectors,

therefore, are properly considered the most critical part of

a fire detection system, as far as false alarms are concerned.

If, today, the technical possibility existed to remove

the influence of disturbances by an economically-defensible

change in the detector, e.g., by exchanging certain construction elements, there would be no question at what place the

"lever" should be applied. But such solutions are unknown,

so that a better interference-use behavior of fire detectors

can be achieved only by changing their triggering threshold

value. It need not be specially stressed how problematical

it is to reduce the number of false alarms triggered by

2
interferences, through changes in the triggering threshold

value, without thereby, also simultaneously shifting the time

at which true fires are recognized so that the alarm message

incurs no impermissible delay for beginning the extinguishing

operations. Obviously, isolated consideration of individual

fire detectors does not result in new knowledge. It is,

therefore, necessary to include not only the detector but the

entire fire detection system in the considerations, and to

consider its function also in connection with the requirements of defensive fire protection. Prominent domestic and

foreign firms have followed this route for some time, and

have thereby arrived at quite useful, but still — as I

believe — not in every respect satisfactory results. This

also pertains to such fire detection systems, among others,

where a definite alarm organization is provided, by means of

which manual activation of automatic alarm transmission is

given to responsible personnel. Since the human person was

recognized quite early as an unreliable link in the chain of

necessary measures for fire protection, and was largely

excluded frOTi this chain, a large measure of freedom in

decision and action is here again granted to him, so to speak

by the back door.

In view of the high property values which are today

under surveillance by automatic fire detection systems, it is

understandable that the German Fire Underwriters want to

avoid the risk of delayed alarms, because the magnitude of

property damage resulting from such delays cannot be calculated. A useful computational factor for this cannot be

found, if for no other reason than that nothing is, of course,

less calculable than the behavior of human persons in certain

dangerous situations. Without knowing the influence factor,

only a global determination can, therefore, be made that such

an alarm organization will narrow the reduction in risk connected with the installation of an automatic fire detection

system. Consequently, it must follow that the fire underwriters can in no way grant the maximum discount customary

for detection systems, in the case of fire detection systems

with delays according to such concepts.

2.1. Two-Line Technology

The fire underwriter makes no objections against another

technical measure, already familiar for a much longer tdLme,

which is particularly considered for combined fire protection

systems. What is meant here are automatic fire detection

systems which, for safety reasons, are designed in so-called

two-line technology (cross zoning in U.S.) and which are

widely used to control and activate automatic extinguishing

systems

.

3
As practice has shown, rather few false alarms occur

under normal conditions with this technology, with which

control of the principal detector or of the extinguishing

system occurs only when in two different detection lines at

least one fire detector has given an alarm. Nevertheless,

the two-line technology has not yet been able to make itself

prevalent in pure fire detection systems, because of the

relatively high device-and-installation expense. The increased

expense could be justified only for controlling extinguishing

systems or where e.g., a high proportion of fire-like interferences occurs because of production processes, and the

undesired alarms triggered thereby cannot be avoided by other

means. This is particularly valid for fire protection systems

where point-like smoke detectors are used as fire sensing

elements.

To retain the basic sensitivity of the detection system,

the two-line technology generally connects similar detectors

with the central control in such a way that each detector is

associated with only half of its normal surveillance range,

and the same number of detectors is arranged in each detector

line. As already mentioned, false alarms of fire detector

systems and mistriggering of extinguishing systems can, in

this fashion, be substantially reduced but not completely

eliminated. The reason for this may lie in the fact that the

same type of detector is used in both detector lines, thus

e.g., smoke detectors are used in both detector lines, so

that smoke or steam, which frequently arises in production

processes, can never be prevented from accidentally triggering two detectors in different detector lines. - A detection system where different types of detectors

are used in both detector lines, thus, e.g., smoke detectors

in one and heat detectors in the other detector line, is more

suited for fire detection systems, because of its greater

reliability against false alarms, when public fire departments are automatically alarmed or extinguishing systems must

be activated. Here a false alarm with all its consequences

would be conceivable only when smoke interference as well as

heat-like interference occur simultaneously, or when fire

characteristics themselves appear as interferences, e.g. when

welding. Despite this advantage, the system could scarsely

attain prevalence in practice, however, because the system

sensitivity is strongly reduced, especially for high rooms,

by using heat detectors.

4
2.2. Radiation Detectors

If flame detectors, or, according to a new standard

language, radiation detectors are used instead of the relatively inert heat detectors, the two-line technology permits

realization, on the one hand, of equally high reliability

against false triggering, but on the other hand also high

sensitivity of the detection system. Furthermore, it can be

supposed with great reliability that an extinguishing system

will not be activated for smoldering fires, but only when

flames have actually formed. However, it must in this case

be presumed that radiation detectors will recognize a fire

site even under heavy smoke formation and will be able to

report it. As we have learned from Dr. Portscht at the last

International Fire Protection Seminar, this requirement,

however, is met only by such detectors whose sensitivity lies

as far as possible in the infrared [1,2] 1. In the subsequent

discussion. of radiation detectors, infrared radiation detectors are, therefore, meant in principle.

The concept would certainly Itave become prevalent because

of its gr€«t advantages, if radiation detectors would not

react by also giving an alarm with interfering radiation.

False alarms of radiation detectors caused by deceptions,

such as modulated sunlight or light from incandescent lamps,

are so frequent, however, that the cost arising from interruption of operations and initiation of fire protection can

hardly be justified. At the same time, the radiation detector

has a decisive advantage with respect to other automatic fire

detectors. It is the only detector which can sense a reliable

criterion for fire nearly with the speed of light and can

give an alarm after a short time. If it could not be deceived

by interfering radiation sources, extinction processes could

be initiated by such detectors at precisely the right time,

that is, when there is an actual fire.

The radiation detector has for this reason been utilized

on and off for several years in very special systems in the

Federal Republic, despite its tendency to trigger an alarm

even for interfering radiation. We also know from England

and Switzerland that the combination of smoke and radiation

detectors, which has been mentioned here, is used for controlling extinguishing systems. Here as there, as far as I

know, success has been achieved only sporadically in shielding radiation detectors from interfering radiation in such a

way that no false alarms occur. Of course, these are not

absolutely critical in application of two-line technology,

Numbers in brackets refer to the references listed at the

end of this paper.

5
because the simultaneous occurrence of two different interferences and their triggering of an associated extinguishing

system can scarely be counted on. But every alarm entails a

certain disturbance and interference with the course of

operations until the state of affairs is clarified. From

this there not infrequently arises annoyance and dissatisfaction for the operators, despite effective detection or extinction systems. This surely also explains why this technology

could not, until now, gain a solid footing in the Federal

Republic

.

In view of the large advantage of being able to very

quickly sense and detect fires at the first occurrence of

flames, it nevertheless seems rewarding to give a thought to

the question whether radiation detectors cannot be used, despite their tendency to false alarms, in automatic fire detection systems, and here primarily in those that control

automatic extinguishing systems. Their use would have to be

such that their disadvantage would not have an interfering

effect on the system in question. This requirement can be

partially realized — this has already been established — by

using radiation detectors in one detection line but detectors

of a different type in a second line, and by connecting these

electrically and hooking them up with the fire detection

center in such a way that an attached main detector or extinguishing system is triggered only when at least one detector

per detector line gives an alarm signal. In addition to

radiation detectors, it is preferable to use smoke detectors

because of their relatively high sensitivity or, should these

be unsuitable because of the presence of smoke*-like interferences, to use heat-differential detectors.

3. THE TECHNICAL CONCEPT

In the following, I now wish to present a concept which

should meet the posed requirement even more fully. To make

things clearer, figure 1 shows you a block circuit diagram

of a combined detection and extinction system. Please do

not look for a change in known techniques in the structure

which is schematically shown here; for there are none. The

difference from currently used techniques simply lies in the

fact that the signals of the various fire detectors (in the

diagram, the signals of the smoke and radiation detectors)

are evaluated differently in the fire detection center under

certain suppositions.

Differing electrical maintenance of the individual

detector types or of the two detector lines means that false

alarms from radiation detectors can no longer have interfering effects on the system, as far as human calculation can

6
determine. This means in the first instance that the trigger

action of a radiation detector may not set off a fire alarm

in the central station; its triggering may consequently only

be considered when a smoke detector or, under some circumstances, a heat detector, has triggered previously. Triggering radiation detectors must, therefore, be automatically

reset after each fire signal, inasmuch as an alam signal was

not previously given by a smoke or heat detector. This

statement also indicates that fire signals from smoke or heat

detectors are evaluated in familiar fashion, and thus must be

processed electrically in such a way that they are indicated

at a suitable site and lead to internal or, under appropriate

circumstances, to external alarm to locations providing aid.

It is understood as a matter of course, that a fire

detection system with the performance characteristics proposed here must be adapted to local circumstances just like

every other surveillance system. This is valid particularly

for choosing requirements for connecting to the fire department. This can also be realized with a new concept in such a

way that, supposing a short extinction delay, the principal

detector goes off only when the fire characteristics of smoke

and flame occur at the same time. A quite reliable opportunity is thereby afforded for alarming the fire department

only when flames occur and are reported by the radiation

detector. As an autanatically operated guard, the radiation

detector in this case takes on the task of a reconnoitering

troop, so that such systems have the advantage, but not the

disadvantages, of the initially-mentioned alarm organization.

Such special fire detection systems are more advantageous and also more interesting from the side of costs,

especially when automatic extinguishing systems are activated

thereby. Indeed they are suitable not only for the release

and control of the extinction agent of the common extinguishing systems, but beyond this they have the additional

advantage that their use avoids the basic disadvantages of

conventional extinguishing systems. With extinguishing

systems using limited amounts of extinguishing agent and

using extinguishing agents such as carbon dioxide and the

halons, such disadvantages lie in the fact that the systems

bring the desired success only when all local circumstances

have been appropriately and correctly taken into account in

the design of these systems. Some local circumstances which

should be taken into account include: (1) room utilization,

(2) the influences on which the design is based not changing

after the systems have been set up, and (3) that extinction

is initiated at a point in time at which successful extinction

is still possible. It is a further disadvantage that the

abovementioned extinguishing systems have available only one

"shot of extinguishing agent," when the manually-operated,

7
subsequent flooding apparatus is disregarded. In practice,

this means that every building equipped with these extinguish-;

ing systems can burn down when the first attempt at automatic

extinction is unsuccessful or when rekindling takes place

from glowing pockets and human assistance in extinguishment

is not available.

For extinguishing systems with practically unlimited

quantities of extinguishing agent and for the extinguishing

agent water (e.g., sprinkler systems), disadvantages can

result from the fact that the system is not turned off at the

proper time after successful extinction, and the extinguishing agent, flowing out unnecessarily, causes greater damage.

You may perhaps be surprised when I now tell you that

all these disadvantages can be removed with already known

detection technology and with a further, relatively simple

circuit-technological measure. It turns out that the radiation detectors must only be given the opportunity, for

certain time intervals, of checking the success of extinction.

When extinguishing systems with gaseous extinguishing agents

are connected, this can be simply achieved by resetting the

radiation detectors after the flooding period is completed

and after an additional predetermined time, which I will call

the effectiveness time. The success of extinction is checked

with the aid of the radiation detectors after the effectiveness time of the extinguishing agent. According to our present experience, this time should lie between 10 and 15

seconds. If a radiation detector determines that after this

time its triggering conditions are still fvilfilled, which

means that flcimes are still present, a second installment of

extinguishing agent is immediately called forth by the control apparatus, the same amount as used during the first

extinction. If extinction should fail even after this second

extinction, repeated extinctions can follow automatically for

as long as the supply of extinguishing agent lasts.

The principle of automatic follow-up extinction ensures

that the extinguishing process is, in case of need, repeated

at the right time, and a further defined amount of extinguishing agent is demanded from the supply of extinguishing

agent. This correspondingly increases the concentration in

the area to be extinguished. This connection is once again

shown graphically in figure 2.

I also do not wish to hold back from you two exemplary

embodiments. For this reason, I will show you a simple

current plan for a small additional device, with which even

older systems can be converted with a few adjustments in the

circuit technology, so that they, too, will have the cited

performance characteristics (sete fig. 3). The additional

8
device is suitably housed either in the housing of the fire

detection center or in that of the control apparatus. Connection points 1 and 2 are brought to the detection line of

the smoke or heat detectors, through a potential-free contact

on the alarm relay (ALi), which is generally present in fire

detection centers. Points 3 and 4 are brought to the detection line of the radiation detectors, through a corresponding

contact on the alarm relay (AL2)

.

Let us now assume that alarm relay (AL2) is energized by

an alarm signal from the radiation detector. Contact AL2

closes, whereby the reset relay (RU) pulls over Ci for a short time ('*'l s) , and resets the detector line for the

radiation detectors into their normal operating condition,

with the aid of its potential-free contacts ru2.

On the other hand, if a smoke or heat detector gives an

alarm signal before the radiation detector, the alarm relay

(ALi) is activated, and through its' contact, also the relay

(AR) . The latter — if required because of certain conditions —r goes into self -maintenance by closing its contact ari

.

With arj, contacts ar^ and a.r ^ close also, so that now the

alarm relay (AS) can be activated through ar2 when a radiation

detector gives an alarm signal. Since contact ar^ is already

closed, the extinction command can now be given through a.r^

and as, , and thus the control apparatus can be controlled or

the extinction alarm can be given and, after the preliminary

earning time has run out, the extinguishing system can also

be released. In extinguishing systems with gaseous extinguishing agents, the extinguishing system is generally released by activating an extinction magnet (solenoid valve)

,

which is frequently excited through a relay in the control

apparatus. The connection terminal 5 must be connected to

ground potential, through a free contact of this extinction

relay, so that the reset relay (RU) is activated through 10,

diode Dj, and the combination R2C2r after each flooding, in

about 12 s (the effectiveness time) , and thereby resetting

the radiation detectors, as already described.

If the first attempt at extinction should not be successful, the extinction process is repeated by a new signal

from the radiation detector, and under appropriate circumstances is continued by further signals until the fire is

definitively extinguished or the supply of extinguishing

agent is used up.

In contrast to extinguishing systems with gaseous extinguishing agents, there need surely be no fear with sprinkler

systonns that the supply of extinguishing agent can be exhausted. Here the extinguishing system often still remains

functioning long after the fire has been extinguished, so

9
that the emerging water in many cases causes great consequential damage. As already mentioned, this disadvantage too can

be removed relatively simply by means of the detection system.

Care need only be taken that the input of extinguishing agent

be turned off when the fire signals of the radiation detector

cease, but that the extinguishing system, on the other hand,

is again activated when the fire again develops anew in this

operating condition. Technically, this can be realized by

changing and complementing the electrical circuit of the

described additional device, and by building a commercial

fitting into the sprinkler system.

An example of the required technical-circuit change is

shown in figure 4, where account has been taken of the fact

that sprinkler systems are selectively operating extinguishing systems, whose extinguishing agent is released not by an

automatic fire detection system, but automatically through

its own temperature-sensitive elements.

i The diagram shown, therefore, illustrates only the

essential circuits, which are required for automatic control

of extinguishing agent input. Thus all special devices, such

as smoke detectors, as well as their alarm relays and circuits

which are required only for early alarm but not for the

extinguishing process or its control, can be dispensed with.

The diagram is further conceived in such a way that the

sprinkler system does not become incapable of functioning by

disturbances in the connected electrical circuits, if it is

presupposed that at least two radiation detectors are used

per sprinkler system, that these are protected against the

effects of heat, and that a break in the wire or a short

circuit in the detector line is evaluated as an alarm criterion. In the normal operating state, the blocking valve is

therefore always open, so that even failure of the electrical

energy supply, of the extinguishing agent control, or another

electric defect in the conduction system, cannot have a deleterious effect. Through condenser C3, provision is therefore

also made, that the extinction relay is brought into the

"extinguish" position, when the supply voltage is applied,

so that turning off the sprinkler system is possible only

when a sprinkler bursts and when a plus potential reaches

the circuit R1+C2 through contact SP.-K of the alarm valve of

the sprinkler system. Triggering radiation detectors then,

only affect quick activation of the reset relay (RU) , through

contact al2 of their alarm relay. They thus bring the detector line again into the normal operating state. Only after

the sprinkler system is released (contact SP.-K closed),

capacitor is discharged, upon resetting the radiation

detectors through Di and R2. Thus the field effect ttansistor (T^ ) cannot become conducting. On the other hand, if the

signals from the radiation detectors remain absent, a charge

10

I
current can flow through R<4 to C2 r and the required triggering

threshold of Tj can be reached. In this case, the pulse given

off by Tj makes T2 also conducting, and brings the anchor

position of extinction relay (LO) into the position "off."

4. CONCLUDING REMARKS

The results, which we were able to gather in the past

through experiment and through experience with local extinguishing systems of a new concept, are thoroughly positive.

We, therefore, also believe that the effectiveness and reliability of autOTiatic extinguishing systems can be significantly increased by the new concept.

But further experiments will still have to show whether

the system is actually practicable. Should this be the case,

the process would have the following advantages, among others.

1. The occurrence of the fire itself determines the

required amount of extinguishing agent and thus,

within certain limits, the concentration of extinguishing agent in the spaces to be protected. As a

result, the mathematically-determined design of

extinguishing systems with open nozzles and only

a limited supply of extinguishing agent does not

lead to failure with risks whose requirement for

extinguishing agent has not yet been determined by

experience, as when too small a concentration of

extinguishing agent has been chosen because of

ignorance of the required eunount of extinguishing

agent. Through automatic follow-up extinction, the

extinction process is in fact repeated at the right

time in cases where it is needed. Another precise

euaount of extinguishing agent is taken from the

supply of extinguishing agent, which increases the

concentration of extinguishing agent in the protected area.

2, Another advantage of this system conception is that

errors in the calculation of amounts of the extinguishing agent to be used do not jeopardize success

of extinction for risks not recognized during

testing because the extinguishing system always

automatically demands as much extinguishing agent

as necessary to successfully complete extinction.

Damaging influences result from use-changes in

buildings or rooms, for example, by the storing of

materials with other fire characteristics or by the

changing of construction features, such as, the

addition of openings in walls and ceilings.

11
Frequently/ with automatic extinguishing systems,

using a limited supply of extinguishing agent can

lead to the originally calculated amount of extinguishing agent and concentration not being able to

control the course of the fire. These damaging

influences are reduced in the same fashion. The

procedure, furthermore, guarantees that extinction

does not happen at a point in time when extinction

is unnecessary, i.e. , one avoids supplying extinguishing agent at the first sign of smoke, when the

fire would not be extinguished to such an extent

that another flame-up would be possible later, and

then, at that time, no extinguishing agent would

be any longer available.

3 . It is an advantage that the basic conception can be

combined with present automatic fire extinguishing

systems. Thus, its use does not require, among

other things, a multiple increase in the supply of

extinguishing agent and in the concentration of

extinguishing agent. Therefore, no basic increase

in expense is required for the extinguishing system

to guarantee the extinction effectiveness of the

system even with the special, previously not foreseeable, cases* The cited advantages thus need not

be purchased through an expensive new system, which

is decisive for the economy. It is, furthermore,

an advantage that already-existing extinguishing

systems can be converted without great expense, so

that they, too,, can obtain the cited advantages.

5. REFERENCES

[1] Portscht, R. , Calculation and Measurement of Extinction

Characteristics of Smoke in the Optical Spectra Region,

Congress Report for the 6th International Lecture Seminar

Concerning Problems of Automatic Fire Detection, October

4-6, 1971.

[2] Portscht, R. , Concerning the Time Behavior of Temperature

Radiation as Characteristic of a Fire, Dissertation,

T. H. Aachen (1970)

.

USCOMM-NBS-DC

12
8)

yLo&chmagnel 9 )

0

C02-8ehdlKr 10) )

Figure 1. Automatic CO. Extinguishing System

1. Smoke Detector 6. Extinction Alarm

2. Flame Detector 7. Control Apparatus

3. Smoke Detector 8. Nozzle

4. Fire Alarm 9. Extinction Magnet

5. Central Unit 10. CO^ Container

Figure 2. Buildup of the Extinguishing

Concentration with Extinguishing Agent Halon

13
r

Figure 3 . Exemplary Embodiment for Automatic

Control of Extinguishing Systems with

Gaseous Extinguishing Agents

1. Extinction Command

Figure 4. Exemplary Embodiment for

Automatic Control of Sprinkler

Systems

14
iBS-1l4A (REV. 7-73) |"^.S. DEPT. Oh COMM.

' BIBLIOGRAPHIC DATA

SHEET

1. Pl.'ULlCATION OR Ri-.t^ORT NO.

NBSIR 76-1028

2* Ciov *t Accession

No.

3. R c t'

1 p K' n ( s Ac cc s s i()n No

.

|. TITLE AND SUBTITLE

A New Concept for Automatic Detection and

Extinction of Fires

5. Publication Dftic March 1976

4« Performing Organization ^.odt*

AUTHOR(S)

D. Lay

8. Performing Organ. Report No.

PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No. 4928677

11. Contract/Grant No.

!. Sponsoring Organization Name and Complete Address (Street, City, State, ZIP)

Same as No. 9

13. Type of Report & Period Covered

Final Report

14. Sponsoring Agency Code

i. SUPPLEMENTARY NOTES

.. ABSTRACT (A 200-word or leas factual summary of most significant information. If document includes a si^ificant

bibliography or literature survey, mention it here.)

The use of automatic fire detectors to trigger fire extinguishment

systems has gone on for many years. Systems of this type use a variety of extinguishing agents including water, carbon dioxide and,

imost recently, the halogenated agents.

lAutomatic extinguishing systems with practically an unlimited supply

of agent suffer from the fact that these systems often continue in

operation long after the fire is out resulting in additional damage.

This doesn't occur v.'ith those systems having limited supplies such as

carbon dioxide systems and the like. However, these systems are only

successful if: (1) their original design was correct; (2) no unanticiipated changes are made in the area or materials to be protected; and

(3) extinguishment ccxnmences at a time when successful extinguishment

is possible.

This paper describes how the disadvantages recommended above can be

/avoided, to a large extent, with a modified design for permanentlyinstalled, automatic extinguishing systems and how systems can be

provided which will only discharge extinguishant at the proper time

'and in the proper amount.

. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name; separated by semicolons) Automatic sprinklers; carbon dioxide; fire

detection; fire extinguishment; flame detection; heat detection;

smoke detection.

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