ASTM D6332-99(2005)
(Guide)Standard Guide for Testing Systems for Measuring Dynamic Responses of Carbon Monoxide Detectors to Gases and Vapors
Standard Guide for Testing Systems for Measuring Dynamic Responses of Carbon Monoxide Detectors to Gases and Vapors
SIGNIFICANCE AND USE
This guide provides information on testing systems and their components used for measuring responses of CO alarms or detectors subjected to gases, vapors, and their mixtures. Components of a testing system include a chamber, clean air supply module, humidification module, gas and vapor delivery module, and verification and control instrumentation.
The CO detector is tested by sequential exposure to CO and interference gases at the specified challenge concentrations. A properly functioning alarm/detector will sound upon sufficient exposure to CO but will not sound upon any exposure to interference gases consistent with applicable standards (for example, IAS 6-96 (1)6 , BS 7860, UL 2034).
SCOPE
1.1 This guide describes testing systems used for measuring responses of carbon monoxide (CO) alarms or detectors subjected to gases, vapors, and their mixtures.
1.2 The systems are used to evaluate responses of CO detectors to various CO concentrations, to verify that the detectors alarm at certain specified CO concentrations, and to verify that CO detectors do not alarm at certain other specified CO concentrations.
1.3 The systems are used for evaluating CO detector responses to gases and vapors that may interfere with the ability of detectors to respond to CO.
1.4 Major components of such a testing system include a chamber, clean air supply module, humidification module, gas and vapor delivery module, and verification and control instrumentation.
1.5 For each component, this guide provides a comparison of different approaches and discusses their advantages and disadvantages.
1.6 This guide also presents recommendations for a minimum configuration of a testing system.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For more specific safety precautionary information, see 6.2.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D6332 – 99 (Reapproved 2005)
Standard Guide for
Testing Systems for Measuring Dynamic Responses of
Carbon Monoxide Detectors to Gases and Vapors
This standard is issued under the fixed designation D6332; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D1945 Test Method for Analysis of Natural Gas by Gas
Chromatography
1.1 This guide describes testing systems used for measuring
D3162 Test Method for Carbon Monoxide in the Atmo-
responses of carbon monoxide (CO) alarms or detectors
sphere (Continuous Measurement by Nondispersive Infra-
subjected to gases, vapors, and their mixtures.
red Spectrometry)
1.2 The systems are used to evaluate responses of CO
D3195 Practice for Rotameter Calibration
detectors to various CO concentrations, to verify that the
D3249 Practice for General Ambient Air Analyzer Proce-
detectors alarm at certain specified CO concentrations, and to
dures
verify that CO detectors do not alarm at certain other specified
D3687 Practice for Analysis of Organic Compound Vapors
CO concentrations.
Collected by the Activated Charcoal Tube Adsorption
1.3 The systems are used for evaluating CO detector re-
Method
sponses to gases and vapors that may interfere with the ability
2.2 Other Standards:
of detectors to respond to CO.
BS 7860 Specification for Carbon Monoxide Detectors
1.4 Major components of such a testing system include a
(Electrical) For Domestic Use
chamber, clean air supply module, humidification module, gas
UL 2034 Single and Multiple Station Carbon Monoxide
and vapor delivery module, and verification and control instru-
Detectors
mentation.
CFR 1910.1450 Occupational Exposure to Hazardous
1.5 For each component, this guide provides a comparison
Chemicals in Laboratories
of different approaches and discusses their advantages and
disadvantages.
3. Terminology
1.6 The guide also presents recommendations for a mini-
3.1 Definitions:
mum configuration of a testing system.
For definitions of terms used in this guide, refer to Termi-
1.7 This guide does not purport to address all of the safety
nology D1356.
concerns, if any, associated with its use. It is the responsibility
3.2 Definitions of Terms Specific to This Standard:
of the user of this standard to establish appropriate safety and
3.2.1 air change rate—the volume of clean, humidified air
health practices and determine the applicability of regulatory
plus contaminants that enters the chamber in 1 h, divided by
limitations prior to use. For more specific safety precautionary
the internal volume of the chamber, expressed as air changes
information, see 6.2.
–1
per hour (h ).
2. Referenced Documents 3.2.2 chamber—an enclosed test volume composed of
2 chemicallyinertmaterialssuppliedwithamixtureofair,gases,
2.1 ASTM Standards:
or vapors, or combination thereof, having known composi-
D1193 Specification for Reagent Water
tions.
D1356 Terminology Relating to Sampling and Analysis of
3.2.3 CO alarm/detector—an alarm device consisting of an
Atmospheres
assemblyofelectricalandmechanicalcomponentswithchemi-
cal, electrochemical, solid-state electronic, or other types of
sensors to detect the presence of CO gas in specified ranges of
This guide is under the jurisdiction ofASTM Committee D22 on Sampling and
concentrations.
Analysis of Atmospheres and is the direct responsibility of Subcommittee D22.05
on Indoor Air.
Current edition approved January 1, 2005. Published January 2005. Originally
approved in 1998. Last previous edition approved in 1999 as D6332 - 99. DOI: Available from British Standards Institute (BSI), 389 Chiswick High Rd.,
10.1520/D6332-99R05. London W4 4AL, UK
2 4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from Underwriters Laboratories (UL), Corporate Progress, 333
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Pfingsten Rd., Northbrook, IL 60062.
Standards volume information, refer to the standard’s Document Summary page on AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments,
the ASTM website. 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6332 – 99 (2005)
3.2.4 sensor—the component included in the CO alarm/ 6.3 Size of the Chamber—The chamber size can be large
detector that senses CO gas. (that is, room-size) or small and depends on the number of
detectors to be tested. Detectors should be placed on a wire
4. Summary of Guide
rackorsimilarsupportingstructure.Detectorsshouldbeplaced
at least 0.1-m [4-in.] away from the chamber walls. If multiple
4.1 This guide describes components of systems for testing
detectors are undergoing simultaneous testing, they should be
CO detectors with mixtures of air and CO at different concen-
spacedatleast0.05m[2in.]fromeachother.Thechambersize
trations of CO. The systems are also used for evaluating the
required by UL 2034 is a 0.9 by 0.9 by 0.9-m [3 by 3 by 3-ft]
responses of CO detectors to mixtures of air and various gases
box, which has been found to be practical for testing several
or vapors, or both. Such systems require clean air with a
detectors at a time.
preselected level of relative humidity supplied to an environ-
6.4 Material of Construction—The chamber should be
mental chamber. Gases and vapors are introduced in the clean
made of relatively inert materials, such as glass, stainless steel,
air supply or placed directly in the chamber to achieve desired
or certain types of polymers/plastics. Materials, such as wood
chamber concentration. The components of such systems
or gypsum board, may not be appropriate because of their
include devices or modules for supplying pure air, humidifying
absorption, adsorption, and leakage characteristics. Joints
air, supplying gases or vapors, or both, to be tested, reference
should be well-sealed using inert caulking/sealing materials.
instruments for verifying concentrations of gases and vapors,
Gaskets should be used around doors and other closable
and a chamber for placing and exposing CO detectors. The
openings to achieve a good seal when closed.
guide describes various options for each component: chamber
6.5 Air Change Rate—The air change rate of a dynamic
(Section 6), clean air supply module (Section 7), humidifica-
–1
chamber should be sufficient (for example, 1 h or higher) to
tion module (Section 8), gas/vapor delivery module (Section
overcome loss of chamber air through leakage and the deple-
9), and verification and control module (Section 10).The guide
tion of test gases and vapors due to factors, such as consump-
further provides recommendations on a minimum configura-
tion through a chemical reaction or deposition.
tion for the testing system (Section 11) and reporting results
6.6 Mixing—Toprovideauniformconcentrationfortesting,
(Section 12).
the chamber air should be well mixed. With an adequate air
–1
change rate (for example, 1 h or higher), mixing can be
5. Significance and Use
achieved through proper placement and design of inlet and
5.1 This guide provides information on testing systems and
outlet ports. The design and placement should be such that any
their components used for measuring responses of CO alarms
short-circuiting of flow from inlet to outlet ports is avoided.A
or detectors subjected to gases, vapors, and their mixtures.
better alternative to promote mixing is to use a fan that is
Components of a testing system include a chamber, clean air
appropriately sized for the chamber volume. For example,
supply module, humidification module, gas and vapor delivery
3 3
mixing within a large chamber having 23-m [800-ft ] volume
module, and verification and control instrumentation.
–1
can be achieved by an 378 l-s [800-cfm] fan. Ideally, the fan
5.2 The CO detector is tested by sequential exposure to CO
should be mounted on a shaft through the chamber wall, and
and interference gases at the specified challenge concentra-
the fan motor should be external to the chamber to prevent
tions. A properly functioning alarm/detector will sound upon
contaminationandheatloadinthechamber.Ifafanisused,the
sufficientexposuretoCObutwillnotsounduponanyexposure
sensorportsshouldbeshieldedfromdirectairimpingement.In
to interference gases consistent with applicable standards (for
addition to providing a uniform air concentration, the combi-
example, IAS 6-96 (1) , BS 7860, UL 2034).
nation of air change rate and mixing should be such that it
–1
provides sufficient face velocity (for example, over1ms or
6. Chamber
–1
3.3 ft s ) at sensor head(s) through the detector housing.
6.1 Types of Chamber—There are two types of chambers—
6.7 The chamber should be able to provide accurate control
static and dynamic. In a static chamber, air and known
of temperature and relative humidity at ambient pressure as
quantities of gases are introduced and then the chamber is
indicated in Table 1. The chamber should be airtight to
sealed. In a dynamic chamber, a characterized air-gas mixture
minimize any leakage of ambient air into or chamber air out of
is continually introduced at a rate sufficient to maintain target
the system. The range of environmental conditions cited in
concentrations.
Table 1 cover ranges specified in standards listed in 2.2 and in
6.2 Hazards—In a dynamic chamber, the air exiting cham-
the literature (1). Also, UL 2034 prescribes certain time peri-
ber will contain CO and interference gases or vapors that may
od(s) to achieve target concentrations that should be adhered to
be toxic. To avoid undue exposures of toxic gases and vapors
so that undue exposures are avoided.
to occupants of the laboratory (where the chamber is located),
6.8 Discussion—The advantage of the static chamber is that
the chamber should be properly vented to outside with an
thesetupissimple,basicallyrequiringonlyasealablebox.The
appropriate stack. For a static chamber, exposures to test gases
should be avoided in operating (for example, opening) the
chamber. TABLE 1 General Specifications for Test Chamber
Specification Control Range Control Precision
Temperature –10 to 52°C [14 to 126°F] 6 0.5°C [6 0.9°F]
Relative humidity 15 % to 95 % 6 5.0 %
The boldface numbers in parentheses refer to references at the end of this (noncondensing)
standard.
D6332 – 99 (2005)
major disadvantage of the static chamber is that the gases may bed to remove CO may not be necessary. If a catalyst bed is
be consumed or generated in the chamber, resulting in an used, use a desiccant and a downstream activated charcoal
environment that is different than originally specified. For this filter to remove water vapor and oxides of nitrogen, respec-
reason,thecompositionoftheatmosphereshouldbemonitored tively, that are generated from the catalyst bed.
continuously for CO concentrations and other related param- 7.4 Alternate Clean Air Module—Air from outdoors or
eters. The dynamic chamber requires a continuous and con- from the laboratory can be conditioned and cleaned by passing
trolled supply and exhaust of air and gases to be tested but it through particulate filters to remove suspended solid par-
provides an environment that does not undergo changes as an ticles, preheat coil and a chilled water dehumidifying coil to
artifact of testing. remove excess moisture, a desiccant dehumidifier to further
dehumidify air, a catalytic bed to remove background CO, and
7. Clean Air Supply Module
an activated carbon adsorbent bed to remove volatile organic
compounds in the air.
7.1 Types—There are two approaches for obtaining a clean
7.5 Discussion—The use of prepackaged clean air requires
air supply: (1) to use a prepackaged supply of clean air; and (2)
a minimal initial investment. The laboratory shall provide for
to generate clean air by processing ambient air to remove
safe storage of pressurized cylinders. Pressurized cylinders of
impurities and moisture. This second approach requires equip-
clean air that meet or exceed specifications can be purchased
ment for removing particle and gas contaminants and moisture
through commercial gas supply vendors. However, this can
from the ambient air. Clean air can be generated to meet
become costly depending on the level of use of clean air. The
specifications for different requirements of stringency. Preas-
use of a clean air module, on the other hand, requires an initial
sembled equipment for processing ambient air is also available
investment in a compressor and filtration/dehumidification
from commercial gas supply vendors. Some details on the two
equipment. The completed module supplies clean air at lower
approaches are given below.
cost if the clean air supply is used regularly. Further, proper
7.2 Packaged Clean Air—Use of packaged air involves
selection of specifications will provide adequate repeatability
purchase of pressurized cylinders of clean air or zero air with
in testing results without undue high cost. There are various
certain specifications. Recommended specifications are: less
–3
levels of clean air that can be achieved. For testing CO
than 0.5 ppm(v) (0.33 mg m of methane equivalent) of total
–3
detectors, ultra-pure air (total hydrocarbon content < 0.1
hydrocarbons, water vapor less than 3.5 ppm(v) (2.6 mg m ),
–3
–3
ppm(v) or 0.06 mg m ) is generally unnecessary. A total
and CO less than 1 ppm(v) (1.1 mg m ). Such gases are
–3
hydrocarbon content of less than 0.5 ppm(v) (0.33 mg m )is
available from commercial vendors of pure gases and gas
considered to be adequate.
mixtures.
7.3 Clean Air Generation Module—A basic clean air gen-
8. Humidification Module
eration module has the following components: oil-less com-
8.1 Air from the clean air module is fed to a humidification
pressor, desiccant to remove moisture, particle filter to remove
module. This module controls the relative humidity of the
suspended particles, and activated charcoal filter or catalyst
air-gas mixture delivered to the chamber. Depending on the
bed, or both, to remove gaseous impurities. In addition to these
range of specifications for humidification, the humidification
components, a storage tank, high pressure lines, and regulator
module can be achieved in one of at least two ways:
are necessary. A radiative cooler may be necessary to cool
8.1.1 The simple module will contain chilled water cooling
compressed air. An example flow diagram for a clean air
coils, a reheat coil, and steam humidifier to obtain desired
generation module is shown in Fig. 1. Roo
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