1、ANSI Z21.94a-2007 (reaffirmed 2016) CSA 6.31a-2007 (reaffirmed 2016)Addenda to the First EditionANSI Z21.94-2006 CSA 6.31-2006American National Standard / CSA Standard for Automatic Flammable Vapor Sensor Systems and ComponentsStandard DeveloperAPPROVEDCSA AMERICA INC. 8501 East Pleasant Valley Road
2、Cleveland, Ohio 44131CANADIAN STANDARDS ASSOCIATION5060 Spectrum Way, Suite 100Mississauga, Ontario, Canada L4W 5N6Published - October 2007Copyright 2007Canadian Standards AssociationPermission is granted to republish material herein in laws or ordinances, and in regulations, administrative orders,
3、or similar documents issued by public authorities. Those desiring permission for other republication should consult Canadian Standards Association, 5060 Specrum Way, Suite 100, Mississauga, Ontario, Canada L4W 5N6.Copyright 2007CSA America, Inc.Permission is granted to republish material herein in l
4、aws or ordinances, and in regulations, administrative orders, or similar documents issued by public authorities. Those desiring permission for other republication should consult CSA America, Inc., 8501 East Pleasant Valley Road, Cleveland, Ohio 44131.PrefaceThe standards set forth herein apply to th
5、e first edition of the Standard for Automatic Flammable Vapor Sensor Systems and Components, ANSI Z21.94-2006 CSA 6.31-2006, and supersede corresponding standards therein. Following their preparation by the supervising Technical Advisory Group, they were accepted by the American National Standards I
6、nstitute (ANSI) and the Interprovincial Gas Advisory Council (IGAC), and subsequently approved.NOTE: Changes, other than editorial, are denoted by a vertical line in the margin.July 17, 2007American National Standards Institute, Inc.September 14, 2007Interprovincial Advisory Council Effective in Can
7、ada May 1, 2009IGAC1Part II: Performance2.2 Flammable Vapor SensitivityThe sensor or system under test shall produce a signal indicating that the flammable vapor limit has been reached, within the period of time specified by the manufacturer, but not to exceed 60 seconds, after being exposed to the
8、flammable vapor limit, when tested in accordance with the following Method of Test. Method of TestThe sensor or the systems sensor components under test shall be tested in a chamber such as the typical chamber shown in Figures 1, Typical Flammable Vapor Sensor Test Chamber (Side view external wall)
9、through 3, Typical Flammable Vapor Sensor Test Chamber (Top view), which is capable of maintaining the temperature and relative humidity conditions specified in Table VII, Temperature/RH Conditions.The accuracy and precision of the measurement test equipment shall be as shown in Table VIII, Requirem
10、ents of Flammable Vapor Measurement Test Equipment.The accuracy and precision of the test chamber shall be as shown in Table IX, Requirements of Flammable Vapor Measurement Test Chamber.The chamber shall be capable of generating and maintaining the flammable vapor at a uniform concentration througho
11、ut the test chamber equivalent to the flammable vapor limit (as specified by the manufacturer) by the injection of winter blend gasoline, through a means such as atomized into a fine mist.The chamber shall be capable of causing the gasoline vapor concentration surrounding the sensor to increase from
12、 zero percent, to the flammable vapor limit (as specified by the manufacturer) within a period of 5 seconds.The signal from the sensor or system shall be monitored throughout each test.The sensor or system shall be maintained at test condition 1 of Table VII for a minimum period of two hours or unti
13、l the sensors or systems signal does not change by 5 percent over a period of 15 minutes. There shall be no gasoline vapor in the chamber during this period.Once the sensor or system has stabilized, it shall be exposed to a gasoline vapor concentration equivalent to the flammable vapor limit. The ti
14、me required for the gasoline vapor concentration to increase to the flammable vapor limit at the sensor location shall not exceed 5 seconds. This gasoline vapor concentration shall be maintained throughout the remainder of the test. A suitable timer shall be started at the beginning of the 5-second
15、vapor establishment period. The timer shall be operated until the sensor or system indicates that the flammable vapor limit has been reached. This time shall not exceed the time specified by the manufacturer, or 60 seconds, whichever is less.This test shall be repeated at test conditions 1 through 5
16、 specified in Table VII.22.3 Continued PerformanceThe system shall demonstrate sufficient robustness to meet the requirements of the application at extreme operating conditions. The same device(s) tested under 2.2, Flammable Vapor Sensitivity, or new devices from the same production run as the sampl
17、e(s) tested under 2.2 shall be used for each section below, as specified by the manufacturer. Acceptance criteria is (1) no false trips during exposure and (2) successfully passing the requirements of 2.2 at ambient temperature and humidity when completed.Method of TestA sensor and/or system shall b
18、e subjected to each of the following tests:a. Sensor and/or systems shall be powered with rated voltage and operated continuously for 720 hours in clean air at maximum operating temperature and rated voltage.b. Sensor and /or systems shall be subjected to 100,000 on-off cycles in clean air. Duration
19、 of the on-off cycles shall be a joint decision between the testing agency and the sensor manufacturer with the goal of simulating operational cycles in its application. c. Sensor and/or system shall be subjected to 14 days of thermal cycling between the extreme temperature likely to occur during no
20、rmal use and which may result from ambient temperature variation, or the cycling of supply voltage. The ambient temperature shall be varied between the manufacturers declared Tmaxand Tminoperating temperatures to cause the temperature of the components to be cycled between their declared operating e
21、xtremes. The rate of ambient temperature change shall be approximately 2F/minute (1C/minute) and the temperature at Tmaxand Tminshall be maintained for at least 1 hour, or until the sample reaches ambient temperature, whichever is longer. Care shall be taken to avoid the occurrence of condensation d
22、uring this test. During the temperature cycling test the sensor and/or system shall be energized to 110 percent of rated voltage, except for at least one 1 minute and no longer than 30 minutes during each 24-hour period the sensor and/or system shall be deenergized. The deenergization is not to be s
23、ynchronized with the change in the ambient temperature. d. The sensor or systems sensor component(s) shall be subjected to ten cycles of flammable vapor exposure. The sensor or systems sensor component(s) shall be mounted in a typical test chamber specified in 2.2, Flammable Vapor Sensitivity. The m
24、anufacturer shall specify the concentration of flammable vapor exposure. If necessary, refer to the manufacturers response curve for the sensors response characteristics. The sensor or systems sensor component(s) shall be maintained at manufacturers specified concentration for a period of two hours
25、or until the sensors or systems signal does not change by 5 percent over a period of 15 minutes. The vapor concentration within test chamber shall then be evacuated with clean room air and the exposure repeated ten times.e. Manual reset sensors or systems sensor component(s) shall also be subjected
26、to ten cycles of flammable vapor exposures as defined in 2.2, Flammable Vapor Sensitivity, except at room temperature and humidity only. The sensor or systems sensor component(s) shall be reset after each exposure cycle.2.4 Environmental TestingThe sensor and system shall be capable of withstanding
27、unpowered storage at temperatures of -40F to 175F (-40C to 79.4C).3Method of TestOne sample shall be placed in a chamber and maintained at a temperature of -40F 5F (-40C 2.7C) for 24 hours, returned to room temperature for 1 hour, then in a chamber maintained at 175F 5F (79.4C 2.7C) for 24 hours.Aft
28、er the sample returns to room temperature, the sensor and system shall comply with 2.2, Flammable Vapor Sensitivity, at ambient temperature and humidity when completed. 2.5 VibrationA flammable vapor sensor and system shall not be adversely affected by exposure to vibration. The sensor and system sh
29、all be securely fixed to a vibration generator by its intended mounting means either directly or by means of a fixture. Care shall be taken on the test fixture to reduce and/or eliminate resonant frequencies above the test frequency range. The fixture shall enable the sensor and system to be vibrate
30、d in each of three perpendicular planes. Method of TestFrequency shall be varied by continuously sweeping over the specified range at a rate of one octave per minute +/- 10 percent. Frequency tolerance for the frequency shall be +/- 1 percent up to and including 50 hertz and +/- 2 percent above 50 h
31、ertz. Vibration amplitude tolerance in the observed direction shall be +/- 15 percent.The maximum acceleration (vibration) level shall be 5 g and the frequency range shall be 10 to 150 hertz. The applied motion shall be sinusoidal and result in the fixing points of the control moving in phase and in
32、 straight parallel lines. The motion shall attain maximum displacement amplitude of 0.014 inch (0.35 mm) as frequency is increased from 10 hertz until a crossover point at 60 hertz is reached which is where the specified maximum acceleration is attained. The maximum acceleration level shall then be
33、maintained as frequency is increased to the upper limit of the range. The maximum acceleration or displacement amplitude levels are to be maintained as frequency is reduced through the crossover point to 10 hertz.Vibration resonances shall be noted and the control shall be vibrated at those resonant
34、 frequencies for 10 minutes. If no resonant frequency is obtained, the control shall be tested for ten sweep cycles. For this test, a sweep cycle is a traverse of the specified frequency range from minimum to maximum and back to minimum frequency.Amplitude shall be the maximum displacement of sinuso
35、idal motion from a position of rest or one-half of the total table displacement.Resonance is the magnification of the applied vibration occurring on a part or assembly.Following vibration testing the sensor and system shall comply with 2.2, Flammable Vapor Sensitivity, at ambient temperature and hum
36、idity when completed.2.8 Accelerated Cummulative Chemical Exposure TestThe sensor or systems sensor component(s) under test shall be capable of meeting the requirements of section 2.2 after exposure to the chemical mixtures found in Table X, at ambient temperature and humidity when completed. The se
37、nsors shall be tested one to four weeks after exposures to the chemical mixtures.4The chemical exposure tests may be conducted individually and in consecutive order, or to reduce the overall testing time, in any simultaneous combination as mutually agreed to by the manufacturer and testing agency. C
38、oncentrations shall be maintained at a level well below the concentration for each gas that might be expected to cause a false alarm.2.13 Transient VoltageThe flammable vapor system and sensor shall be subjected to the electrical transient (see Part IV, Definitions) voltage tests specified in the fo
39、llowing Method of Test without evidence of unsafe failure.Method of TestThe tests outlined below shall be conducted at rated voltage with the system in a standby mode and after exposure to the tests specified in 2.2, Flammable Vapor Sensitivity. These tests shall be conducted on one representative s
40、ample of the system or sensor. A different set of samples may be used for the evaluation of each mode.If a component or network is incorporated whose sole function is that of suppressing external transient voltages, these tests shall be conducted with the component or network both functional and byp
41、assed.Evidence of an unsafe failure during or upon completion of any of the tests specified below shall constitute noncompliance.a. Line TransientsThis test shall be applied only to systems or sensors intended for connection to an alternating current electrical supply.A transient voltage generator h
42、aving an output impedance of 50 2.5 ohms shall be used for conduct of this test. The generator shall be connected to a non-inductive load of 50 2.5 ohms, and adjusted so that the peak voltage of the transient voltage pulse is 1200 50 volts, and the pulse shape is 2.5 microseconds maximum rise time f
43、rom 30 to 90 percent peak voltage and between 15 and 30 microseconds decay time to half peak voltage. After adjustment of the generator, the load shall be removed.The system or sensor under test shall then be connected to a power supply of rated voltage. The transient voltage pulse output of the gen
44、erator shall be applied to the primary power supply with the system or component operating in the mode(s) under test. The pulses shall be imposed without synchronization to the power sine wave at a repetition rate of 26 3 pulses per second. A total of 1,000 pulses shall be applied with a positive po
45、larity. This test shall then be repeated with the application of pulses having a negative polarity.b. Lightning TransientsThis test shall be applied only to systems or sensors intended for connection to an alternating current power supply.The transient shall have an energy level equivalent to 6 kilo
46、volts discharge from a 0.1 micro Farad capacitor through a 100-ohm resistor.The lightning transient shall be applied to the primary power supply 10 times with a positive polarity and 10 times with a negative polarity for each mode.5c. Static DischargeThis test shall be applied to all the flammable v
47、apor system and sensors regardless of the type of power supply.The test shall be conducted with the power supply connected as indicated in application and with the system or sensor (1) electrically grounded and (2) isolated from ground. The test shall then be repeated with the power supply disconnec
48、ted and with the system or sensor (1) electrically grounded and (2) isolated from ground.The static discharge transient shall consist of 20 kilovolts discharged from a 100 Pico Farad capacitance through a 100-ohm resistance.The static discharge transient shall be applied between any surface and term
49、inal, which could be contacted during normal servicing.If operable after completion of the transient voltage test, the sensor or system shall be capable of meeting the requirements of 2.2, Flammable Vapor Sensitivity, at ambient temperature and humidity.2.14 Effects Of Condensation2.14.2When required by 2.14.1, the flammable vapor sensor shall be subjected to the following test without evidence of unsafe failure.Method of TestThe same sample tested under 2.14.1 shall be placed in room air at room ambient temperature and humidity conditions for
