GB/T 47438.3-2026Special requirements for fire alarm and evacuation in hazardous chemicals workplaces - Part 3: Combustible gas detection and alarm systems (English PDF)

4.2.1 Linkage Control Method

4.2.1.1 When the control requirements cannot be met due to the length of wires and cables between the controller with linkage control function and the controlled equipment, the following measures shall be taken. Use the following control method.

a) Controlled fire-fighting equipment is powered by a fire-fighting power supply near the installation site; other controlled equipment is powered by a power supply near the installation site. The controller should monitor the power status of the controlled equipment;

b) Control signals are transmitted using electro-optical conversion devices, optical fibers, and opto-electrical conversion devices to control the controlled equipment.

4.2.1.2 When a combustible gas alarm controller with linkage control function receives a combustible gas alarm signal and initiates linkage control, the alarm linkage... The motion time should not exceed 2 seconds.

4.2.2 Online component replacement function The combustible gas alarm controller should have the function of replacing combustible gas detectors without power interruption. When replacing parts, non-replacing parts should not be affected. Normal operation.

4.3.1 Basic Functional Requirements

4.3.1.1 The combustible gas alarm controller shall have two alarm functions. low limit and high limit. The low limit and high limit alarms shall have alarm sound and light signals.

4.3.1.2 When a combustible gas alarm signal is input, the controller shall issue a combustible gas alarm sound and light signal within 3 seconds.

4.3.1.3 For combustible gas alarm controllers using bus communication, if any point in the circuit is short-circuited or open-circuited, the combustible gas alarm controller should... Within 60 seconds, it emits an audible and visual fault signal that is clearly distinct from the alarm signal, and the combustible gas alarm controller, combustible gas detector, and connected components... The connected alarm trigger device should communicate normally.

4.3.1.4 The combustible gas alarm controller should have a concentration output function, sending concentration information to the graphic display device in the fire control room, etc. equipment.

4.3.1.5 The operating data storage unit of the combustible gas alarm controller shall adopt an independent, detachable structure with a metal casing, and the casing protection level shall be [not specified]. The IP code should not be lower than the requirements of IP54 in GB/T 4208-2017, and the function should meet the requirements of Appendix A.

4.3.2 Redundancy Design Requirements

4.3.2.1 General Requirements The combustible gas alarm controller should adopt a redundant design, with each unit implementing the main control function, power control function, and communication function having at least One spare unit. The appearance, circuit board, components, and program of the main unit and the spare unit should be identical. The main unit and the spare unit should have different... The function of disconnecting the power supply for replacement.

4.4 Basic Performance of Combustible Gas Detectors

4.4.1 Combustible gas detectors should have low-limit and high-limit alarm functions.

4.4.2 If the low-limit alarm setting is adjustable, the alarm setting should have a manual query function.

4.4.3 When the concentration of combustible gas in the monitored area reaches the alarm condition, the combustible gas detector should issue an audible and visual alarm within 2 seconds. The low-limit and high-limit audible and visual alarm signals should be clearly distinguishable.

4.4.4 Under rated operating voltage conditions, the peak sound pressure level (A-weighted) of the detector's alarm sound signal at a distance of 1m directly in front of it should not be less than [a certain value]. It is between 75dB and no greater than 115dB.

4.5 Gas concentration display function Both the combustible gas alarm controller and the combustible gas detector should have a gas concentration display function, and the absolute value of the difference between the displayed values should be No more than 1% of full scale.

4.6 Enclosure Protection Rating The enclosure protection rating (IP code) of outdoor combustible gas alarm controllers and combustible gas detectors should not be lower than GB/T 4208- IP65 requirements in.2017.

4.7 Climate and Environmental Tolerance The combustible gas detector shall withstand all tests under the climatic conditions specified in Table 1, and shall meet the following requirements during and after the tests. Require.

4.8 Resistance to fluorescent UV lamp aging Outdoor combustible gas detectors should withstand the fluorescent ultraviolet lamp aging (operation) test specified in Table

2.During the test, combustible gas... The combustible gas detector should be kept in normal monitoring condition; after the test, the combustible gas detector should not show any damage to the coating or corrosion. The difference between the alarm action value and the alarm setting value should meet the following requirements.

a) For combustible gas detectors with a measurement range of 3% LEL to 100% LEL, the alarm activation value should not be less than 5% LEL, and should be consistent with the alarm... The absolute value of the difference between the alarm setpoints should not exceed 7% LEL;

b) For combustible gas detectors with a measurement range below 3% LEL, the absolute value of the difference between the alarm action value and the alarm set value should not exceed 3%. The larger of 7% of the range and 120 × 10^-6 (volume fraction) is detected. This is the alarm value for a combustible gas detector that detects carbon monoxide. The action value should not be less than 50 × 10^-6 (volume fraction), and the absolute value of the difference between it and the alarm setting value should not be greater than 120 × 10^-6 (volume fraction). (Points).

4.9 Electromagnetic compatibility performance The combustible gas alarm controller and combustible gas detector shall withstand all tests under the electromagnetic interference conditions specified in Table 3, during the test period. The following requirements must be met during and after the test.

a) During the test, the combustible gas alarm controller and combustible gas detector should be kept in normal monitoring status.

b) After the test, the performance of the combustible gas alarm controller should meet the requirements of 4.3.1.2, and the alarm action value of the combustible gas detector should meet the following requirements. Require. 1) For combustible gas detectors with a measurement range of 3% LEL to 100% LEL, the alarm activation value should not be less than 5% LEL, and The absolute value of the difference between the alarm setting value and the alarm setting value should not exceed 5%LEL. 2) For combustible gas detectors with a measurement range below 3% LEL, the absolute value of the difference between the alarm activation value and the alarm setting value. It should not exceed the larger of 5% of the range and 80 × 10^-6 (volume fraction). Combustible gas detection for carbon monoxide. The alarm action value of the device should not be less than 50 × 10^-6 (volume fraction), and the absolute value of the difference between it and the alarm setting value should not be greater than [missing value]. At 80×10^-6 (volume fraction).

4.10 Resistance to poisoning

4.10.1 Except for detectors that detect toxic gases, combustible gas detectors should be used in environments with combustible gas concentrations of 1% LEL and nitrogen dioxide gas. The detector should not issue a combustible gas alarm during operation in a mixed gas environment with a concentration of (10±3)×10^-6 (volume fraction) for 40 minutes. Signal or fault signal.

4.10.2 After environmental interference, allow the detector to operate in normal monitoring mode for 20 minutes, then measure its alarm activation value. The detector's alarm activation value... The difference between the value and the alarm setting value should meet the following requirements.

a) For detectors with a measurement range of 3% LEL to 100% LEL, the alarm activation value should not be less than 5% LEL, and should be consistent with the alarm setting value. The absolute value of the difference should not exceed 10% LEL;

b) For detectors with a measurement range below 3% LEL, the absolute value of the difference between the alarm action value and the alarm set value should not exceed [a certain value]. The larger of 10% range and 160×10^-6 (volume fraction).

5.1 General Requirements

5.1.1 Atmospheric conditions for the experiment Unless otherwise specified in the relevant provisions, all tests shall be conducted under the following atmospheric conditions.

---Temperature. 15°C~35°C;

---Relative humidity. 25%~75%;

---Atmospheric pressure. 86kPa~106kPa.

5.1.2 Normal monitoring status of the experiment If the test method requires the specimen to be under normal monitoring conditions, the specimen should be connected to the load and/or control and indicating equipment provided by the manufacturer. Connect and maintain normal operating conditions; unless otherwise specified in the relevant clauses, ensure that its operating voltage is the rated operating voltage, and conduct tests. Maintain a stable operating voltage during this period.

5.1.3 Tolerance Unless otherwise specified in the relevant clauses, the tolerance for all test data is ±5%; deviations in environmental condition parameters shall comply with GB/T 16838. Require.

5.1.4 Sample The number of test samples should meet the following requirements and be numbered before the test.

a) One combustible gas alarm controller;

b) There are 10 combustible gas detectors.

5.1.5 Test Procedure The test procedures for the combustible gas detection and alarm system are shown in Tables 4 and 5.

5.2 Test of Linkage Control Mode

5.2.1 Check the signal transmission between the sample with linkage control function and the controlled equipment in accordance with the requirements of 4.2.1.1.

5.2.2 Cause the gas detector to issue an alarm signal that satisfies the linkage control logic, and simultaneously start timing to record the data with linkage control function. The time when the sample sends out the linkage control signal.

5.3 Component Online Replacement Function Test

5.3.1 With the sample powered on, disconnect any combustible gas detector connected to it, and inspect the sample according to the requirements of GB 16808. It has fault alarm functions and alarm functions for non-faulty parts.

5.3.2 Reconnect the disassembled combustible gas detector, reset the sample, and bring it to normal monitoring status. This should be done in accordance with GB 16808. Please provide an alarm function for inspecting the test samples.

5.4 Basic Function Test of Combustible Gas Alarm Controller

5.4.1 Check and record the low and high limit alarm status of the sample.

5.4.2 Place the sample in normal monitoring mode, cause the combustible gas detector to issue a combustible gas alarm signal and start timing, and measure the sample alarm. Police response time.

5.4.3 For samples using bus communication, short-circuit and open-circuit any point in the circuit respectively, and observe and record the sample's condition. This allows the combustible gas detector to... The detector sends out a combustible gas alarm signal, and the condition of the sample is observed and recorded.

5.4.4 Connect the sample to the graphic display device in the fire control room, observe and record the sample concentration output.

5.4.5 Check and record the status of the sample operation data storage unit, and conduct the test in accordance with the requirements of Appendix A.

5.5 Redundancy Function Test

5.5.1 Inspect the appearance, circuit board, component settings, and program version number of the main unit and backup unit of the sample.

5.5.2 Connect combustible gas detectors to at least two locations or detection zones within the same alarm circuit of the sample. For samples with multiple circuits, at least Connect a combustible gas detector to another circuit as described above. Other circuits can be connected to equivalent loads. Turn on the power to bring the sample into a suitable environment. It is under normal monitoring status and connected to the graphic display device in the fire control room to maintain normal communication.

5.5.3 Operate the sample to cause a malfunction in the main unit, check the standby unit switching status, restore the main unit to normal function, and check the main unit... The recovery status of the sample is recorded, and the establishment time of the sample's state information is recorded.

5.5.4 Operate the sample to cause malfunctions in both the main unit and the backup unit, and check the sample's status indication and fault indication. The situation was assessed, and the sound pressure level of the audio equipment was measured.

5.6 Operational Function Test under Display Device Fault Conditions Operate the sample to cause a malfunction in its display device and control circuit, and check the sample's function according to the requirements of 4.3.3.

5.7 Basic Performance Test of Combustible Gas Detector

5.7.1 Check the low and high limit alarm functions of the sample.

5.7.2 For samples with adjustable alarm settings, check whether the alarm settings can be manually queried.

5.7.3 When the concentration of combustible gas in the monitored area reaches the alarm condition, observe and record the alarm time and the emitted combustible gas from the sample. The status of alarm sounds and light signals.

5.7.4 Measure and record the sound pressure level of the alarm sound signal of the combustible gas of the sample.

5.8 Gas Concentration Display Function Test To put the system into normal monitoring mode, the concentration of combustible gas in the monitored area was set to 20%, 30%, and 40% of full scale, respectively. 50% and 60%. During the test, the test gas at each concentration should be maintained for at least 1 minute, and the displayed values of the samples should be recorded separately.

5.9 Enclosure Protection Rating Test The enclosure protection rating of the specimen shall be checked and recorded in accordance with the method specified in GB/T 4208-2017.

5.10.1 Test Procedure

5.10.1.1 Place the sample in the damp heat test chamber and bring it under normal monitoring conditions.

5.10.1.2 The sample shall be subjected to alternating humidity at a high temperature of (40±2)°C for two cycles, according to the test method specified in GB/T 16838. Thermal (operational) test. During the test, observe and record the condition of the sample.

5.10.1.3 Remove the sample from the test chamber and place it under normal atmospheric conditions for at least 1 hour. The test should be performed according to GB 15322.1-2026. Quantitative sample alarm action value.

5.10.2 Test Equipment The testing equipment shall meet the requirements of B.1 in GB/T 16838 and GB 15322.1-2026.

5.11.1 Test Procedure

5.11.1.1 Place the sample under normal atmospheric conditions for at least 1 hour. Install the test part of the sample inside the test chamber. During the test, the sample should not be... power ups.

5.11.1.2 Following the test method for sulfur dioxide (SO2) corrosion (durability) testing in GB/T 16838, the tested portion of the sample was subjected to sulfur dioxide corrosion. The sulfur content was (25±5)×10-6 (volume fraction), the temperature was 25°C±2°C, the relative humidity was 75%±5%, and the duration was 21 days. Corrosion durability test.

5.11.1.3 Remove the test part of the sample and immediately place it in a test chamber at a temperature of 25°C±2°C and a relative humidity of less than 50% to dry. 16h. Then, after recovering under normal atmospheric conditions for 1h to 2h, the sample is visually inspected and the results are recorded.

5.11.1.4 Measure the alarm action value of the sample in accordance with the requirements of GB 15322.1-2026.

5.11.2 Test Equipment The testing equipment shall meet the requirements of B.1 in GB/T 16838 and GB 15322.1-2026.

5.12.1 Test Procedure

5.12.1.1 Place the sample in the test chamber and ensure that the sample is not energized.

5.12.1.2 The following tests shall be performed on the specimens in accordance with the test methods specified in GB/T 2423.22.

a) Cool to (-40±2)°C at a cooling rate not exceeding 1°C/min, for a duration of 2h;

b) Increase the temperature to (70±2)°C at a heating rate not exceeding 1°C/min, and maintain the temperature for 2 hours;

5.12.1.3 Remove the sample from the test chamber and place it under normal atmospheric conditions for at least 1 hour. Measure according to GB 15322.1-2026. Sample alarm action value.

5.12.2 Test Equipment The testing equipment shall meet the requirements of B.1 in GB/T 2423.22 and GB 15322.1-2026.

5.13.1 Test Procedure

5.13.1.1 Install the sample in the ultraviolet aging test chamber specified in Appendix C of GB/T 47438.1-2026, and connect the sample power supply. To ensure it is in normal working order.

5.13.1.2 Test the samples according to the fluorescent ultraviolet lamp aging conditions specified in Table 2.

5.13.1.3 During the test, observe and record the working status of the sample.

5.13.1.4 After the test, the alarm action value of the sample shall be measured in accordance with the requirements of GB 15322.1-2026.

5.13.2 Test Equipment The testing equipment shall meet the requirements of Appendix C of GB/T 47438.1-2026 and B.1 of GB 15322.1-2026.

5.14.1 Test Procedure

5.14.1.1 The test specimen shall be arranged in accordance with the provisions of GB/T 17626.3 to ensure that the specimen is under normal monitoring conditions.

5.14.1.2 The radio frequency electromagnetic field radiation interference shall be applied to the sample according to the test method specified in GB/T 17626.3, under the conditions shown in Table 3.

5.14.1.3 During the test, observe and record the working status of the sample.

5.14.1.4 After the test, check the alarm function of the combustible gas alarm controller. The combustible gas detector shall conform to the requirements of GB 15322.1-2026. Require the measurement of alarm action values.

5.14.2 Test Equipment The testing equipment shall meet the requirements of B.1 in GB/T 17626.3 and GB 15322.1-2026.

5.15.1 Test Procedure

5.15.1.1 The test specimen shall be arranged in accordance with the provisions of GB/T 17626.4 to ensure that the specimen is under normal monitoring conditions.

5.15.1.2 Electrical fast transient burst interference shall be applied to the specimen under the conditions shown in Table 3 according to the test method specified in GB/T 17626.4.

5.15.1.3 During the test, observe and record the working status of the sample.

5.15.1.4 After the test, check the alarm function of the combustible gas alarm controller. The combustible gas detector shall meet the requirements of GB 15322.1-2026. Measure alarm action values.

5.15.2 Test Equipment The testing equipment shall meet the requirements of B.1 in GB/T 17626.4 and GB 15322.1-2026.

5.16.1 Test Procedure

5.16.1.1 Arrange the test specimens according to the provisions of GB/T 17626.5 to ensure that the specimens are under normal monitoring conditions.

5.16.1.2 Apply surge (impact) interference to the specimen under the conditions shown in Table 3 according to the test method specified in GB/T 17626.5.

5.16.1.3 During the test, observe and record the working status of the sample.

5.16.1.4 After the test, check the alarm function of the combustible gas alarm controller. The combustible gas detector shall meet the requirements of GB 15322.1-2026. Measure alarm action values.

5.16.2 Test Equipment The testing equipment shall meet the requirements of B.1 in GB/T 17626.5 and GB 15322.1-2026.

5.17 Anti-poisoning performance test

5.17.1 Test Procedure With the sample under normal monitoring conditions, place a combustible gas detector in a environment with a combustible gas concentration of 1% LEL and nitrogen dioxide gas. The sample was subjected to a mixed gas environment with a concentration of (10±3)×10^-6 (volume fraction) for 40 min. After the conditional test, the sample was placed under normal monitoring. The alarm action value was measured for 20 minutes in accordance with the requirements of GB 15322.1-2026.

5.17.2 Test Equipment The testing equipment shall meet the requirements of B.1 in GB 15322.1-2026.

6.1 Factory Inspection

6.1.1 Factory inspection of combustible gas alarm controller products Before products leave the factory, enterprises should conduct the following tests on combustible gas alarm controllers.

a) Basic function test of the combustible gas alarm controller;

b) Redundancy function test;

c) Testing the operational functions of the display device under fault conditions;

d) Gas concentration display function test. Each controller shall undergo the above tests before leaving the factory (except for 5.4.5). Controllers shipped as components shall be compatible with relevant parts. The components are assembled into a complete machine and subjected to the above tests. If any one of the tests fails, the product is deemed unqualified.

6.1.2 Factory inspection of combustible gas detector products Before products leave the factory, companies should conduct the following tests on combustible gas detectors.

a) Basic performance test of combustible gas detector;

b) Gas concentration display function test. Each detector must undergo the above tests before leaving the factory. If any one of them fails, the product is deemed unqualified.

6.2 Type Testing

6.2.1 The type test items are the test items required in Table

4.Test samples are drawn from products that have passed the factory inspection.

6.2.2 Type testing shall be conducted under any of the following circumstances.

a) Trial production and type approval of new products or old products transferred to another factory for production;

b) Changes in the product's design, structure, materials, components, parts, manufacturing processes, or production conditions may affect product quality. Measure time;

c) When the technical requirements specified in the product standard change;

d) When production resumes after a shutdown of one year or more;

e) When the product quality supervision department requests type testing.

6.2.3 The test results shall be judged in accordance with the type test result judgment method specified in GB 12978.

7.1 Product Marking

7.1.1 Each device in the combustible gas detection and alarm system shall be clearly marked with an explosion-proof symbol (applicable to products with explosion-proof performance requirements). (Product), the standard number implemented by the product, the enclosure protection level and the environment in which it is used.

7.1.2 If uncommon symbols or abbreviations are used in the product marking information, they should be noted in the instruction manual.

7.2 Quality Inspection Marks Each device in the combustible gas detection and alarm system should have a quality inspection certificate.