GB/T 24966-2023Grating vehicle detector (English PDF)

5.1 Structure

5.1.1 The product structure shall be simple, firm, and easy to install and adjust.

5.1.2 The installed connectors shall be free from defects such as obvious deformation and irregularity.

5.1.3 The communication interface and external connection shall be easy to install and maintain, and waterproof and dustproof measures shall be taken.

5.2 Appearance quality

5.2.1 The outer shell of the grating vehicle detector shall not have pits, scratches, deformations or cracks; the coating shall be smooth and uniform, with consistent color, and shall not have defects such as blistering and cracking.

5.2.2 The nameplates, marks, texts, etc. on the body of the grating vehicle detector shall be clear, firm, straight and not easy to fall off.

5.3 Functionality

5.3.1 The grating vehicle detector shall be capable of detecting one or more of the following, including the vehicle separation, vehicle height, vehicle width, axle, tire type, truck model and vehicle flow.

5.3.2 Type B grating vehicle detectors shall have an electric heating function to effectively prevent condensation and frost.

5.3.3 The grating vehicle detector shall have the function of automatically detecting the working status and fault detection, output alarm information when a fault occurs, and the system shall automatically return to normal working status after the fault is eliminated.

5.3.4 The data collected by the grating vehicle detector shall be able to be read in real time by a portable terminal, and other maintenance operations and local management shall be possible.

5.3.5 The communication interface of the grating vehicle detector shall use RS232, RS485, RS422 serial ports or RJ-45 Ethernet interface.

5.3.6 The grating vehicle detector may have a network management function.

5.4 Vehicle detection performance

5.4.1 The relative error of vehicle separation detection shall not exceed 0.1%.

5.4.2 The measurement error of vehicle height detection shall not exceed 100 mm.

5.4.3 The measurement error of vehicle width detection shall not exceed 100 mm.

5.4.4 The relative error of axle detection shall not exceed 0.1%.

5.4.5 The relative error of tire type detection shall not exceed 2%.

5.4.6 The relative error of truck model detection shall not exceed 1%.

5.4.7 The relative error of vehicle flow detection shall not exceed 0.1%.

5.4.8 The minimum resolution dimension of the vehicle separation detection type shall not exceed 50 mm.

5.4.9 The maximum effective detection distance between the transmitter and the receiver shall not be less than 8 m.

5.4.10 The separation detection response time shall not exceed 50 ms.

5.5 Electrical safety performance

5.5.1 AC power supply type grating vehicle detector

5.5.1.1 Power adaptability

The product shall work reliably under the following input voltage conditions.

-- Voltage. AC 220 × (1±15%) V;

-- Frequency. 50 × (1±4%) Hz.

5.5.1.2 Insulation resistance

The insulation resistance between the power terminal and the casing of the product shall be no less than 100 Mohm.

5.5.1.3 Dielectric strength

When applying a sinusoidal AC voltage of 50 Hz and effective value of 1500 V between the power terminal and the casing of the product for 1 min, there shall be no spark, flashover or breakdown.

5.5.1.4 Contact resistance

The product shall be equipped with a safety protection grounding terminal. The […]

5.6.5 Vibration resistance

In the power-on state, after scanning cycle vibration in the vibration frequency range of 2 Hz~150 Hz, the product shall function normally, the structure shall not be affected, and there shall be no loose parts.

5.6.6 Salt spray corrosion resistance

The product's outer shell anti-corrosion layer, supporting base plate and aviation joints shall have no obvious rust. Metal components shall have no red rust spots, and the anti-reflective coating material shall not fall off.

5.6.7 Weather resistance

After artificial accelerated aging, the product's shell anti-corrosion layer, light-emitting components and their supporting base plate shall show no obvious signs of aging.

5.6.8 Protection level

The product shall be rainproof and dustproof, and the protection level of the housing and control box shall not be lower than IP65 specified in GB/T 4208-2017.

5.7 Electromagnetic compatibility

5.7.1 Electrical fast transient burst immunity

Under normal working conditions, the power port, signal and control port of the product and the ground wire of the shell shall have the performance of resisting an electrical fast transient/burst. After being interfered with by an electrical fast transient/burst, the various actions, functions and operating logic of the product shall be normal.

5.7.2 Electrostatic discharge immunity

Under normal working conditions, the contact points, surfaces and maintenance points of the product shall have immunity to electrostatic discharge. After electrostatic discharge occurs, the various actions, functions and operating logic of the product shall be normal.

5.7.3 Radiated electromagnetic field immunity

Under normal working conditions, the product shall have immunity to radiated electromagnetic fields. After being exposed to a radiated electromagnetic field, the various actions, functions and operating logic of the product shall be normal.

5.8 Reliability

The mean time between failures (MTBF) of the product shall be no less than 30,000 hours.

6.1 Test conditions

The test is usually carried out under standard atmospheric conditions.

a) Ambient temperature. 15 °C~35 °C;

b) Relative humidity. 25%~75%;

c) Atmospheric pressure. 86 kPa~106 kPa.

6.2 Structure

Inspect the structure and mounting connections of the detector by visual inspection and hand feel.

6.3 Appearance quality

Check the appearance quality of the detector by visual inspection and hand feel.

6.4 Functionality

6.4.1 Install the product as required, power it on, and after the system enters the normal working state, the vehicle is driven at a speed not exceeding 20 km/h, and the corresponding functions are verified according to the type of grating vehicle detector.

6.4.2 Simulate condensation and frosting in an environmental test chamber or other specific environment. After turning on the heating function, observe whether the condensation and frosting disappear.

6.4.3 According to the type of equipment failure, manually simulate various types of failures to observe whether there is any fault alarm information output. After canceling the simulated failure, observe whether the system automatically returns to the normal working state.

6.4.4 Use a portable terminal to read the data collected by the grating vehicle detector in real time and perform other maintenance operations to verify whether the function is normal.

6.4.5 When using RS232, RS485, and RS422 serial ports or RJ-45 Ethernet interfaces to transmit data, verify whether the data can be transmitted accurately and reliably.

6.4.6 Set the IP address for the device and verify whether network management such as login, setting and collection can be performed.

6.5.6 Relative error of truck model detection

enters the normal working state, the vehicle is driven at a speed not exceeding 20 km/h for 1000 consecutive tests. The relative error of vehicle model detection is calculated using the detection results of the grating vehicle detector and the results of human eye recognition. The vehicle model test samples do not include specially modified vehicles such as passenger-to-cargo conversions.

6.5.7 Relative error of vehicle flow detection

Connect and install the product as required, power it on, and run it. After the system enters the normal working state, the vehicle is driven at a speed not exceeding 20 km/h, and no less than 1000 vehicles are continuously detected. The relative error of vehicle flow detection is calculated using the detection results of the grating vehicle detector and the counting results of the counter or other counting methods.

6.5.8 Minimum resolution size

Use a spherical opaque standard part with a diameter of 50 mm, select any point at each of the three height areas of high, medium and low that can be identified by the grating vehicle detector, and let the standard part pass through the identification area in any direction at these points.

6.5.9 Maximum working distance

When the working distance between the transmitter and the receiver or the detection vehicle is set to 8 m, the system can still work normally.

6.5.10 Separation detection response time

Assemble the system and place it in a normal outdoor environment. Use an oscilloscope to read the trigger and recognition time. Perform the test continuously for not less than 100 times and calculate the average value (T) as the test result.

6.6 Electrical safety performance

6.6.1 AC power supply type

6.6.1.1 Power adaptability

6.6.1.1.1 Use an autotransformer or adjustable AC power supply with a power frequency of 50 Hz, and adjust the test voltage to 180 V, 200 V, 220 V, 240 V, 255 V, 230 V, 210 V, and 180 V in sequence. After each voltage is reached and stabilized, turn on and off the power switch of the test product to check whether the logic and function are normal.

6.6.1.1.2 Use variable frequency AC power supply with a constant voltage of 220 V, and adjust the test frequency to 48 Hz, 49 Hz, 50 Hz, 51 Hz, and 52 Hz in sequence.

After each frequency is reached and stabilized, turn on and off the power switch of the test product to check whether the logic and function are normal.

6.6.1.2 Insulation resistance

Use a 1.0 accuracy class, 500 V megohmmeter to measure between the power supply terminal and the casing.

6.6.1.3 Dielectric strength

Use a withstand voltage tester with an accuracy class of 2.0 to test it between the wiring terminals and the casing.

6.6.1.4 Grounding resistance

Use an ohmmeter with an accuracy class of 0.5 and a resolution of 0.01 ohm to measure it between the metal part on the top of the casing and the safety protection grounding terminal.

6.6.2 DC power supply type

6.6.2.1 DC input voltage

Use a DC power supply and adjust the test voltage to 90% and 110% of the rated input voltage respectively. After each voltage stabilizes, turn on and off the power switch of the test product respectively to check whether it works normally.

6.6.2.2 Lightning protection and overvoltage protection

Verify by inspection and, if necessary, by simulating overload or short-circuit fault conditions.

6.7 Environmental adaptability

6.7.1 Low-temperature resistance

Carry out the test for 8 hours in accordance with the provisions of GB/T 2423.1.

6.7.2 High-temperature resistance

Carry out the test for 8 hours in accordance with the provisions of GB/T 2423.2.

6.7.3 Damp heat resistance

Carry out the test for 48 hours in accordance with the provisions of GB/T 2423.3.

6.7.4 Temperature alternation resistance

7.2 Batch grouping

Products are inspected in batches, and products produced from the same materials, same processes and same production equipment are considered to be one batch.

7.3 Sampling

7.3.1 The sample for type inspection shall be a complete product randomly selected.

7.3.2 For products with a batch size of no more than 3 units, the factory inspection shall be conducted by the quality inspection department of the product manufacturer on a unit-by-unit basis. For products with a batch size of more than 3 units, the samples for factory inspection shall be randomly selected from the end of the production line, not less than 30% of the samples, but not less than 3 units.

7.4 Judgment rules

7.4.1 During the type inspection, if the electrical safety performance fails to meet the standards, the type inspection result is considered to be FAIL. If other items fail to meet the standards, double numbers of samples shall be taken from the same batch of products to be inspected for the failed items. If the samples still fail to meet the standards, the type inspection result is considered to be FAIL.

7.4.2 When samples are inspected one by one before leaving the factory, certificates of conformity are issued after they pass the inspection, and then they can leave the factory.

When no less than 30% of the samples are taken for factory inspection, if all the samples are qualified, the entire inspection batch is qualified, certificates of conformity are issued and the products are allowed to leave the factory; if one unit fails, the entire batch shall be inspected one by one to eliminate the unqualified products.

7.4.3 During the factory inspection, rejected defective products are allowed to be repaired. After the repair, the defective items shall be re-inspected, but the number of repairs shall not exceed 2 times.

8.1 Marking

8.1.1 Product marking

Product marks can be in the form of nameplates or direct spraying, printing, etc. The marking shall be clear, easy to identify and not easy to fade or fall off due to changes in the natural environment. The following shall be indicated on the product mark.

a) Name, address and trademark of the manufacturer; […]