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Self-Propelled Sweepers Sweep-Ability Performance: Testing and Standards
SAE J1702-2022 establishes a consistent method for evaluating the sweep-ability performance of self-propelled sweepers. This standard is crucial for manufacturers, test engineers, and fleet operators seeking to compare sweeper capabilities under similar conditions. The standard outlines three distinct tests using sand, gravel, and various objects to comprehensively assess a sweeper’s ability to collect debris. This article provides an overview of the key aspects of the standard, including test preparation, execution, and scoring.
Overview of the Test Method
The standard defines three separate tests, each using consistent materials placed in three zones (X, Y, Z) on a level paved test site. The sweeper must make three runs per test, collecting material at a specific speed or within a timed period. The table below summarizes each test.
| Test | Material | Total Quantity | Scoring |
|---|---|---|---|
| 1 – Sand Spread | Builders sharp sand (0.5 mm avg grain, density ~1600 kg/m³) | 150 kg (50 kg per zone) | Percentage of sand collected |
| 2 – Gravel Spread | Granite road stone chips (12 mm sieve 100% pass, density ~1800 kg/m³) | 150 kg (50 kg per zone) | Percentage of gravel collected |
| 3 – Object Removal | Assorted objects (e.g., exhaust pipe, stick, plastic bag, carton, muffler, cobble stone, beverage can, paper sheet, rope, wooden baton, bolt, nut, nail, washer, pin) | 50 items across zones X, Y, Z | Score based on assigned ratings; maximum total 100 or 100% |
The test site pattern includes a guideline along which the sweeper’s brooms are directed. Zone sizes and material quantities may be adjusted if the sweeper lacks capacity, but any variations must be recorded in the test report.
Key Technical Requirements
To ensure valid and repeatable results, the standard specifies strict conditions for the sweeper, weather, and test site.
- Sweeper Condition: The sweeper must be set to normal operational settings per the manufacturer, with brooms and curtains in like-new condition. If variable duties exist, the sweeper is operated at its maximum-duty cycle. Dust suppression systems, if provided, must be active.
- Weather Conditions: Tests must be conducted in dry conditions with wind speed less than 20 km/h to prevent displacement of test materials.
- Test Site: A level paved area with a gradient not exceeding ±3%. The material placement zones and guide path must be clearly defined as per Figure 1 of the standard.
- Travel Speed: The sweeper is driven at a predetermined speed or timed from start to finish. For speed-related tests, sweeping mechanisms are disabled at the finish line; for time-based tests, the shutdown time is recorded within the total test time.
🛠️ Engineering Insight: The use of three different debris types—fine sand, coarse gravel, and assorted objects—provides a comprehensive evaluation of a sweeper’s sweeping and conveyance mechanisms. The object test includes items of varying sizes, weights, and compositions (e.g., steel, aluminum, paper, rope), which challenges both mechanical and pneumatic systems. This design allows engineers to identify specific strengths and weaknesses in debris collection, such as the ability to handle large, irregular objects versus small, dense fasteners.
Scoring and Reporting Results
For Tests 1 and 2, performance is measured by the percentage of material collected. For Test 3 (Object Removal), each object carries a predetermined score rating (see Table 3 in the standard). The total score rating sums to 100 (or 100%). Objects that are not swept (either beyond the sweeper’s capability, deflected, or carried beyond the test course) are recorded as not swept and reduce the score accordingly.
⚠️ Common Mistake: Conducting tests with wind speeds exceeding 20 km/h can lead to inaccurate results, as lightweight objects may be displaced or blown away. Always verify weather conditions before testing and include any deviations in the report.
The test report must include the sweeper settings, any deviations from the standard material quantities or zones, weather conditions (including water content if wet sand is used), and the final scores. A suggested results record sheet is provided in the standard (Figure 2). The report should also state whether dust suppression systems were used.
Frequently Asked Questions
Q: What are the acceptable weather conditions for testing?
A: The test must be conducted in dry conditions with wind speed less than 20 km/h. If wind disturbs the test materials, the results may be invalid.
Q: How should the sweeper be prepared before testing?
A: The sweeper should be set to its normal operational settings per the manufacturer. Brooms and containment curtains must be in like-new condition, and the sweeper should be operated at its maximum-duty cycle if variable settings exist. Dust suppression systems, if fitted, must be active.
Q: What happens if the sweeper cannot pick up certain objects?
A: Objects that are beyond the sweeper’s capability may be removed from the test course but must be recorded as “not swept” in the test report. Any material that is deflected or carried beyond the test course is also considered not swept.
Q: How is travel speed controlled during the test?
A: The sweeper must be driven at a predetermined speed or timed from start to finish. For speed-related tests, sweeping mechanisms are disabled at the finish line. For time-based tests, the time taken to disable the mechanisms is included in the total test time.
