OSENC Magnetic Separation
Make Gauss Measurements Repeatable
A credible magnetic field report identifies the product and test method well enough for another qualified person to repeat the measurement. At minimum it should state the instrument and calibration status, probe, units, position, orientation, contact or stand-off distance, measurement grid, temperature, tolerance, results and limitations. “Up to 12,000 Gauss” without these conditions is not an acceptance specification.
Field Values Change with Position
Magnetic flux density can change sharply over a few millimeters near a pole. Probe angle, pole-center location, tube wall, sleeve, gap, magnet temperature, nearby steel and product geometry can alter the reading. Reports must distinguish the strongest point from average, minimum, mapped or working-distance values.
Minimum Report Fields
| Category | Required information |
|---|---|
| Product | Part/model, drawing revision, serial/batch, dimensions, configuration and temperature condition |
| Instrument | Manufacturer/model, serial, probe type, range, units and calibration status |
| Method | Measurement surface, grid, reference datum, distance, probe orientation, pole location and nearby steel condition |
| Environment | Product and ambient temperature plus relevant setup conditions |
| Results | Individual readings, map or table, calculation method, tolerance and pass/fail |
| Traceability | Date, location, operator, reviewer, photographs and procedure revision |
Surface Field vs Working-Distance Field
Surface field is measured at or very near a product surface. Working-distance field is measured at a defined gap relevant to the application. A suspended magnet may require information at rated height, while a magnetic tube often uses a defined external-surface map. The two values should not be compared as if they represent the same performance.
Maximum, Minimum and Average
- Maximum: strongest measured point; useful only when the search method is defined.
- Minimum: lowest point within a specified acceptance grid.
- Average: requires a stated set of points and calculation.
- Uniformity: requires defined coverage and allowable variation.
Select the reporting statistic from the application. Reporting only the maximum can hide inactive ends, gaps between poles, or variation across width.
Common Reporting Errors
- No drawing or exact test position
- No probe orientation or distance
- Mixing Gauss and millitesla without clear conversion
- Using an unverified instrument or unknown range
- Comparing different tube walls, sleeves, gaps or temperatures
- Rounding readings until variation disappears
- Claiming capture efficiency from field readings alone
Example Acceptance Language
A specification should read like: measure at the listed grid points on the completed assembly, with the defined probe orientation and stand-off, at the stated temperature, using a calibrated instrument, and evaluate against the stated tolerance. The actual values, grid and tolerance must be approved for the real product; we do not invent them.
What Magnetic Field Reports Cannot Prove Alone
They do not directly prove pull force, lifting through burden, removal efficiency, capacity, product purity, liberation, flow behavior, belt tracking, mechanical integrity or long-term corrosion. Use process tests and mechanical inspections where those outcomes matter.
Review a Supplier Report
Check that the product, revision and configuration match your order; the report covers the working region rather than one favorable point; conditions match the specification; and failures or deviations are visible. Request raw readings instead of a certificate containing only “PASS.”
Report Fields So Another Inspector Can Repeat Them
| Decision rule | A useful report identifies the product, drawing, instrument, probe, orientation, grid, distance, temperature and result statistic for every value. |
|---|---|
| Inputs to confirm | Model or serial, magnetic state, surface condition, measurement coordinates, instrument and calibration, probe direction, zeroing, repetitions and tolerance. |
| Risk or limitation | A page of maximum values without locations cannot show coverage, inactive ends or variation and cannot be compared with a different probe orientation. |
| Buyer action | Attach a marked drawing or grid and preserve raw readings as well as the summarized acceptance result. |
What We Need to Configure This Project
Input set for What a Magnetic Field Test Report Should Include
- How we use your data: We compare your material, contamination risk, production target and line interface before we configure a proposal or rule out an unsuitable option.
- Material: name and composition; dry or wet; powder, granule, lump, fibre or slurry; minimum, maximum and typical particle distribution; moisture, stickiness, tendency to cake or bridge, abrasiveness, corrosiveness, bulk density, normal temperature and maximum temperature.
- Production and target: normal and peak throughput, continuous or batch feed, feed uniformity, contaminant or recovery target, magnetic response if known, typical and maximum target size, initial concentration, acceptable residual and whether product loss is permitted.
- Installation: belt width and speed, normal and maximum burden depth, magnet position and rated working distance, available suspension and maintenance space, support and lifting arrangement; cleaning method, permitted shutdown, contact-material, wear and corrosion requirements; indoor, outdoor, washdown, high-humidity, dusty or hazardous-area conditions.
- Supporting project files: drive voltage, frequency and phase where a self-cleaning unit is considered; control interface and any site air requirement; destination country; current drawings, site photographs, running video and a representative material/contaminant sample when testing is needed.
- What you receive next: We use the confirmed inputs to prepare a project-specific drawing and inspection plan. We do not treat performance as confirmed until the agreed design and any required representative test or site acceptance establish the result.
Project Support
Need documents, testing support or after-sales help?
Send your order reference, product details, application condition, requested document and supporting photos or videos so we can route the request correctly.
Frequently Asked Questions
Why is “Field Values Change with Position” important for this decision?
Magnetic flux density can change sharply over a few millimeters near a pole. Probe angle, pole-center location, tube wall, sleeve, gap, magnet temperature, nearby steel and product geometry can alter the reading.
Why is “Surface Field vs Working-Distance Field” important for this decision?
Surface field is measured at or very near a product surface. Working-distance field is measured at a defined gap relevant to the application.
Why is “Maximum, Minimum and Average” important for this decision?
Select the reporting statistic from the application. Reporting only the maximum can hide inactive ends, gaps between poles, or variation across width.
Ben — OSENC
Ben has more than 20 years of experience in the magnetic separation equipment industry and has worked with OSENC since 2019. He focuses on magnetic separators, tramp iron removal systems, metal recovery equipment, and custom magnetic separation solutions.
He helps customers clarify material type, particle size, moisture level, capacity, feeding method, target metal, and installation conditions, reducing wrong model selection, failed separation results, and unnecessary sample testing.