Choose the maker over the lowest price
Choosing the right manufacturer matters more than chasing the lowest price. Look for whether the maker is a drafting unit of the relevant industry standard, holds CE certification, offers customizable aperture sizes, and has a local sales and service network. Price depends on aperture size, detection accuracy, touchscreen, data logging and rejection functions. Define your product dimensions and detection requirements first, then request quotes — never select on price alone.
Standards and how accuracy is measured
On standards, the light-industry needle detector standard applies in China, while exported products usually must also meet EU CE requirements. Detection accuracy is expressed as the minimum ferrous sphere size the machine can detect; the smaller the number, the higher the sensitivity, but it depends on aperture size, product thickness, conveyor speed and environmental interference. Ask the supplier for test conditions and verify with standard test cards at different positions across the aperture.
Handle fault codes before opening up
When a fault code appears, don't rush to open the machine. Most codes correspond to issues you can check yourself, such as conveyor jams, blocked sensors, or power and wiring problems. Check the fault-code table in the manual first and follow its steps. If it persists, contact the manufacturer's technical support rather than disassembling the machine yourself, which can cause damage or void the warranty. Routine sensitivity calibration and cleaning prevent most faults in the first place.