Daily maintenance and false alarm handling of tunnel belt metal detector

Abstract: What should I do if the online detection equipment such as the metal detector fails? Naturally, the shutdown of the production line will bring huge losses to manufacturers in many ways. In order to obtain the best detection results for the metal detector, proper daily maintenance and simple troubleshooting are obviously essential.

Most manufacturers and processors use metal detectors as one of the core links of effective quality control in the production process. An effective metal detection mechanism can avoid product quality problems and product recalls, and help protect customers' product quality and brand image. However, in an efficient production process, what should I do if the online inspection equipment such as the metal detector fails? Naturally, the shutdown of the production line will bring huge losses to manufacturers in many ways. In order to obtain the best detection results for the metal detector, proper daily maintenance and simple troubleshooting are obviously essential.

Daily maintenance of metal detector

The detection principle of the metal detector is electromagnetic induction. When the metal passes through the detection head, the equilibrium state is broken and the output voltage is generated at the same time. If the signal value is greater than the set value, the metal detector will judge that there is metal passing and give an alarm. In daily maintenance, special attention should be paid to the electrical and mechanical parts of the metal detector.

■Electrical part

It is very important to check the quality of the power supply. Good power supply quality can prolong the life of electrical components and reduce the interference of clutter in the power supply on the detection head. The power supply voltage should be within ±15% of the rated voltage. If it is mixed with the on-site industrial power, it is recommended to install a stabilized power supply, power filter or UPS to ensure the quality of the power supply voltage and waveform. The electrical panel in the metal detector should be kept in a well-sealed state to prevent dust and water from entering the panel, causing unnecessary damage to electrical components.

■Mechanical part

Metal detectors provide tailor-made solutions according to different product characteristics and customer requirements. Different customers will choose different types of metal detectors. Due to the different detection methods, the mechanical structure of the product is also different, and the specific maintenance parts will also change accordingly. Here we enumerate three more commonly used types of metal detectors and tell you how to maintain the mechanical parts.

1. Window-type metal detectors This series of metal detectors are suitable for all kinds of products conveyed by conveyor belts, including bulk materials, processed products and packaged products, and are widely used in various industries.

■When testing the detection effect, the test sample should be passed through the center of the window.

■Pay attention to whether the conveyor belt is off-track. If it is off-track, adjust it in time to avoid damage to the conveyor belt.

■Clean the conveyor belt regularly.

■Avoid welding or cutting metal near the conveyor belt to prevent metal chips from adhering to the conveyor belt.

2. Gravity Falling Metal Detector This series of metal detectors can be used for various bulk materials, including refined bulk materials, raw materials, and even irregular objects with larger particles.

■When testing the detection effect, the test sample should be dropped from the center of the tube.

■The compressed air of the rejector is set at about 4 bar to avoid excessive wear of the rejector.

■After the ejector is disassembled and cleaned, it should be noted that all parts must be installed back to their original positions.

■Check whether the seal ring of the ejector is aged or broken to prevent powder leakage.

False alarm handling of metal detector

During the use of the metal detector, false alarms may occur due to location changes, environmental interference, incorrect product settings, etc. Some of the false alarms can be eliminated and avoided through simple operations, effectively reducing the downtime of the production line and improving production efficiency.

Ways to eliminate false alarms

■Whether the sensitivity is set too high. Sensitivity can also cause unnecessary false alarms while improving the detection accuracy, so effective detection can only be carried out by selecting the appropriate sensitivity.

■Whether the product has a "product effect". Products such as cheese, fresh meat, jam or pickled products have their own "product effect", which will produce interference signals that affect the detection effect. For similar products, methods such as reducing sensitivity and changing operating frequency can be adopted.

■Whether the conveyor belt always stops at the same position when alarming. Containing foreign objects on the conveyor belt can also cause false alarms. You can choose to clean or replace the conveyor belt. We strongly recommend customers not to place metal in the "metal-free zone" range.

■Is there any interference around the metal detector. Interference often has an adverse effect on the performance of the metal detector. Please adjust the possible interference sources around when encountering similar problems and observe whether the interference is weakened or disappeared in order to obtain the best performance. It is worth noting that when the metal detector is operated with high sensitivity, the effect of these factors becomes more and more obvious, and the number of products that are mistakenly rejected will increase significantly. It is recommended to power off the surrounding equipment first.

If you can't solve the fault by simple operation, you can contact the professional service personnel of Fengling Automation. In order to allow your testing equipment to be repaired in time, I hope you can cooperate with us:

■Record the serial number of the metal detector.

■Describe the fault information in detail when contacting. If it is a simple fault, you can reset it according to the operation steps of the service personnel on the phone to eliminate the fault.

■Please do not disassemble the metal detector at will to avoid accidental damage to the product.

Fengling automated metal detectors provide comprehensive after-sales service. Among them, the metal detector evaluation certificate PVC can help you obtain:

■Check the working status of equipment on site

■Discover equipment problems in time and implement preventive maintenance

■Keep inspection records for future tracking

■The inspection cycle can be flexibly adjusted according to the usage