Is the Explosion-Proof Rating of Shenghongchuang Mining Level Sensors Sufficient? Check Area Classification First, Then Certificates and the System

At locations such as underground mine sumps, drainage pump rooms, coal slurry ponds, and mineral processing reagent tanks, level data directly affects drainage interlocking, equipment protection, and on-site safety. When project managers ask whether the explosion-proof rating of Shenghongchuang mining level sensors is sufficient, they should not make a judgment based solely on the product name or verbal sales descriptions. Instead, they should verify the area of use, medium characteristics, installation method, power supply circuit, and the complete set of explosion-proof documentation together.

Xi'an Shenghongchuang Instruments & Meters Co., Ltd. provides level transmitters and supporting instruments for industrial measurement and control applications. Its manufacturing base, Shaanxi Qinkong Sensor Technology Co., Ltd., has production and testing capabilities for sensors, transmitters, and intelligent digital display control instruments. For mining projects, the key to whether a product can be used is not whether a “general-purpose level product is durable,” but whether the specific model meets mining explosion-proof requirements and project technical conditions.

The rational conclusion is that whether the explosion-proof rating is “sufficient” must be determined based on the nameplate of the intended procurement model, explosion-proof certificate, product manual, and regulatory requirements at the project location. Only when the model has obtained valid certification applicable to the target hazardous environment and is installed, wired, and maintained in accordance with the certification conditions does it provide a basis for evaluation for that application; without the corresponding documentation, ordinary industrial sensors should not be used as substitutes.

Why Mining Level Monitoring Has More Stringent Explosion-Proof Requirements

Underground Environments Are Not Simply “Wet Conditions”

Mining sites often involve humidity, vibration, dust, electromagnetic interference, and long-distance wiring at the same time. Underground coal mines may also involve explosive hazardous environments such as methane and coal dust. Sensor enclosures, cable entry devices, terminal chambers, and power supply methods can all become weak links in the safety chain.

Level sensors are generally installed near sumps, liquid pools, or storage tanks. The probe may remain submerged for extended periods, while cables may be laid along mine roadways for dozens or even hundreds of meters. Even if the measuring end itself operates reliably, insufficient junction box sealing, cable damage, or improper shield grounding may cause signal drift, equipment malfunction, or failure of explosion-proof conditions.

Therefore, projects should separately verify “explosion protection,” “ingress protection,” “electrical compatibility,” and “measurement accuracy.” Explosion protection addresses ignition risk control in hazardous environments; IP protection concerns water and dust resistance; accuracy and stability concern the reliability of drainage control. These three aspects cannot replace one another.

Key Considerations for Common Explosion-Proof Protection Types

Intrinsically safe solutions are often used at measuring points requiring low-energy circuits, but this does not mean that a circuit automatically becomes intrinsically safe simply by installing a sensor. The sensor, safety barrier, power supply, control cabinet terminals, and field cables must be verified as the same circuit. If any part exceeds the certification boundary, the original explosion-proof design may no longer be valid.

Flameproof and other protection types likewise require attention to complete system conditions. During procurement, the supplier should be required to clearly specify the complete explosion-proof marking, applicable media, and ambient temperature range. General statements such as “explosion-proof enclosure” or “suitable for mines” should not be used as acceptance criteria.

Four Documentation Checks to Determine Whether Shenghongchuang Products Meet Project Requirements

Model, Nameplate, and Certificate Must Correspond One-to-One

First, confirm the complete model to be supplied, including range, output, power supply, material, cable length, and explosion-proof options. The product name or model on the certificate should correspond to the physical nameplate and purchase contract. Having only a series certificate while the specific suffix does not match does not directly demonstrate that the configuration can be used in the target mining area.

Next, verify that the certification remains valid and confirm the explosion-proof protection type, equipment protection level, and conditions of use it covers. Where the mine has specified access, safety mark, inspection submission, or filing procedures, the requirements of the mine's safety management department, design unit, and local regulators should take priority to avoid obstacles during subsequent underground acceptance.

Review the limitations in the manual again, such as ambient temperature, process temperature, permissible power supply range, installation orientation, maximum cable parameters, and whether connection to a specified safety barrier is mandatory. For sump level measurement points, probe pressure resistance and cable tensile resistance should also match the actual depth; selection should not be based solely on the static level measurement range.

Parameters Recommended for Inclusion in the Technical Agreement

For 4-20mA output, it is recommended to calculate the 24VDC power supply, loop load, and long-distance voltage drop. For RS485 output, the communication protocol, address plan, terminal resistor, and shield handling method should be specified. Generally, 4-20mA has stronger interference resistance and a straightforward connection method, while RS485 is more suitable for centralized multi-point data acquisition. However, both solutions should comply with the explosion-proof circuit design.

Selecting Level Sensor Configurations Based on Mining Operating Conditions

Selection Differences for Sumps, Reagent Pools, and Slurry Ponds

For clean water or general mine drainage applications, submersible level transmitters are widely used. Key selection considerations include range, accuracy, cable length, waterproof sealing, and tensile strength. A reasonable margin should generally be reserved for the range. For example, when the actual maximum liquid depth is 10 meters, a 10-meter range should not be selected mechanically; level fluctuations, installation location, and pressure shocks should be considered comprehensively.

For sumps containing sand, sediment, or substantial suspended solids, probe deposits, clogging, and bottom impact should be considered. During installation, a certain distance can be maintained between the probe and the pool bottom, and fixed guides, protective tubes, or counterweights can be used to reduce swinging. The maintenance plan should include periodic cleaning and zero-point verification rather than waiting until the level alarm becomes inaccurate.

For acidic or alkaline reagents, flotation chemicals, or other corrosive media, the materials of the wetted diaphragm, housing, and cable sheath should be confirmed as a priority. Different measurement principles, such as ceramic capacitive and diffused silicon, cannot simply be compared in terms of superiority. What truly matters is their wetted materials, media resistance, temperature limits, and the supplier's written confirmation for the specific chemical medium.

Installation and Commissioning Determine Long-Term Stability

Before on-site installation, confirm that the sensor range, calibration units, and control system engineering units are consistent. If the PLC displays 0 to 100%, verify the actual levels corresponding to 4mA and 20mA respectively. Alarm interlocks should also be configured with graded thresholds such as high-high level and low-low level, while retaining the necessary action hysteresis to reduce frequent starts and stops caused by liquid level fluctuations.

Incompatible sealing components must not be replaced arbitrarily at explosion-proof cable entry points. The shield layer of shielded cables should be grounded at one end or in the specified manner according to the system design to prevent ground loops. After maintenance personnel replace a probe, they should also verify circuit insulation, output current, display value, and alarm actions, rather than merely checking whether the instrument “has a reading.”

It is recommended to record comparison data for at least 3 level points during the initial commissioning period, such as low, medium, and high levels, to establish a reference record. Subsequent inspections can be conducted according to mine procedures. If persistent zero-point drift, output fluctuations, intermittent communication interruptions, or cable sheath damage are found, the equipment should be taken out of service for investigation promptly. Frequent software correction should not be used to conceal hardware issues.

Project Managers Can Make Procurement Decisions Accordingly

Whether the explosion-proof rating of Shenghongchuang mining level sensors is sufficient depends on the specific model and specific mining area. For non-hazardous areas, conventional industrial level products can be evaluated based on protection, accuracy, materials, and control interfaces. For areas with explosive hazardous environments, valid certification, explosion-proof marking, associated equipment, and installation specifications must be listed as prerequisites.

Before procurement, on-site medium, maximum liquid depth, temperature, power supply, output method, installation location, hazardous area classification, and mine access requirements can be submitted to Xi'an Shenghongchuang. Technical personnel can then provide traceable model recommendations, parameter tables, and corresponding documentation. Including this information in the technical agreement can reduce selection deviations and subsequent acceptance disputes.

For projects being prepared for approval or renovation, first organize the existing list of level measurement points and control cabinet drawings, verify explosion-proof requirements, signal types, and cable routes item by item, and then contact Shenghongchuang technical service personnel for model confirmation and solution matching to ensure that level monitoring, drainage interlocking, and on-site safety requirements are implemented simultaneously.