cWH850 Intrinsically Safe Mining Infrared Thermometer

Overview

The cWH850 Intrinsically Safe Mining Infrared Thermometer is a certified portable non-contact temperature measurement instrument engineered for hazardous underground coal mine environments where explosive atmospheres—comprising methane (CH₄) and combustible coal dust—are present. It operates on the principle of infrared radiometry: incident thermal radiation emitted by a target surface within the 6–14 µm spectral band is collected via an optical system, focused onto a thermopile or pyroelectric sensor, converted into a proportional electrical signal, conditioned, linearized, and displayed as a calibrated temperature value on a high-contrast backlit LCD. Its intrinsic safety design ensures that no single fault or combination of two faults can generate sufficient energy—thermal or electrical—to ignite a flammable gas–air mixture under defined ambient conditions. This makes the cWH850 compliant with IEC 60079-0 and IEC 60079-11 for equipment protection level “Mb”, denoting suitability for use in Zone 0 and Zone 1 mining environments per GB 3836.1–2021 and GB 3836.4–2021 standards.

Key Features

• Dual Class II visible red laser targeting system (630–670 nm, <1 mW) enables precise spatial alignment and verification of measurement spot location at distance, critical for assessing conveyor bearings, electrical terminations, or hydraulic couplings in low-light tunnel conditions.
• Adjustable emissivity (0.10–1.00 in 0.01 increments) supports accurate measurement across diverse mine materials—including oxidized steel, wet coal, refractory linings, rubber belts, and painted surfaces—without requiring surface preparation.
• High-speed response (<400 ms) allows rapid scanning of moving components such as rotating drum sheaves, belt idlers, or ventilation fan housings without motion-induced error.
• Robust mechanical architecture meets IP54 ingress protection: dust-resistant against limited ingress and protected against water splashing from any direction—essential for damp, dusty shafts and development headings.
• Integrated data management functions include MAX/MIN/DIF/AVG calculation, trigger hold, auto-hold on stabilization, and programmable HAL/LAL alarms with visual and audible indication—enabling real-time thermal anomaly detection during preventive maintenance inspections.
• Optional onboard memory stores up to 20 sequential measurements with timestamp (when used with compatible external logging interface), supporting traceability requirements for GLP-aligned inspection records.

Sample Compatibility & Compliance

The cWH850 is validated for non-contact surface temperature measurement of metallic, ceramic, composite, and organic materials commonly encountered in coal mining infrastructure—including but not limited to: motor windings, transformer bushings, cable splices, brake drums, hydraulic reservoirs, air compressors, and ventilation ductwork. It is not intended for measuring transparent media (e.g., glass, quartz) or highly reflective bare metals without emissivity correction. The device carries the China National Coal Mine Safety Certification Center (KA) approval mark “Exib I Mb” and complies with mandatory national standards GB 3836.1–2021 (Explosive Atmospheres – Part 1: Equipment – General Requirements) and GB 3836.4–2021 (Intrinsically Safe Systems). It is also certified per AQ 1043–2007 (Safety Technical Specification for Intrinsically Safe Electrical Equipment in Coal Mines). All certification documentation—including Safety Approval Certificate, Explosion-Proof Test Report, and EMC test reports—is available upon request for audit readiness.

Software & Data Management

While the cWH850 operates as a standalone field instrument, its optional RS232 or USB interface (via accessory cable) permits connection to PC-based diagnostic software for batch export of stored readings, report generation (PDF/CSV), and trend analysis. Software features include calibration log tracking, user-defined asset tagging, pass/fail threshold overlays, and audit trail generation aligned with ISO/IEC 17025 documentation requirements. Firmware updates are delivered via secure authenticated download to maintain metrological integrity over service life. Data export supports integration with CMMS platforms such as SAP PM or IBM Maximo through standard CSV schema mapping.

Applications

• Preventive maintenance of electromechanical systems: monitoring bearing temperatures on conveyors, fans, pumps, and hoists to detect early-stage lubrication failure or misalignment.
• Electrical safety inspections: identifying overheated connections, switchgear contacts, and transformer cooling anomalies before thermal runaway occurs.
• Mine ventilation assessment: verifying heat dissipation profiles across air coolers, duct joints, and regulator doors to ensure compliance with ventilation resistance specifications.
• Fire risk surveillance: detecting spontaneous combustion precursors in stockpiled coal, gob areas, or sealed entries via localized hot-spot mapping.
• Regulatory compliance audits: supporting MSHA Part 31 and DLGS 44–2019 reporting obligations for thermal integrity of active mining zones.
• Emergency response triage: rapid assessment of equipment thermal status during rescue operations without introducing ignition sources.

FAQ

What does “Exib I Mb” signify?
It denotes “Intrinsically Safe” protection level “Mb”, certified for use in underground coal mines where ignitable concentrations of methane and coal dust may be continuously present (Zone 0 equivalent). “I” indicates Group I (mining), “b” indicates protection level suitable for Zone 1, and “Mb” confirms compliance with IEC 60079-11 for equipment intended for use in coal mines.
Can the cWH850 measure through smoke or steam?
No. Obscurants such as dense smoke, water vapor, or airborne coal dust attenuate infrared radiation in the 6–14 µm band and will result in inaccurate or invalid readings. Measurements must be performed in line-of-sight conditions with clear atmospheric path.
Is calibration traceable to national standards?
Yes. Factory calibration is performed using blackbody sources traceable to NIM (National Institute of Metrology, China) and documented in the Certificate of Calibration supplied with each unit. Field recalibration intervals are recommended annually or after mechanical shock, per JJF 1107–2003 guidelines.
Does the device support data export for regulatory reporting?
Yes—when equipped with the optional communication module, it exports timestamped readings in CSV format compatible with Excel, LabVIEW, and enterprise CMMS platforms. Audit logs include operator ID, location tag, and environmental conditions if externally logged.
What is the minimum measurable spot size at 1 meter distance?
With a 16:1 distance-to-spot ratio, the optical resolution at 1 m is approximately 62.5 mm diameter—ensuring reliable measurement of typical mining hardware components such as 60 mm-diameter motor bearings or 80 mm-diameter pipe flanges.