Underground Coal Mine Multi Gas Detector

Introduction of Underground Coal Mine Multi Gas Detector 

The JD4(A) multi-parameter gas detection alarm is a professional intrinsically safe and flameproof gas monitoring device tailored for underground coal mine environments. Complying with national and industrial standards including GB/T 3836 series and AQ/T 6207-2007, this portable detector is designed for continuous real-time monitoring of four critical mine gases: methane (CH4), oxygen (O2), carbon monoxide (CO), and carbon dioxide (CO2).

 

Engineered for harsh underground working conditions, the device operates stably at temperatures from 0℃ to 40℃, relative humidity up to 98%, and atmospheric pressure of 80kPa to 116kPa, adapting to complex mine airflow and dust environments. With an IP68 protection grade, it withstands 1.1m water immersion for 40 minutes and resists daily collisions and dust erosion. Weighing only 259.5g with a compact size of 115.0mm×63.0mm×41.0mm, it is lightweight for portable carrying by mine workers, supervisors and ventilation staff, and also supports fixed-point installation for long-term environmental monitoring.

 

Feature of Underground Coal Mine Multi Gas Detector

1) It delivers high-precision and fast-response gas detection. It covers full-range detection of four core gases with strictly controlled basic and alarm errors. The response time is no more than 20s for methane, 30s for carbon dioxide, 35s for oxygen and 45s for carbon monoxide, ensuring timely capture of gas concentration changes. Dual-level adjustable alarm thresholds are preset for all gases, matching mainstream coal mine safety specifications effectively.

 

2) It adopts a triple safety alarm system combining sound, light and vibration. The alarm sound intensity reaches over 80dB (1 meter away), and the alarm light is visible within 20 meters in dark environments, guaranteeing effective alerts in noisy and dim underground spaces. Optional intelligent functions further upgrade safety performance: the fall alarm detects staff falls under normal or gas-over-limit conditions, while linkage alarm realizes 100m visual-distance wireless alarm interaction among devices, achieving regional safety linkage monitoring. The manual emergency alarm function supports active risk reporting in sudden danger.

 

3) It integrates diverse practical intelligent functions. It supports real-time temperature and humidity display, timing calibration reminders, customizable screen-off time and data storage intervals. Built with data export function, it records gas concentration and alarm data with accurate time stamps for safety inspection and accident traceability. The 4-digit password protection prevents misoperation, and the factory reset function facilitates daily equipment management. Equipped with a dedicated intrinsic safety manganese lithium battery pack, it provides over 10 hours of continuous working time, meeting full-shift underground operation needs. The optional cascade charging design allows 20 devices to be charged simultaneously with one adapter, greatly improving charging efficiency for team equipment.

 

4) In terms of safety reliability, the whole machine adopts mine-explosion-proof design with the Exdb ib I Mb explosion-proof mark. The intrinsic safety circuit and encapsulated battery assembly eliminate underground explosion risks. Strictly manufactured in accordance with multiple industry standards, it features stable performance, low failure rate and long service life.

 

Detail photos of Underground Coal Mine Multi Gas Detector

 

Product parameters of Underground Coal Mine Multi Gas Detector

Item	Parameters
Detectable Gas Types	Methane (CH4) Oxygen (O2) Carbon Monoxide (CO) Carbon Dioxide (CO2)
Detection Range	CH4: (0.00～4.00)%CH4 O2: (0.0～30.0)%O2 CO: (0～1000)×10 CO CO2: (0.00～5.00)%CO2
Basic Accuracy Error	CH4: ±0.10%CH4 (0.00～1.00%)±10% of true value (1.00～3.00%)±0.30%CH4 (3.00～4.00%) O2: ±0.5%O2 (0.0～5.0%)±3%FS (5.0～30.0%) CO: ±2% (0～20×10 CO)±4% (＞20～100×10 CO)±5% of true value (＞100～500×10 CO)±6% of true value (＞500～1000×10 CO) CO2: ±0.10% (0.00～0.50%)±(0.05 + 5% of true value) (0.50～5.00%)
Alarm Performance	Alarm Performance
Alarm Signal	Three-dimensional alarm: sound, light and vibration
Alarm Sound Intensity	≥80dB(A) (1 meter away from the buzzer)
Alarm Visibility (Light)	Visible distance ≥20m in dark environment
Two-Stage Alarm Threshold (Full range adjustable)	CH4: Factory primary alarm point: 1.00%CH4; Secondary alarm point:1.50%CH4 O2: Factory primary alarm point: 18.0%O2; Secondary alarm point: 16.0%O2 CO: Factory primary alarm point: 24×10-6 CO; Secondary alarm point: 48×10-6 CO CO2: Factory primary alarm point: 1.0%CO2; Secondary alarm point: 1.5%CO2
Alarm Error	CH4: ±0.05%CH4 O2: ±0.3%O2 CO: ±1×10 CO CO2: ±0.04%CO2
Response Time (Flow rate: 250mL/min)	CH4: ≤20s O2: ≤35s CO: ≤45s CO2: ≤30s
Main Functions	Main Functions
Fall Alarm (Optional)	The detector can monitor the fall status of the wearer and display the fall icon under normal gas concentration conditions. It can also trigger fall detection when gas concentration exceeds the limit. With linkage alarm enabled, fall alarm signals will be automatically sent to detectors within 100 meters (visible distance).
Linkage Alarm (Optional)	When enabled, linkage alarm is available within 100 meters (visible distance). Frequency range: 2400～2525MHz; Maximum wireless transmit power: ≤20dBm.
Emergency Alarm	Long press the emergency alarm button to activate the manual alarm interface and actively send alarm signals to surrounding detectors.
Calibration Reminder	Once enabled, the detector will pop up an over-calibration reminder on startup when the calibration period expires.
Temperature & Humidity Detection	Real-time temperature and humidity display on the monitoring interface.
Password Setting	4-digit password available for menu access and shutdown permission; factory default: disabled.
Factory Reset	Clear stored data and custom settings to restore factory defaults.
Screen-off Time	Adjustable: 0 (always on) or 1～20 minutes.
Data Storage Interval	Customizable interval for real-time data collection and storage.
Time Setting	Adjustable year, month, day, hour and minute.
Data Export	Supports exporting dated alarm data via the dedicated charging base.
Cascade Charging (Optional)	The charging base supports cascade connection for up to 20 units, enabling simultaneous charging of 20 detectors with a single adapter.
Power Supply	Power Supply
Continuous Working Time	≥10 hours under normal working conditions*Subject to operating status, alarm frequency and activation of indicator lights & reminder functions
Battery Specification	Intrinsic safety power supply: 2 parallel lithium manganate batteries, Model: QHPW 674048, 1120mAhMaximum open-circuit voltage (Uo): 4.3VMaximum output current (Io): 2.1ARated working voltage (Ue): 3.7VEquipped with two-stage protection circuit and encapsulated with epoxy resin to form an intrinsic safety battery assembly.
Dimension & Weight	Dimension & Weight
Overall Dimension	Approx. 115.0mm×63.0mm×41.0mm (including back clip)
Weight	Approx. 259.50g (including back clip)
Protection Grade	Protection Grade
IP Rating	IP68 (1.1m water depth, 40 minutes duration)

 

FAQ about Underground Coal Mine Multi Gas Detector 

Q1: Is the detector available for underground charging?

A1: No. To ensure underground explosion-proof safety, charging and battery replacement are strictly prohibited in coal mines. All charging operations must be completed in ground safety areas with the supporting dedicated X61E power adapter, and the device must be powered off before charging.

 

Q2: How to solve inaccurate detection or zero drift?

A2: Zero drift in clean air can be fixed by professional zero calibration (CH4 and CO in clean air, O2 and CO2 in pure nitrogen). If detection data is inaccurate, perform standard gas calibration with matched concentration gas. If calibration fails or data is still abnormal, the sensor may be aging and needs professional replacement.

 

Q3: What causes short working time and failure to charge?

A3: Short working time is mainly caused by aging batteries or faulty chargers. If the device fails to charge, first check and replace the charger. If the problem persists, it is a device internal fault and needs factory maintenance.

 

Q4: Are the linkage and fall alarm functions standard?

A4: The two functions are optional configurations. After activation, linkage alarm supports 2400-2525MHz wireless signal transmission, and fall alarm automatically identifies staff falling status and synchronizes alarm information with surrounding devices.

 

Q5: What is the warranty policy?

A5: The host enjoys a 12-month free warranty, and the battery has a 6-month warranty. Damage caused by human operation, unauthorized disassembly, natural disasters and over-warranty faults are not covered by free maintenance.