Bosean BH-4M

Contents

Bosean BH-4M Multi Gas Detector User Manual

Model: BH-4M

Brand: Bosean

1. Introduction

The Bosean BH-4M is a versatile multi-gas detector designed for real-time detection of multiple gases, including Oxygen (O2), Carbon Monoxide (CO), Hydrogen Sulfide (H2S), and Combustible Gases (LEL). Founded in 2013, Bosean specializes in the development and production of gas detectors and analyzers, adhering to ISO9001, CE, ATEX, and ROHS quality management systems.

This device features a robust, three-proof design (waterproof, dustproof, explosion-proof) and offers two sampling options: natural diffusion and pump suction. It is equipped with high-quality electrochemical sensors, made in the UK, and comes factory calibrated for immediate use.

Bosean BH-4M Multi Gas Detector with three-proof design, showing water droplets on its surface.
Figure 1: Three-proof design (waterproof, dustproof) of the gas detector.
Visual comparison of Natural diffusion type and Pump type gas detectors, explaining their sampling methods.
Figure 2: Natural Diffusion Type vs. Pump Type Gas Detector.

The natural diffusion type allows gas to flow freely into the instrument for inspection, while the pump type provides active detection, fast response, and long-distance measurement for dangerous areas or personnel safety.

2. Warning & Safety Information

WARNING:

  • Be aware of potential fire hazards.
  • Strictly follow this instruction manual for charging and storage.
  • Avoid high-temperature and humid environments.
  • For disposal of the built-in lithium-ion battery, please consult your local authority's website for further information and safely dispose of it in accordance with applicable legal requirements.

3. Product Components and Packaging

The BH-4M gas detector comes with the following items:

  • 1 x 4-in-1 Multi Gas Monitor (BH-4M)
  • 1 x English User Manual
  • 1 x Charging Adaptor
  • 1 x USB Charging Cable (Type-C)
  • 1 x Calibration Cover
  • 1 x Metal Aluminum Box
  • 1 x Certificate
  • (Optional: Ventilation hose and screwdriver may be included depending on package variant)
Diagram illustrating the contents of the product packaging, including gas detector, calibration cover, user manual, certificate, charging adaptor, Type-C cable, ventilation hose, and screwdriver.
Figure 3: Packaging Contents.

The device features a 2.0-inch HD color screen, three intuitive buttons for operation, and a durable Type-C interface for charging and data communication.

Diagram of the gas detector highlighting four alarm types (light, sound, vibration, screen display) and components like gas hole, LED, alarming lights, buzzer hole, gas sampling pump, HD color screen, and Type C interface.
Figure 4: Key components and alarm indicators.

4. Initial Setup and Charging

4.1 Charging the Device

The BH-4M is powered by a built-in 3.7V 2500mAh lithium-ion battery. Before first use, ensure the device is fully charged.

  1. Connect the provided Type-C USB charging cable to the device's Type-C interface.
  2. Connect the other end of the cable to the charging adaptor and plug it into a power outlet.
  3. The charging time is typically less than 5 hours.
  4. A full charge provides approximately 8-10 hours of continuous use (8 hours with pump, 10 hours without pump).
Graphic illustrating long battery life (>=10 hours without pump, >=8 hours with pump) from a 2500mAh lithium battery.
Figure 5: Battery life indication.

4.2 Language Setting

The device supports Chinese and English language switching. Refer to the on-screen menu for language selection.

Images showing the 2.0-inch HD color screen and the option for Chinese and English language switching.
Figure 6: Language selection on the HD color screen.

5. Operating Instructions

The BH-4M is designed for simple and intuitive operation using its three-button interface.

  1. Turn on the power switch: Press and hold the power button until the device powers on and the HD color screen displays information.
  2. Place the device in the detection area: Position the gas detector in the environment where gas detection is required.
  3. View the numerical display: Observe the real-time gas concentration readings on the 2.0-inch HD color screen.

5.1 Sampling Methods

The device supports both natural diffusion and pump suction sampling methods. The sampling mode can be switched as needed to suit different detection requirements.

  • Natural Diffusion Type: Gas in the inspected area flows freely with the air, and the sample gas flows into the instrument for inspection.
  • Pump Type: Active detection with a miniature vacuum sampling pump for fast detection speed and long-distance measurement in dangerous areas or for personnel safety.
Image showing both the pump type and natural diffusion type gas detectors side-by-side.
Figure 7: BH-4M with and without pump.

6. Alarm System

The BH-4M features a comprehensive four-alarm system to alert users to hazardous gas levels:

  • Sound Alarm: An audible alert up to 80dB.
  • Light Flashing: Visual indication via alarming lights.
  • Vibrating Alert: Tactile feedback for discreet or noisy environments.
  • Screen Display: Visual alerts and gas concentration readings on the HD screen.

Users can set adjustable low and high alarm values, as well as STEL (Short-Term Exposure Limit), TWA (Time-Weighted Average), and OL (Over Limit) alarm functions.

7. Data Management

The device supports data and alarm record storage, capable of storing up to 500 alarm records. These records can be imported into a computer for sorting and analysis using a Type-C data cable connection and compatible software.

Image showing the gas detector connected to a laptop, illustrating data/alarm record storage and Type C data cable connection for up to 100K records.
Figure 8: Data/alarm record storage and computer connection.

8. Maintenance and Precautions

  • Environment: Avoid operating or storing the device in high-temperature or humid environments. The recommended operating humidity is <95%RH (non-condensing).
  • Cleaning: Keep the device clean and free from dust and debris.
  • Calibration: The sensors come factory calibrated. Regular calibration may be required to maintain accuracy over time. Refer to the user manual for calibration procedures or contact support.
  • Battery Care: Follow safety guidelines for lithium-ion batteries. Do not expose to extreme temperatures or physical damage.

9. Troubleshooting

Frequently Asked Questions (FAQ)

Q: The device shows "No display". What should I do?
A: Check the battery level. If the battery is low, charge the device. If the battery is sufficient, try restarting the device.

For other issues, please refer to the full user manual (PDF) or contact customer support.

10. Specifications

Parameter Detail
Model Number BH-4M
Gas Type Detected Oxygen (O2), Hydrogen Sulfide (H2S), Carbon Monoxide (CO), Combustible Gas (LEL)
O2 Sensor Range 0-30%vol
H2S Sensor Range 0-100ppm
CO Sensor Range 0-1000ppm
LEL Sensor Range 0-100%LEL
Resolution 0.1%vol (O2), 1ppm (H2S, CO), 1%LEL (Combustible)
Detection Error ≤±5% F.S.
Response Time (T90) <30s (Pump type), <60s (Natural diffusion type)
Alarm Methods Sound (up to 80dB), Light, Vibration, Screen Display
Display 2.0-inch HD Color Screen (320*240 resolution)
Battery 3.7V 2500mAh Li-battery (Built-in)
Battery Runtime ≥8 hours (with pump), ≥10 hours (without pump)
Charging Time <5 hours (Type-C interface, 5V/1A standard charger)
Sensor Life 2 years
Data Storage 500 alarm records (up to 100K via Type-C connection)
Working Environment -20℃ to 50℃ (for toxic gas), 0℃ to 40℃ (for LEL)
Operating Humidity <95%RH (no dew)
System Language Chinese, English (switchable)
Product Net Weight Approx. 335g (Natural diffusion type), Approx. 372.5g (Pump type)
Dimensions (L×W×H) 145mm × 69mm × 28mm (Natural diffusion type: 150mm H, 55mm W, 69mm D; Pump type: 160mm H, 75mm W, 69mm D)
Certification CE
Table detailing target gas, range, low alarm, high alarm, and resolution for CH4, H2S, CO, and O2.
Figure 9: Gas detection ranges and alarm thresholds.
Detailed specifications table including sampling method, gas detection, alarm mode, response time, work environment, power, display mode, data communication, system language, charger, standby time, charging time, and sensor life.
Figure 10: Comprehensive product specifications.
Dimensions and weight comparison for the pump type and natural diffusion type gas detectors.
Figure 11: Dimensions and weight for different types.

11. User Tips

  • Always ensure the device is fully charged before extended use to maximize battery life.
  • Familiarize yourself with the alarm settings and adjust them according to the specific safety requirements of your working environment.
  • Regularly check the sensor's expiration date and consider professional calibration to maintain optimal accuracy.

12. Warranty and Support

For detailed warranty information, technical support, or service inquiries, please refer to the official Bosean website or contact your authorized dealer. A comprehensive user manual in PDF format is available for download at this link.

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