Honeywell BW™ Flex 4/5
Swift Marine Tech Services Pte Ltd is a supplier of Honeywell BW™ Flex 4/5 CO₂ Gas Detectors in Singapore, providing portable multi-gas detection solutions for marine, offshore, industrial, and confined-space safety applications.
The Honeywell BW Flex 4/5 is a compact, rugged, and lightweight multi-gas detector designed to protect personnel from multiple gas hazards. With a choice of 14 different sensor types, the instrument can be configured with up to four sensors to detect up to five gas hazards, depending on the selected sensor combination.
The available sensor options include combustible gases, oxygen, carbon dioxide (CO₂), hydrogen sulphide (H₂S), carbon monoxide (CO), sulphur dioxide (SO₂), chlorine (Cl₂), nitric oxide (NO), nitrogen dioxide (NO₂), and hydrogen cyanide (HCN).
The CO₂ version uses an NDIR (Non-Dispersive Infrared) sensor for carbon dioxide measurement, making it suitable for applications where monitoring CO₂ concentration is required alongside other selected gas hazards.
Honeywell BW Flex 4/5 – Advanced Portable Multi-Gas Detection Technology
The Honeywell BW Flex 4/5 combines multiple gas-sensing technologies in a single portable instrument. Its modular sensor configuration allows users to select suitable sensors according to their workplace gas-monitoring requirements.
For CO₂ monitoring, the instrument is available with an NDIR CO₂ sensor. The detector also supports different electrochemical, catalytic bead, and infrared sensor technologies for other gas detection requirements.
Its compact design, visual and audible alarms, vibration alerts, and Bluetooth connectivity support personnel working in industrial facilities, marine environments, offshore installations, and confined spaces.
Honeywell BW Flex 4/5 – IP66 and IP68 Protection for Marine and Industrial Environments
The Honeywell BW Flex 4/5 is designed with a compact and rugged housing for everyday industrial use.
The manufacturer specifies IP66 and IP68 ingress protection ratings. Its construction makes it suitable for a range of indoor and outdoor applications, including industrial, marine, offshore, and mining environments, subject to the relevant instrument and sensor approvals.
Its compact dimensions and lightweight construction also support personal gas-monitoring applications where wearable equipment is required.
Honeywell BW Flex 4/5 – Reflex™ Automatic Sensor Diagnostics
The BW Flex 4/5 includes diagnostic functions to help verify instrument operation.
When activated, the detector performs diagnostics of its sensors and circuitry. Its Reflex™ test automatically performs an analogue sensor diagnostic every 10 minutes.
These functions support instrument monitoring and help identify certain sensor or instrument issues during operation.
Honeywell BW Flex 4/5 – Calibration, Maintenance and IntelliDoX Compatibility
The modular design of the Honeywell BW Flex 4/5 supports servicing and maintenance.
The detector is compatible with the Honeywell IntelliDoX automated test and calibration system, supporting routine instrument management.
Honeywell specifies a maximum calibration interval of up to 180 days for most sensor types, while the HCN sensor has a maximum interval of 90 days. Actual calibration and bump-test requirements must follow the applicable sensor instructions, manufacturer guidance, and workplace procedures.
Honeywell BW Flex 4/5 – CO₂ Replacement Sensor and Spare Parts
For maintenance and replacement requirements, Honeywell provides individual replacement sensors for the BW Flex 4/5 Series.
The CO₂ replacement sensor is identified by the following manufacturer part number:
CO₂ NDIR replacement sensor: SR-B1-1S
Other replacement sensors are available for selected gas types, including oxygen, LEL, H₂S, CO, SO₂, NO, NO₂, HCN, and Cl₂.
Customers should confirm the installed sensor identifier and instrument configuration before ordering replacement sensors.
Honeywell BW Flex 4/5 CO₂ Gas Detector – Product Overview
The Honeywell BW Flex 4/5 is designed for daily personal gas monitoring in environments where workers may be exposed to multiple gas hazards.
The CO₂ configuration uses the NDIR sensor identified by Honeywell as sensor identifier B1, with spare sensor part number SR-B1-1S.
The instrument provides a clear display of gas readings and configurable alarm settings. Users can configure the display to show all measured gases simultaneously or one gas at a time.
The detector also features Honeywell IntelliFlash™ and SafetyTick™ status indicators, providing visual instrument-status information through green, amber, and red indications.
Honeywell BW Flex 4/5 – Available Gas Sensor Configurations
The Honeywell BW Flex 4/5 Series offers 14 sensor types for different gas-monitoring requirements.
Available sensor options include:
LEL-IR: Infrared combustible gas detection
NDIR-CO₂: Carbon dioxide detection
LEL-CB-F: Catalytic bead, filtered
LEL-CB-UF: Catalytic bead, unfiltered
O₂: Oxygen detection
H₂S: Hydrogen sulphide detection
CO: Carbon monoxide detection
CO-H: Hydrogen-compensated carbon monoxide detection
SO₂: Sulphur dioxide detection
NO: Nitric oxide detection
NO₂: Nitrogen dioxide detection
HCN: Hydrogen cyanide detection
Cl₂: Chlorine detection
COSH Dual Toxic: Combined H₂S and CO detection
Note: Not every sensor combination is recommended or permitted. Honeywell advises checking sensor compatibility because of possible cross-sensitivity and interference.
Honeywell BW Flex 4/5 CO₂ Detector – NDIR Carbon Dioxide Measurement
The Honeywell BW Flex 4/5 can be configured with an NDIR carbon dioxide sensor, identified by Honeywell as sensor identifier B1.
NDIR technology is used to measure carbon dioxide concentration through infrared absorption. This sensor configuration is designed for applications where monitoring CO₂ levels is required as part of personal gas detection.
The manufacturer’s specifications for the CO₂ sensor include:
Sensor technology: NDIR
Gas detected: Carbon dioxide (CO₂)
Recommended operating range: 5% VOL (50,000 ppm)
Maximum over-range: 5% VOL (50,000 ppm)
Resolution: 0.01% VOL (100 ppm)
Default low alarm: 0.5% VOL (5,000 ppm)
Default high alarm: 3.0% VOL (30,000 ppm)
Replacement sensor part number: SR-B1-1S
The detector’s alarm settings can be configured using compatible Honeywell software and applications, subject to the instrument configuration.
Honeywell BW Flex 4/5 – Four-Sensor Configuration and Five-Gas Hazard Protection
One of the main advantages of the Honeywell BW Flex 4/5 is its flexible sensor configuration.
The detector supports the installation of up to four sensors selected from the available sensor range. With compatible dual-toxic sensor configurations, it can provide protection against up to five gas hazards.
This flexibility allows users to select an instrument configuration according to the gases present in their workplace rather than relying on a single fixed gas combination.
The final sensor combination should be confirmed with Honeywell because certain combinations may not be recommended or permitted due to cross-sensitivity and sensor interference.
Key Features of Honeywell BW Flex 4/5 CO₂ Gas Detector
1. NDIR CO₂ Sensor Technology
The Honeywell BW Flex 4/5 can be configured with an NDIR carbon dioxide sensor for measuring CO₂ concentrations.
The CO₂ sensor provides a measurement range of 0–5% volume, equivalent to 0–50,000 ppm, with a resolution of 0.01% volume (100 ppm).
2. Multi-Gas Detection Capability
The detector supports a choice of 14 sensor types, allowing users to configure the instrument for different combinations of combustible, oxygen, and toxic gas hazards.
With up to four installed sensors, the instrument can provide protection against up to five gas hazards when a compatible dual-toxic sensor configuration is selected.
3. Visual, Audible and Vibration Alarms
The instrument provides multiple alarm types to alert personnel when gas concentrations reach configured alarm levels.
Alarm indications include:
Visual LED alarms
Audible alarm (95 dB)
Vibration alarm
Low and high gas alarms
Time Weighted Average (TWA) alarms
Short-Term Exposure Limit (STEL) alarms
Over-limit and other instrument-status alarms
4. Bluetooth Connectivity
The Honeywell BW Flex 4/5 supports Bluetooth Low Energy (BLE) connectivity
Honeywell BW Flex 4/5 – Available 14 Gas Sensor Types
Honeywell offers a selection of sensor technologies for the BW Flex 4/5 Series.
Available sensor options include:
Combustible Gas Sensors
LEL-IR – Infrared combustible gas sensor
LEL-CB-F – Catalytic bead, filtered
LEL-CB-UF – Catalytic bead, unfiltered
Oxygen Sensor
O₂ – Oxygen sensor
Carbon Dioxide Sensor
NDIR-CO₂ – Non-Dispersive Infrared carbon dioxide sensor
Toxic Gas Sensors
H₂S – Hydrogen sulphide
CO – Carbon monoxide
CO-H – Hydrogen-compensated carbon monoxide
SO₂ – Sulphur dioxide
NO – Nitric oxide
NO₂ – Nitrogen dioxide
HCN – Hydrogen cyanide
Cl₂ – Chlorine
Dual-Toxic Sensor
COSH – Combined carbon monoxide and hydrogen sulphide detection
The selection of sensors depends on the required gas hazards, application, and instrument configuration.
Honeywell BW Flex 4/5 – Intelligent IntelliFlash™ and SafetyTick™ Status Indicators
The Honeywell BW Flex 4/5 incorporates visual status indicators to help personnel identify the instrument’s operating status.
Its IntelliFlash™ and SafetyTick™ indicators use colour-coded visual signals:
Green – Indicates the instrument is in the good-to-go status.
Amber – Indicates a warning or attention condition.
Red – Indicates a stop or alarm condition.
The ultra-bright LED indicators provide a visible status indication to assist workers and supervisors during field operations.
Why Choose Swift Marine Tech Services Pte Ltd?



Swift Marine Tech Services Pte Ltd supports marine and industrial customers with equipment supply and product enquiries.
We assist customers in identifying suitable gas detection equipment according to their application requirements, selected gas sensors, and operating environments.
Our support includes:
Honeywell BW Flex 4/5 portable gas detector enquiries
CO₂ NDIR sensor configuration enquiries
Replacement sensor identification
Portable multi-gas detector product information
Technical datasheet assistance
Marine and industrial gas detection equipment supply enquiries
For the correct detector configuration, customers are encouraged to provide the required gas list and application details before confirming an order.
Swift Marine Tech Services Pte Ltd – Marine and Industrial Equipment Supplier in Singapore
Swift Marine Tech Services Pte Ltd supports marine, offshore, and industrial customers in Singapore and international markets with equipment supply enquiries.
We assist vessel operators, ship managers, shipyards, offshore companies, marine service providers, and industrial customers with product information and equipment requirements.
Contact Swift Marine Tech Services Pte Ltd – Honeywell BW Flex 4/5 Supplier in Singapore
Looking for a Honeywell BW Flex 4/5 CO₂ Gas Detector in Singapore?
Contact Swift Marine Tech Services Pte Ltd for product information, CO₂ sensor configuration enquiries, replacement sensor requirements, and quotations.
Our team can assist with identifying the suitable Honeywell BW Flex 4/5 configuration according to your required gas detection application.