Extech EZ40

EzFlex™ Combustible Gas Detector

The EZ40 is built for the awkward half of leak hunting — the joint behind the geyser, the union inside a ceiling void, the fitting under a gas hob. Its 406 mm (16 in) gooseneck holds any shape you bend it into, so the sensor tip stays where you put it while both eyes stay on the readout. A thumb-controlled sensitivity wheel lets you dial out background gas as you get closer, which is what converts a general "there is a leak in this room" into an exact fitting. Visual and audible alarm triggers at 10% of the Lower Explosive Limit for methane, well below any ignition risk.

• Probe406 mm (16 in) gooseneck
• AlarmVisual + audible at 10% LEL methane
• AdjustmentOne-hand thumb sensitivity wheel
• Power3 × C batteries (supplied)
• Best forPinpointing leaks in tight, hidden spaces

Extech FG100

Combustible Gas Leak Detector — LNG & LPG

Where the EZ40 is about reach, the FG100 is about speed and range. It responds to liquefied natural gas and liquefied petroleum gas from 500 to 6500 ppm, which brackets the concentrations you encounter walking a gas line from bottle to appliance: a faint background at the far end of the run, climbing sharply as you approach the leaking joint. Audible and visual alarms fire together, and separate LED indicators distinguish a real gas reading from static absorption so you are not chased by false positives. Up to four hours of continuous operation covers a full inspection round.

• DetectsLNG & LPG, 500–6500 ppm
• AlarmAudible + visual
• IndicatorsSeparate LEDs for gas leak and static absorption
• RuntimeUp to 4 hours continuous
• Best forWalking LPG and natural gas lines quickly

Extech RD350

Refrigerant Leak Detector with Audible & Visual Alerts

Modern HFC refrigerants are non-flammable, so a combustible gas sniffer walks straight past a leaking R-410A joint. The RD350 uses a heated diode sensor that responds specifically to halogenated compounds, covering R-22, R-32, R-134a, R-404A, R-407C, R-410A, HFO-1234yf and all CFCs, HCFCs and HFCs. At its high setting it resolves a loss of roughly 3 g per year — small enough to catch a slow seep long before the system loses performance. A tri-colour LED bar shows leak level rather than a bare on-off alarm, so you can follow the concentration gradient along a pipe run to the exact fitting, and the variable-tone audible alarm lets you work with your eyes on the joint. The 400 mm flexible probe reaches into condenser coils and behind evaporator panels; warm-up takes 45 seconds.

• SensorHeated diode
• RefrigerantsR-22, R-32, R-134a, R-404A, R-407C, R-410A, HFO-1234yf, all CFC/HCFC/HFC
• SensitivityHigh 3 g/yr (HFC group); 4 g/yr for R-22
• Probe400 mm (15.5 in) flexible
• Warm-up45 seconds
• CertificationCE · 2 year warranty

Extech CO10

Carbon Monoxide (CO) Meter — 0 to 1000 ppm

Carbon monoxide has no colour, smell or taste, which is precisely why it kills people who had no reason to suspect anything was wrong. The CO10 makes it visible. A gas-specific electrochemical sensor gives a stabilised, fast-response reading from 0 to 1000 ppm at 1 ppm resolution, with basic accuracy of ±5% or ±10 ppm, whichever is greater. The audible alarm starts at 35 ppm, the level at which prolonged exposure becomes a health concern rather than the level at which symptoms appear — giving you margin to ventilate and investigate. The backlit 1999-count display stays readable in the dim plant rooms, roof spaces and generator enclosures where CO problems usually live.

• Range0–1000 ppm CO, 1 ppm resolution
• Accuracy±5% or ±10 ppm (greater of)
• SensorGas-specific electrochemical, fast response
• AlarmAudible from 35 ppm
• DisplayBacklit 1999-count LCD

Extech CO100

Desktop Indoor Air Quality CO2 Monitor

Carbon dioxide is the cheapest reliable proxy for whether a room is actually being ventilated. People exhale it continuously, so a rising CO2 curve in an occupied classroom, boardroom or clinic waiting area means air is being recirculated rather than replaced — and the same stagnant air carries everything else with it. The CO100 reads 0 to 9999 ppm on a maintenance-free NDIR infrared sensor with no consumable element to replace, and translates the number into plain guidance on screen: Good below 800 ppm, Normal from 800 to 1200 ppm, Poor above 1200 ppm. Temperature and humidity are logged alongside, a user-programmable alarm warns when a threshold is crossed, and automatic baseline calibration against fresh air keeps it honest over years of use.

• CO2 range0–9999 ppm, NDIR sensor
• Temperature−10 to 60°C
• Humidity0.1–99.9% RH
• IAQ bandsGood <800 · Normal 800–1200 · Poor >1200 ppm
• ExtrasProgrammable alarm, max/min recall, clock, ABC calibration

Extech CO220

Desktop CO2 Monitor with TWA & STEL Statistics

The CO220 is the CO100's reporting-grade sibling. It carries the same maintenance-free NDIR carbon dioxide sensor and the same temperature and humidity channels, then adds the calculations that turn a spot reading into evidence. Dew point and wet bulb are derived on board — useful when you are chasing condensation and mould alongside ventilation. More importantly it computes the two statistics occupational hygiene reports are written around: the 8-hour Time Weighted Average and the 15-minute Short Term Exposure Limit. Six facial icons give an at-a-glance verdict for non-technical occupants, high and low audible alarms flag excursions, and 99 readings can be stored and recalled manually. Supplied with an AC adaptor for continuous desktop monitoring.

• MeasuresCO2 (NDIR), air temperature, humidity
• CalculatesDew point, wet bulb, 8-hr TWA, 15-min STEL
• Displayppm reading + six-icon air quality scale
• AlarmAudible high/low
• Memory99 manually stored readings
• PowerAC adaptor supplied

Bosean BH-90A

Economical Portable Single Gas Detector

The entry point into personal gas detection. The BH-90A is configured for one gas — combustible gas (EX), oxygen, hydrogen sulphide or carbon monoxide — which keeps the cost per person down when a whole team needs cover against a single known hazard. A rechargeable lithium battery gives long standby between charges, the LCD shows concentration alongside instrument status rather than just a bare number, and the anti-slip compound housing survives being dropped down a manhole. Common where the risk profile is well understood: H²S at a wastewater works, CO around generators, oxygen depletion in a cold store.

• ConfigurationSingle gas — EX, O2, H2S or CO
• SensorElectrochemical or catalytic, natural diffusion
• PowerBuilt-in rechargeable lithium battery
• HousingAnti-slip, compact and portable
• Best forTeam-wide cover against one known hazard

Bosean K10

Portable Gas Detector — EX, H2S, CO, O2

The K10 is the ruggedised step up from the BH-90A. It detects combustible gas, hydrogen sulphide, carbon monoxide and oxygen using natural diffusion sampling on high-quality sensor elements, driven by a large-scale integrated circuit with proprietary digital and analogue hybrid communication for stable, repeatable readings. Where it earns its place is the housing: high-strength engineering plastic with a composite non-slip rubber overmould, waterproof, dustproof and explosion-proof. That combination is why it is specified across oil and gas, chemical processing, environmental services, metallurgy, refining, gas transmission and distribution, biochemical pharmaceuticals and agriculture — environments where the instrument takes as much abuse as the operator.

• DetectsEX (combustible), H2S, CO, O2
• SamplingNatural diffusion
• HousingWaterproof, dustproof, explosion-proof
• IndustriesOil, chemical, environmental, metallurgy, gas, agriculture
• Best forHarsh-duty single-operator monitoring

Bosean BH-4A

Portable Multi Gas Detector — 4 gases simultaneously

This is the classic confined space instrument and the practical minimum for entry work. It monitors the four gases that account for most confined space fatalities at the same time: carbon monoxide 0–1000 ppm, combustible gas 0–100% LEL, hydrogen sulphide 0–100 ppm and oxygen 0–30% vol. Oxygen, hydrogen sulphide and carbon monoxide are read on plug-in electrochemical cells; combustible gas on a plug-in catalytic combustion element — plug-in meaning sensors are replaced individually rather than scrapping the instrument. Alarms fire four ways: LCD, LED, audible and vibration, so the warning gets through in a noisy pump station or through a hood and ear defenders. Ex ib IIC T4 Gb certified, with an 1800 mAh battery good for eight hours or more of continuous operation.

• GasesCO 0–1000 ppm · EX 0–100% LEL · H2S 0–100 ppm · O2 0–30% vol
• SensorsPlug-in electrochemical + catalytic combustion
• Accuracy≤±5% F.S. · response ≤30 s
• AlarmsLCD, LED, audible and vibration
• CertificationEx ib IIC T4 Gb
• Battery3.7 V 1800 mAh Li-ion, ≥8 h continuous

Bosean K-40

4-in-1 Multi Gas Detector

The K-40 covers the same four-gas ground as the BH-4A in a different form factor, built on large-scale integrated circuit technology with proprietary digital and analogue hybrid communication. Sampling is by natural diffusion through high-quality sensor elements, giving excellent sensitivity and, more usefully in practice, excellent repeatability — the same atmosphere reads the same way today as it did last month, which is what makes trend data worth keeping. Maintenance is deliberately simple. Where a site already runs BH-4A units, the K-40 is the common alternative when a different display layout or ergonomic suits the crew better.

• Configuration4-in-1 multi gas
• SamplingNatural diffusion
• ElectronicsLarge-scale IC, digital/analogue hybrid comms
• StrengthHigh repeatability, simple maintenance
• Best forRoutine multi-gas safety rounds

Bosean K-600N

6-in-1 Diffusion Multi Gas Detector

Six channels on one instrument, sampled by natural diffusion. The K-600N steps beyond the standard four-gas configuration for sites where the hazard list is longer — adding carbon dioxide and nitrogen dioxide alongside the usual combustible, oxygen, carbon monoxide and hydrogen sulphide set, or substituting other toxics from Bosean's sensor range. A dot-matrix graphical display replaces the segment LCD, so six live readings fit on one screen without cycling, and three-button operation keeps it usable with gloves on. Four alarm modes run in parallel: sound, light, vibration and on-screen. Housed in high-strength engineering plastic with composite non-slip rubber, waterproof, dustproof and explosion-proof.

• Channels6 gases simultaneously
• SamplingNatural diffusion
• DisplayDot-matrix graphical, all readings at once
• ControlsThree-button, glove-friendly
• AlarmsSound, light, vibration, on-screen
• HousingWaterproof, dustproof, explosion-proof

Bosean K-600M

6-in-1 Multi Gas Detector with Sampling Pump

The instrument to specify when the whole point is not entering the space until you know what is in it. An integrated vacuum sampling pump draws the atmosphere out through a line so a manhole, digester, tank or silo can be cleared from outside before anyone descends. Flow is adjustable across six gears from 300 to 800 ml/min to suit line length, and the pump self-alarms if it fails or blocks — a blocked line reading clean air is the failure mode that matters. Six gases are read simultaneously: carbon monoxide 0–1000 ppm, combustible gas 0–100% LEL, hydrogen sulphide 0–100 ppm, oxygen 0–30% vol, carbon dioxide 0–5% vol and nitrogen dioxide 0–20 ppm, with temperature and humidity alongside and a switchable real-time curve view for watching a purge take effect. Records go to a TF card as CSV — up to 100,000 entries, by alarm, fixed interval or manual trigger — and can be printed on site over Bluetooth or tagged by GPS. An optional module adds PM2.5 and PM10 from 0 to 1000 µg/m³. Ex ib IIC T3 Gb, IP65, 4000 mAh battery.

• GasesCO, EX, H2S, O2, CO2, NO2 simultaneously
• PumpBuilt-in, 300–800 ml/min, 6 gears, failure alarm
• LoggingTF card CSV, up to 100,000 records
• ExtrasTemp/RH, live curve view, Bluetooth printing, GPS
• OptionalPM2.5 / PM10 module, 0–1000 µg/m³
• ProtectionEx ib IIC T3 Gb · IP65 · 4000 mAh

Bosean BH-H5

Domestic Combustible Gas Alarm — LP Gas

Portable detectors only protect a space while someone is standing in it. The BH-H5 is the unattended answer: a wall-mounted semiconductor alarm that watches an LP gas installation continuously in homes, guest houses, restaurant kitchens, hotels and apartments. It reads 0 to 20% LEL and alarms at 10% LEL — a tenth of the concentration needed to ignite — with a combined sound and light alarm above 75 dB and a response time under 30 seconds. Two outputs are provided and can act together, including a volt-free normally-open / normally-closed contact set for driving a solenoid shut-off valve or feeding a building alarm panel. Sensor life is around five years in normal conditions, and the design references BS EN 50194:2000. Mounting matters: LP gas is heavier than air, so fit within 0.3 m of the floor and 2 to 4 m horizontally from the appliance, away from windows, draughts, steam and heat.

• GasPropane / LP gas, 0–20% LEL
• Alarm point10% LEL
• AlarmSound + light, ≥75 dB, response ≤30 s
• OutputsActive output + volt-free NO/NC relay contacts
• Sensor life~5 years, semiconductor
• StandardReferenced to BS EN 50194:2000