Gas detection

Gas Detection

Contents The Stuff You Need to Know Calibration Gas Kits Accessories Portable Gas Detectors

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Gas Detection

The Stuff You Need to Know Important Terms Short Term Exposure Limit

Bump or Function Test

Time Weighted Average

This is the maximum concentration of a contaminant a worker can be exposed to in any 15 minute period during the working day.

This is a brief exposure of the gas detector to a known concentration of gas or gas mixture for the purpose of verifying sensor and alarm operation and is not intended to be a measure of the accuracy of the instrument.

This is the maximum concentration of a contaminant a worker can be exposed to over the duration of a shift.

TWA is normally measured over an eight hour shift and is designed to protect the worker from the effects of long-term exposure.

The STEL is designed to protect the worker from long term health effects or situations that may increase the likelihood of accidents.

Calibration Calibration is when the sensors in the gas detector are adjusted to accurately read the same values as a known concentration of gas or gas mixture.

Frequently Asked Questions

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What should I do if my gas detector readings are different to those above?

What are the normal alarm settings on the gas detector?

Unless there are any other toxic gases or hazards present these four gases are generally considered to be the minimum requirement: • Oxygen (O2) – too little oxygen and you cannot breathe or function normally. Too much oxygen could create an explosive atmosphere.

• Combustible Gases (LEL) – the Lower Explosive Limit is the minimum concentration at which a gas will explode. Combustible gases commonly found in a confined space like methane are also an asphyxiant and displace oxygen.

• Hydrogen Sulfide (H2S) – found in regions of geothermal activity. Can also be produced by rotting organic material.

• Carbon Monoxide (CO) – produced by incomplete combustion and is often found when working around vehicles, generators and engines or when conducting ‘hot work’ (such as welding) in confined spaces.

It is important to start your unit in a clean atmosphere before entering a confined space or potentially contaminated area. This is because some gas detectors perform an auto-zero or fresh air calibration on start-up. If the atmosphere is contaminated the unit will automatically adjust the sensors to the conditions and you would potentially not be warned of the unsafe atmosphere.

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How often does my gas detector require calibrating?

At least every six months although some manufacturers suggest every month. Immediately if the instrument fails a bump or function test.

Frequently Asked Questions What should i do if my gas detector readings are different to those above?

I only use my gas detector once a year. Does it still need calibrating every six months?

Ensure that you make your way to a clean atmosphere immediately.

Yes. Regardless of how often it is used it must be within calibration and preferably bump tested before use.

A simple zero or fresh air calibration may need to be performed in the clean atmosphere (as per the manufacturer’s instructions).

Why is it important to bump test a gas detector?

If the problem remains get the gas detector calibration checked by a competent person.

Gas detectors can be adversely affected by airborne substances and high concentrations of gas that exceed their detectable limits.

What are the normal alarm settings on the gas detector?

• O2 – 19.5% Low, 23.5% High • LEL – 5% Low, 1 0% High • H2 S – 10ppm Low, 15ppm High, 10ppm TWA, 15ppm STEL • CO – 25ppm Low, 50ppm High, 25ppm TWA, 200ppm STEL Settings based on the New Zealand Workplace Exposure Standards published by the Department of Labour. Other settings can be used to suit specific site requirements.

Why does my gas detector require calibrating?

A few possible reasons include: 1. The sensors have aged.

2. The gas detector has been started in an unclean atmosphere or the sensors need zeroing.

3. The temperature or humidity has changed since the instrument was last used.

4. The sensors have been exposed to a large concentration of gas.

The bump test will confirm the sensors ability to respond to gas, verify that audible and visual alarms are functioning and ensure it is working correctly between calibrations.

How often does my gas detector require a bump or function test?

All manufacturers recommend bump testing every day before use.

Why does my oxygen sensor need replacing more often than the other sensors?

All oxygen sensors, irrespective of the make and model, need replacement around every two years.

This is because it is reacting to oxygen all the time whether it is on or off and this reaction consumes the material inside the sensor.

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Gas Detection Altair® 5X Multigas Detector Can measure up to six gases simultaneously; when IR unit is used.

• Extended range covering SO2, Cl2, and NH3.

• Superior stability, accuracy, repeatability, fast response and longevity.

• Long-lasting - designed for an average life of more than four years (more than three years for SO2, Cl2, and NH3).

• Faster response/clear times.

• Greater signal stability and repeatability under changing or extreme environmental conditions and are plug-andplay-capable.

• Durability and with large, glovefriendly buttons.

• Option of a glow in the dark housing for all IR sensor equipped instruments.

• MotionAlert™ and InstantAlert™ (Electronic Motion Sensors).

Altair® 4X • MotionAlert™ feature plus audible, visual, and vibrating alarms.

• Most rugged instrument available.

• Altair® 4X Oxygen expected life 5+ years under normal operating conditions.

• Large buttons for easy operation.

• 20-hour battery run time when new.

• NSW Underground Mines Registered.

• Tested to IP67.

• Phosphorescent “Glow” case option.

• Galaxy® GX2 Automated System compatible.

• Global approvals.

• Economically priced.

• MSA Link™ Software-ready.

• QuickCheck™ Test Station available for fast, easy bump testing

Altair® 2X Single Gas Detector Low cost of ownership

• Fastest sensor response times, lowest calibration gas flow rate on the market • 4-year expected instrument & sensor life • 3-year warranty on instrument & most sensors (2 years on Cl2, NH3) • Stand-alone bump tests reduce maintenance, increase productivity (ALTAIR 2XP only) • 1 device can monitor 2 gases (ALTAIR 2XT only) Increased safety awareness & real-time compliance

• Stand-alone bump test anytime, anywhere without specific calibration gas (ALTAIR 2XP only) • Bump pass: green LED flash every 15s, large on-screen checkmark • Bump fail or expiration: red LED flash every 15s, no checkmark • End-of-sensor-life warning and alarm Full-time traceability

• Records 75 alarm events • 150+ hours of periodic data (ALTAIR 2X and 2XP) • 100+ hours of periodic data (ALTAIR 2XT) • Compatible with MSA GALAXY® GX2 Automated Test System and MSA Link Pro software Rugged durability

• Tough over-molded rubber armor • Survives multiple 25-ft drops onto concrete • Agency-certified dust- and water-tight IP67 construction • Intrinsically-safe design

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Altair® Maintenance-Free Single-Gas Detector • 95 dB audible alarm (distinct sounds for High and Low alarms).

• Dual LEDs positioned to be seen from all angles.

• Standard vibrating alarm and standard event logging.

Durability Features

• Hard polycarbonate case, encapsulated in a thick rubberized shell.

• Extremely resistant to drops and impacts.

• Rated to IP67 protection levels for dust/water ingress. Warranty two years or 18 hours of alarm (1080 minutes).

Gas Detection

Altair® Pro Single-Gas Detector Tough rubberized housing.

• One-button operation.

• Accurately measures the gas concentration or percent oxygen.

• Displays information on a large, clear, backlit LCD. • Superior dust and water protection (rated IP67 except O2-R).

• Event-logging and data-logging.

• Excellent impact resistance.

• Versions available for CO, H2S, O2, NH3, Cl2, ClO2, NO2, SO2, HCN and PH3.

• Great RFI performance.

• Adjustable alarm set points are offered for LOW, HIGH, TWA and STEL. • Alarms are indicated by flashing LEDs, an audible alarm, and an internal vibrating alarm.

• Replaceable battery and sensor

Altair® 4X Kit Extreme Glow The kit allows the units to be validated as working (bump tested) as required by the National standards. This is the only way to guarantee an instrument will detect gas accurately and reliably is to test it with a known concentration of gas. Exposing the instrument to a known concentration of test gas will show whether the sensors respond accurately and the instrument alarms properly.

The place in the Gas Detection standard which states bump testing is AS/NZS 60079.29.2 2008 Part 29.2 Gas Detectors - Selection, installation, use and maintenance of detectors 9.2.1 Inspection and field-check (response check).

Calibrations can be completed on your site by users following the manufacturers authorized testing procedure contained in the manuals.

If the instrument fails a bump test, it must be adjusted through a full calibration before it is used.

Calibration Testing Gas MSA offers a complete line of calibration gas cylinders to calibrate all instruments. The gas mixture in calibration gas cylinders is certified to be prepared gravimetrically, using NIST traceable weights. The lot number and nominal value of the gas constituents in volume, percent by mass, PPM, or volume is specified on the cylinder.

Data Logging allows you to keep records of when the units were bump tested, calibrated, and activation of alarms. This information can be printed off and stapled to a confined space permit ensuring correct procedure was followed. These records will help ensure that proper procedures were followed and that safety requirements of the confined space have been properly addressed.

10082834 Jeteye IR Adapter with USB connector

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Gas Detection

Gas Miser™ Demand Regulator No need to manually open or close a valve for accurate calibration once attached to the calibration cylinder. The Gas Miser Regulator is designed for use with pumped instruments and supplies the exact gas flow for the instrument pump. No ON/OFF valve is necessary because the regulator automatically turns itself off when not in use, simplifying the test and calibration process and saving calibration gas

0.25 Litres/Min Fixed Flow Regulators Fixed flow design provides constant and accurate flow to the gas detector.

The .25lpm flow rate ensures that a small amount of gas is released to the instrument which ensures less gas used saving you money.

Altair® GX2 Automated Test System Galaxy GX2 Test System provides simple and intelligent: • Automated bump testing • Automated calibration • Automated data download option • Gas detection fleet management • Suitable for the entire ALTAIR family of portable gas detectors

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