Gas Monitor Bump/Function Tests

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How do you know if the equipment is working correctly?

Portable gas monitors are vital early warning devices for maintaining the safety of personnel working in contaminated atmospheres.

There have been cases where a fault has prevented the atmosphere from interacting with the sensors, leading to the unit not detecting the change. In one case, a worker was overcome by lack of oxygen in an atmosphere heavily contaminated by nitrogen. Fortunately, there was a rescue plan in place and after being resuscitated. That worker lived to work another day.

Altair 4XRMost manufacturers and relevant Australian Standards recommend regular calibration with certified test gases, in most cases, at set intervals, at least every six months.

Service may be required more often if the application is  particularly aggressive or in the case of exposure to consistently high concentrations. 

Manufacturers recommend re-calibration & service if a unit fails a bump/function test.

Other environmental factors including air pressure, temperature and humidity can also affect the accuracy of the unit. Completing a daily 'Fresh Air' or 'Zero Sensors' calibration 'tunes in' the sensors to todays conditions and is one part of the daily "before use" test requirement.


Why Challenge Test? (Function or Bump Testing)

Gas detection manufacturers, standards and code of practice documents (AS/NZS2865/61779) recommend that all instruments are function or bump tested using a certified gas mixture prior to operation.Altair 2x

A 'bump" or "challenge" test of your gas detector will determine whether the unit is fit for use.

Not only does the bump/challenge test verify the unit will respond to gas, it also confirms that the detectors audio and visual alarms are in working order.

This means that when a worker is out in the field, they will be able to hear / feel / see when your detector goes into alarm if/when exposed to gas.


How Often Do I Need To Bump Test? 

IMG 0687Examples of legislative requirements.

“Gas monitors used for the purpose of atmospheric monitoring within a confined space should be maintained and used in accordance with manufacturer’s instructions and warnings and in reference to AS/NZS 60079”: AS 2865:2009 Confined Space Safe Work Australia Exposure Standards

"It is recommended that this is done by personnel actually operating the apparatus and is strongly recommended that it is performed before each day of use”: AS/NZ 60079.29.2:2016 Selection, installation, use and maintenance of detectors

 “Any atmospheric testing and monitoring in a confined space should be carried out by a competent person using a suitable, correctly calibrated gas detector”: Safe Work Australia: Code of Practice Confined Spaces]


What Does My Manufacturer Recommend?

Below are a sample of just a few manufacturers currently in the Australian market. This represents the message from all manufacturers. Check your specific manufacturer in relation to your unit.

BW LOGO BLACK WHITE"As stated in BW Technologies multi-gas detector manuals, to verify that your detector is responding to gas, BW recommends bump testing the sensors before each day’s use. The bump test exposes the detector to a gas concentration that exceeds the alarm set-points to confirm the sensor’s ability to respond. Manually verify that the audible and visual alarms are activated. Calibrate if the readings are not within the specified limits. Taking less than a minute, a functional (bump) test is easy to perform and will ensure that the gas detector is responding and the gas path is not blocked."

MSA"Perform a bump test and calibration check every single day before anyone uses the DRPGM that day (and according to manufacturer’s instructions)". More info

Drager Logo"Regular equipment testing can save lives. Calibration evaluates the response of gas detectors against standards and adjusts the devices to optimise accuracy. It normally involves zero point and span point tests and adjustments at fixed intervals. Bump tests check that gas detectors are functioning as they should. These should be performed before every use – and if they indicate a fail, the instrument must be submitted for calibration prior to use" More Info

crowcon"While it is strongly recommended by manufacturers, from the 1st November 2010, EN60079-29 part 1 has been harmonised under the ATEX directive 94/9/EC.  Therefore to comply with the ATEX directive, portable apparatus sensing flammable gases should have a functional check with gas before each day of use." More Info


Keeping Accurate Records

It’s essential that you keep records of all device testing and maintenance.

pemitShould a user experience a reportable event with one of your devices, the local safety regulator will need to see a history of all bumps and calibrations, most likely for the lifetime of the device. But even without an incident, testing and maintenance data can track other valuable information, and new technology makes record-keeping easier and more valuable than ever.

Digital tracking and remote monitoring are just some newer technologies that automatically track and allow you to manage your fleet’s bump tests and calibrations from wherever you are.

Some of the latest devices can even be paired with GPS devices or have sim cards installed so that you always know where your workers are.

If you detect that they’ve been exposed or if a man-down alarm indicates that a worker experienced a health emergency, you know exactly where to send help—and what kind of help to send.


How long does a Bump Test take?

On some units, manually, a bump/challenge test will take between 3-5 minutes for the sensors to respond fully and activate the alarms. Typically with this style of bump test, it requires a written record of testing to support.

Some manufacturers (MSA 4X/5X) as little 10-15 seconds. But these units have datalogging which means the unit records the test which can be downloaded later or uploaded via a calibration dock automatically.

Some units, even with a calibration dock can take 2-3 minutes (BW) and still require a written record to be maintained.

What do I need to bump test my portable gas detector?

Manual Calibration

  • Gas Cylinder(s) with mix to suit detector
  • Fixed Flow Regulator (DFR for pump module)
  • Calibration Cup to suit detector
  • Tubing

Automated via a Calibration Dock

  • Calibration Dock to suit gas detector
  • Gas Cylinder with mix to suit detector
  • DFR Regulator
  • Tubing
What else should I consider when challenge testing my portable gas detector?

Complete an external check of your detector by checking the:

  • sensor filters - are not blocked with dirt, mud, chemicals or any other foreigh substance that will impede the sensors from responding to gases in the atmosphere
  • external housing - missing screws and cracks in the houseing or LCD screen
  • missing parts - clothes clip, compliance/certification sticker

These might not seem like much but they can influence the integrity of your unit.  

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