Monthly Archives: January 2014

Protecta Pro 1340125 Shock Absorbing Lanyard

Shock Absorbing Lanyard Limitations

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There is an all too common situation where a shock absorbing fall protection lanyard does not meet fall protection requirements.

Protecta Pro 1340125 Shock Absorbing Lanyard    Miller T5111 Shock Absorbing Lanyard

Miller Fall Protection puts it like this, “when using a shock absorbing lanyard, it is important to understand how to calculate potential fall distance to avoid contact with a lower level“. A lower level can be the decking of a lower floor, an obstruction below you or even the ground.

Whenever the distance from your anchor point to that lower level is less than 18.5 feet a shock absorbing fall protection lanyard cannot be used. Take a look at Miller’s diagram below to see why.

miller-free-fall-diagram

Miller explains the above diagram as follows:

  1. When using a six foot shock absorbing lanyard and a full-body harness, first add the length of the shock-absorbing lanyard [6 ft.] to the maximum elongation of the shock absorber during deceleration [3-1/2 ft.] to the average height of a worker [6 ft.].
  2. Then, add a safety factor of 3 ft. to allow for the possibility of an improperly fit harness, a taller than average worker and/or a miscalculation of distance. 
  3. The total, 18-1/2 ft., is the suggested safe fall clearance distance, the height at which you must attach to an anchorage to minimize the risk of contact with a lower level.

This means that if a shock absorbing lanyard is used below 18.5 feet, the “lower level” will be struck in the event of a fall. This problem is easily solved.

Shock Absorbing Lanyard Alternatives

A shorter shock absorbing lanyard will provide a few more feet of leeway (like the below 3′ lanyard). However, it also greatly limits the room a worker has to operate. In most cases, a shorter lanyard will not be possible.

Gemtor 3 Foot Shock Absorbing Lanyard

The best way to solve this problem is to use a self retracting lifeline. Most self retracting lifelines decelerate much sooner than a shock absorbing lanyard’s 3.5′ deceleration. This reduces potential fall distance.

Unlike a shock absorbing lanyard, a self retracting lifeline contains no slack. Depending on where the SRL is mounted, this factor can also reduce potential fall distance.

Please note, however, that the potential fall distance will still need to be calculated when using a self retracting lifeline.

DBI Sala Self Retracting Lifeline    miller-scorpion-fall-limiter

Downloads:

All the pics are linked to products at Major Safety. There you can get additional info, purchase, or contact us with more questions. We are happy to help.

by Corby Amos

GX-2009 Gas Monitor Calibration

Gas Monitor Calibration – What, Why, How Often

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What does it mean to calibrate a gas monitor? Why is calibration even necessary? How often is calibration to be performed?

GX-2009 Gas Monitor Calibration

Gas Monitor Calibration

A gas monitor calibration determines if a sensor can accurately read the known concentration of a calibration gas. If it can’t, the calibration electronically adjusts the gas monitor to account for the difference. Simply put, a calibration aligns a sensor with a calibration gas.

Calibration Drift

Calibration is needed because of Calibration Drift. Calibration Drift occurs when the sensor can’t accurately read the calibration gas.

A number of factors cause Calibration Drift in gas monitors (from OSHA):

  • AGE – Gradual chemical degradation of sensors and drift in electronic components that occur naturally over time.
  • ENVIRONMENT – Chronic exposures to, and use in, extreme environmental conditions, such as high/low temperature and humidity, and high levels of airborne particulates.
  • SENSOR POISONING – Exposure to high (over-range) concentrations of the target gases and vapors. 
  • MONITOR ABUSE – Harsh storage and operating conditions, such as when an instrument is dropped onto a hard surface or submerged in liquid. Normal handling/jostling of the equipment can create enough vibration or shock over time to affect electronic components and circuitry.

When a sensor can no longer be aligned to the calibration gas during calibration, a sensor failure occurs. This failure is due to calibration drift. The sensor will need to be replaced.

Calibration Frequency

OSHA does not give any detailed recommendation concerning gas monitor calibration frequency. OSHA simply says, “follow the manufacturer’s recommendations with regard to calibrating the instruments.”

RKI Instruments, in a effort to be helpful, outlines two extremes of calibration frequency:

  • Example 1 – Users who require the readings to hold up in court as data for certain legal applications must calibrate both before and after each test or each series of tests, in order to remove all doubt of the proper functioning of the instrument.
  • Example 2 – The other extreme is someone who only uses the instrument a couple times a year for non-critical applications. This type of user should calibrate their instrument before each use.

Most users will be in the middle of these two extremes. RKI, for example concludes that “typical calibration frequencies for most applications are between 3 and 6 months, but can be required more often or less often based on your usage”.

Calibration Frequency is ultimately determined by the end user based on OSHA’s requirement to follow the manufacturer’s guidelines. Neither the manufacturer nor a distributor can make a specific recommendation.

Helpful Downloads

Please visit Major Safety’s Gas Monitor Service Center for more help.

by Corby Amos