Safety App Of The Week

February 17, 2014 No Comments

Below is this week’s “Safety App of the Week“.  Every Monday we publish an article that reviews and rates a new workplace safety app.  Our testing is done on Apple iPads and Samsung Galaxy Tab 3s.  We rate each app from to ♥♥♥♥♥ (♥♥♥♥♥ is the best).  Prior app of the week articles are archived here.


Official Description  

“This App is a full featured sound level meter, designed by a signal processing expert. It is iPhone/iPod/iPad compatible and adapts itself to the actual screen resolutions (“HD”, “retina”).  It consists in two parts: half top for basic features, half bottom for advanced ones (L95, %D).

Half top was thus designed to be extremely easy to use.  Only two settings are requested:

* select ‘fast’ or ‘slow’ update rate, which corresponds to 2 different integration periods
* select the type of weighting: A or C or Z (Z meaning roughly: no filtering)
These settings are saved when exiting the App

Some tips for weighting:

* select A to evaluate the feeling of a person against a noise
* select Z to balance an audio system

Supports upside-down orientation.

The min and max values are monitored and displayed in green in the upper view. An average value (Leq, LAeq, …) is computed on top of this: the green triangle.  Take care that this latter corresponds to the logarithm of the average power and not to the average of logarithm values, which is completely different.  Integration time for this average value is: all time since start-up of the App or last reset.  To reset these extreme and average values, touch the text named RESET.

Bottom view is used to display an historical curve. A grid is visible, with lines every 10dB vertical and 10s horizontal.

Half bottom now:

* a real-time histogram is displayed on left side
* it can compute L%: L95, L50, …
* it can make some dosemetering: for this you need to set threshold, criterion and exchange values. This is for advanced users due to the complexity of underlying concepts

As for all sound-meter (at any price, hardware or software), you should calibrate it against a reference in order to achieve best accuracy.  For this you have a rotary knob to add or remove a fixed offset to the measured values.1

Thumbs Up

  • produced by the developer of SPLnFFT (our #1 rated noise measurement app)
  • logSPL costs $1.99 – that’s $2.00 cheaper then it’s big brother SPLnFFT 
  • logSPL is simpler and easier to use than SPLnFFT
  • logSPL likely uses the same sound analysis engine as SPLnFFT
  • we tested log SPL against SPLnFFT on an iPad V4 and found the results to be similar (see below)
  • you can dialog directly with the developer
  • logSPL is the new “lite” version of the SPLnFFT app

Thumbs Down

  • an operating manual (or at least FAQ page) would be nice
  • less functionality then the SPLnFFT app, but sufficient for the needs of most safety professionals
  • we doubt an Android version of either logSPL or SPLnFFT will ever be developed because of the wide variety of Android mobile devices
  • we will keep using the SPLnFFT app because it allows us to email the results of our noise tests – the logSPL app does not have the ability to email its’ results

Testing Results  (all units are in dBA)

  • low frequency –             min + .3   leq -.3   max -.2 
  • medium frequency –      min + .4   leq -.1   max +.4
  • high frequency –           min + .3   leq +.5   max +.5

Overall Rating

  • iPad / iPhone 5 –  ♥♥♥♥
  • not available for Android

¹ Descriptions courtesy of Apple Inc.

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