Conversion of ppm readings to other units (mg/m3)
All of ION Sciences PID based instruments give reading in PPM as standard, but sometimes other units are required. A conversion factor based on the molecular weight, the temperature and pressure where the measurement is taken is used, so every measurement taken will have a slightly different conversion factor.
Converting reading units
Different regulation bodies use different types of units for different types of Workplace Exposure Limits (WELs). Parts Per Million (PPM) is used when a substance exists as a gas a vapour at standard atmospheric conditions where as mg/m3 is more commonly used for compounds that do not form vapours at standard atmospheric conditions, however gases and vapours can be expressed in both, as well a percentage (%)
PPM into mg/m3
Within the personal and portable Instrument sold by ION Science these calculations are done within the instrument software so no manual calculations are needed to convert the units. However the fixed units only display in PPM so occasionally a manual calculation is needed, these calculations are displayed below to show how convert from ppm to mg/m3, and back again. The 2 numbers in the equations are based on standard conditions of 25 °C and sea-level atmospheric pressure of 1 atmosphere.
PPM to Percentage %
The conversion from PPM to percentage and back again is slightly simpler, we may need to use these calculations when deciding what calibration gas to use, say we have a 1.2 % bottle of Isobutylene which we want to calibrate on our instrument on, if we want to know what this would be in ppm the below calculation would be used:
ppm = % X 10,000
ppm = 1.2% X 10,000 = 12,000 ppm
For further information, Please email email@example.com or telephone: +44 (0) 1763 208 503 as we will endeavour to assist you with further details.
White Paper Article
Everything you need to know about Conversion of ppm readings to other units (mg/m3)
Our White Paper Article is available to download below, the information provides you with key information regarding how different regulation bodies use different types of units for different types of Workplace Exposure Limits (WELs). We outline the current reading that is available within our instruments and calculations on how to convert from ppm to mg/m3, and back again.
Download your copy of ‘Conversion of ppm readings to other units (mg/m3)’
Please complete the form below to download the White Paper Article.