Gravimetric determination of the inhalable dust fraction (E-dust) according to IFA 7284

Sampling

The following sampling systems are available at the GSA for the sampling of E-dust:

• SG10-2 with GSP3.5 (personal sampling)   
• SG5100 ex with GSP3.5 (personal sampling)   
• PM4-2 with total dust head (stationary sampling)
• VC25-2 with total dust head (stationary sampling) 

Personal sampling is usually performed with a GSA measuring device, the SG10-2 and GSP3.5 or with SG5100 ex with GSP3.5.

The air loaded with dust is sucked in with a battery-operated pump (SG-10-2) with a volume flow of 3.5 l/min (210 l/h). We recommend a measurement duration of 2 h to reach a volume of
0.42 m³ to be able to detect 1/10 of the limit value (10 mg/m³). The air loaded with E-dust flows through a membrane filter. This is a binder-free glass fibre filter with 37 mm diameter, on which the dust is separated.

Site-specific sampling is carried out by means of a volume flow-controlled sampling device with IFA E-dust sampling system (PM4-2) with a volume flow of 4 m³/h or with IFA E-dust sampling system (VC25-2) with a volume flow of 22.5 m³/h. The sampling is carried out by means of a volume flow-controlled sampling device with IFA E-dust sampling system (PM4-2) with a volume flow of 4 m³/h or with IFA E-dust sampling system (VC25-2) with a volume flow of 22.5 m³/h. We recommend a measurement duration of 2 h.

As filter medium, a binder-free glass fibre filter with a diameter of 70 mm or a binder-free glass fibre filter with a diameter of 150 mm weighed under defined conditions (temperature and humidity) is used.

Analysis

• Electronic analytical balance Mettler Toledo XPR 105 with ionisation module 
• Hydrothermograph (Testo/ testo Saveris 2)

Preparation of the filters

The empty weight of the filters must be determined before sampling.

The filters are laid out for 48 hours in the weighing area at a relative humidity of 40 % – 55 % and a temperature of 22 °C – 28 °C. This storage is called conditioning. After conditioning, the filters are weighed and the results are recorded.

Analytical determination

The loaded filters are laid out for 48 hours in the weighing area (at a relative humidity of 40 % – 55 % and a temperature of 22 °C – 28 °C. After conditioning, the filters are weighed. The blind filters are to be treated in the same manner.

The mass of the E-dust is determined by differential weighing, weighing of the conditioned filters before and after sampling.

The determination limit for the 37 mm diameter binder-free glass fibre filter is 0.1 mg. For the
70 mm diameter with binder-free glass fibre filter is 0.2 mg and for a 150 mm diameter binder-free glass fibre filter is 0.3 mg absolute.

Limit value

The workplace limit value according to TRGS 900 for the respirable fraction (E-dust) is 10 mg/m³.