TE-WILBUR OPERATIONS MANUAL REV 002.15 06/11/2015
Tisch Environmental 1-TSP-AND-PM10 firstname.lastname@example.org www.tisch-env.com Page 42 of 183
Weigh each filter on the microbalance. Follow the microbalance
manufacturer’s operations manual for proper operation of the microbalance.
The filters should be handled with forceps and only held by the support ring.
Pass the filter, support ring side up near an antistatic strip for 60 seconds
before weighing. Immediately transfer the filter to the microbalance for
weighing. Record the filter ID, lot number and tare-weight (pre-weight).
After every 10 filters, reweigh one of the standards and record the data. These
standards should be within 3µg. Also reweigh one of the 10 filters. It must be
within 15µg of its original weight.
After all the filters are weighed, both working standards should be reweighed
and must be within 3µg of their standard. Also one random filter of the total
should be reweighed and it must be within 15µg of its original weight.
4.11 Calculating Mass Concentrations
The total sample volume can be calculated from the sample which is located
on the sample completed screen. If the total volume is not available it can be
calculated using the following formula:
= total sample volume (m3)
= average sample flow rate (Lpm)
= total sample time (hours)
= conversion to m3/hr
Using the pre and post sample filter weights, the total filter mass gain can be
found by the following formula:
Where: Mdelta = total mass gained during sampling in µg
Mpost = post sample weight in µg
Mpre = pre sample weight in µg