Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
RPSTAT and RPPIPER for each of the OPC's size channels. RP is the ratio of particle mass concentration while PIPER was moving to number concentration during the reference period (Equations 1 and 2). There were 43 homes with carpet and 22 homes with bare floor in the room that was sampled.
