The iso-kinetic probe should be used for most sampling applications.
When taking a sample of typical indoor or outdoor aerosols the opening of the isokinetic
probe should always face upward. The AEROCET 531 can be held in your hand
or placed on a flat surface with its display facing towards you.
When sampling in an area that has a constant airflow, such as a clean room, duct, vent
or the downstream side of a filter, always align the opening of the iso-kinetic probe to
the air movement.
The length of the Tygon tubing going from the inlet of the AEROCET 531 to the isokinetic
probe can be increased if necessary. However, longer lengths can burden the
pump and slow the sample flow rate or cause premature pump failures. Also, count
losses, especially for larger particles, will increase. Met One Instruments recommends
to keep the tubing length as short as possible. The tubing length should never exceed
four feet.
The sampling height will affect the AEROCET 531 reading. Taking a sample near the
floor can give results several times higher than a sample taken at eye level.
When using the AEROCET 531 to analyze a contamination problem be aware that not
all contamination problems are continuous, some are the result of a short-term event or
burst of particles. Locating the source will require taking a number of samples in the
same area. It may be necessary to connect the AEROCET 531 to a computer and log
data over 24 hours to detect a fast contamination event.
3.7 G3120 Relative Humidity/Temperature Sensor
Relative Humidity and Temperature measurements may be added to the AEROCET
531 at any time by plugging in the G3120 Relative Humidity/Temperature Sensor into
the plug on the top of the unit.
The screen will now include actual readings of both measurements; data will now
include the measurements in each data record.
3.8 G3115 Printer
Printed records may be added to the AEROCET 531 at any time by plugging in the
optional G3115 printer. This printer is a complete 40 character wide portable printer with
an internal battery and an external AC adapter/charger.