SE-RDA User Instructions 100507-03 B
Copyright © 2021 The S.E.A. Group
5
Precalibrated filter set
Each precalibrated filter set (supplied separately) consists of a P3 particulate filter or a
combination gas/particulate filter, including prefilter. The precalibrated filter sets are real
filters approved for use with the Sundström SR100 and SR200 respirators.
The air flow resistance characteristic of each filter set has been accurately measured in
the factory. The flow parameters Aneg and Bneg are marked on each filter set. The SE-
RDA software uses these parameters to convert the recorded mask pressure data to
inhalation flow.
Important
Each filter set may be used for a single shift only. The prefilter must always be
fitted during use. Using the SE-RDA without the prefilter will invalidate the filter
calibration and cause inaccurate flow rate measurement. Do not disassemble the
filter sets, or replace a filter in the set. If the filters are tampered with or
damaged, the filter parameters may no longer be valid.
SR100/200 adapter with pressure tube
The SE-RDA is supplied with an adapter which is suitable only for Sundström SR100 and
SR200 respirators. The adapter connects the breathing zone of the respirator to the
MASK port on the SE-RDA unit.
Each SR100/200 adapter is supplied precalibrated. It is marked with a serial number and
two filter parameters, Apos and Bpos. During exhalation, the SE-RDA logs the pressure
drop across the exhalation valve. The parameters are used to convert the pressure drop
to exhalation flow rate.
Important
Do not disassemble or tamper with the SR100/200 adapter. Doing so may
invalidate the parameters, resulting in inaccurate flow rate results.
Note: The exhalation valve has lower air resistance and less predictable air/flow
characteristic than the filters, therefore the accuracy of exhalation flow measurement will
typically be lower than for inhalation, especially at lower breathing rates.
SR100 and SR200 respirators
Any Sundström SR100 half-mask or SR200 full-face respirator may be used with the SE-
RDA, provided it is properly maintained, in good working order and used in accordance
with the user instructions.
Warning
The SR100/200 adapter’s pressure tube must be connected to the SE-RDA MASK
port AT ALL TIMES during use of the respirator. If the pressure tube is open to
the air it will provide a direct leakage path from the environment into the
breathing zone, resulting in reduced or no breathing protection.
