6
Operation and settings
6924-en_V1.3_09/20
79
6.14
What to do when…
This section contains answers to some common questions related to using
the device.
If the stated measures do not remedy the issue, contact Palas or your re-
sponsible representative.
Problem
Explanation/action
Testing routine
Breath Re-
sistance
: The differential
pressure measured is higher
that the reference value (mask
data sheet).
The differential pressure measured can only be compared if the measure-
ment conditions are the same. Compare flow rate, face area and face ve-
locity and convert the values if necessary.
Formula for calculating face velocity W [m/s]:
W = Q / A
Q = flow rate [m
3
/s], A = face area [m
2
]
The mask was clamped into the adapter such that a significant part of the
surface is clamped in the adapter and air cannot flow through it.
Clamp the mask such that as much surface as possible protrudes beyond
the adapter but that the mask is clamped securely.
The penetration value mea-
sured is higher that the refer-
ence value (mask data sheet).
The mask was not clamped securely in the adapter. Clamp the mask in the
adapter such that it is secure but that as much surface as possible pro-
trudes beyond the adapter.
The dilution system is clogged, so large particles are being held back.
Modify the dilution system and clean it with compressed air.
The mass concentration
up-
stream mass
has dropped
significantly.
The dilution system is clogged, so large particles are being held back.
Modify the dilution system and clean it with compressed air.