MBV MAS-100 Regulus - Annex a - Procedural Background Information; MAS-100 Ex; MAS-100 Iso

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User Manual MAS-100 Regulus en.docx, Version: 4.0
ANNEX A – PROCEDURAL BACKGROUND
INFORMATION
A.1 MAS-100 / MAS-100 EX / MAS-100 ISO
This chapter provides general information about the adjustment and calibration procedures
of the legacy air samplers MAS-100, MAS-100 Ex and MAS-100 Iso.
A.1.1 General description of adjustment and calibration
The air samplers MAS-100, MAS-100 Ex and MAS-100 Iso operate with a 400 × 0.7 mm per-
forated lid. The calibration of the volume flow rate requires adjustment of a single critical
flow point, the K
3
value. Following the calibration, a load adjustment is made to the fan mo-
tor, giving the K
5
setting. The MAS-100with firmware V2.6x and above allows the adjust-
ment of both values, K
3
and K
5
. The MAS-100 Iso with firmware V2.81 in CU-units and V2.51
in AU-units and above allows the adjustment of both values, K
3
and K
5
.
A.1.2 K
3
air volume flow rate adjustment
The K
3
value is a direct adjustment made to the mass flow sensor in the MAS-100,
MAS-100 Ex and MAS-100 Iso. The adjustment range for the K
3
value is between 0 and 200.
The mass flow sensor controls the air flow rate of the air samplers critical air flow adjust-
ment point. The sensor is part of a loop that includes the fan and power supply. The mass
flow sensor continuously regulates the speed of the fan proportional to the mass of the air
passing through it. An accurate volumetric flow measurement is made with the anemome-
ter under normal operating conditions. This volumetric flow rate is converted to mass flow
and the K
3
is then adjusted to give a flow rate within the specified tolerances of
100 SLPM ±2.5 %. The flow sensor will then maintain the dynamic conditions to produce an
air flow rate within the specified tolerance. The total uncertainty for the MAS-100,
MAS-100 Ex and MAS-100 Iso calibration is ±2.5 %.
Note
The K
3
set point is the only critical flow parameter in the adjustment process
on the MAS-100, MAS-100 Ex and MAS-100 Iso
A.1.3 K
5
fan motor load adjustment
The K
5
adjustment optimizes the voltage delivered to the motor, in order to maintain con-
sistent flow rates while using a flow restriction. This was necessary at the introduction of
the resistance-free anemometer DA-100, to be able to compare the readings with the old
and discontinued anemometer MAS-100 CU.
Note
This parameter is no longer needed for adjustments with the anemometers
DA-100, DA-100 NT or MAS-100 Regulus.
Therefore it must be set to 0.