Endress+Hauser SpectraSensors SS2000e, Operator'S Manual

Page: 50 / 114

NS 5.14 Firmware
2
–
36 4900002262 rev. B 3-23-21
The value of the RATA Multiplier parameter,
S
, is determined by
,
where
C
1
is the certified concentration of standard No. 1,
C
2
is the certified
concentration of standard No. 2,
A
1
is the measured concentration (analyzer
reading) of standard No. 1 without any RATA adjustment, and
A
2
is the
measured concentration (analyzer reading) of standard No. 2 without any RATA
adjustment.
The
RATA Offset parameter,
O
, is determined by
,
where
S
can be
1
when a sample from only one concentration standard is
available.
For a non-zero single concentration standard RATA Multiplier parameter,
S
is
determined by
where O can be zero, if desired.
After an automatic, semi-automatic, manual Mode 7 or manual Mode 8
validation completes, the analyzer automatically calculates new RATA
Multiplier and RATA Offset values. These values are based on the number of
validations that the analyzer is configured to accept and the type of validation
used.
To perform this calculation, the most recent validation result(s) will be used.
These calculations are based on the average measurement values during the
validation, which can be viewed from the Mode 9 display. These values are not
constrained by the measurement range of the analyzer, which will ensure
accurate RATA Multiplier and RATA Offset values are calculated.
To perform the calculation
If RATA is enabled, the current RATA Multiplier and RATA Offset values must
be removed from the measured Validation 1 and/or Validation 2 concentration
values. Depending on the number of validations, or the validation type, one of
the following scenarios occur:
•
If using a non-permeation single validation system with a zero gas as
the standard, then a new RATA Offset is calculated leaving the
RATA Multiplier at its previous value.
•
If using a non-permeation single validation system with a non-zero
gas as the standard, then a new RATA Multiplier is calculated
leaving the RATA Offset at its previous value.
S
C
2
C
1
–
A
2
A
1
–
-------------------- =
O C
1
S A
1
  
– =
S = (C
1
- O) / A
1