Calibration - Slope And Offset; Measurement Algorithm - Teledyne 300E Instruction Manual

THEORY OF OPERATION

10.5.2. Calibration - Slope and Offset

Calibration of the analyzer is performed exclusively in software.
During instrument calibration (see Sections 7 and 8) the user enters expected
values for Zero and Span via the Front Panel Keypad and commands the instrument
to make readings of calibrated sample gases for both levels. The readings taken
are adjusted linearized, and compared to the expected values, With this information
the software computes values for instrument slope and offset and stores these
values in memory for use in calculating the CO Concentration of the sample gas.
The Instrument slope and offset values recorded during the last calibration can be
viewed by pressing the following keystroke sequence:

10.5.3. Measurement Algorithm

Once the IR Photo-Detector is signal is demodulated into CO MEAS and CO REF by
the Sync/Demod Board and converted to digital data by the Mother Board the
M300E analytical software calculates the ratio between CO MEAS and CO REF. this
value is compared to a look-up table is used, with interpolation, to linearize the
response of the instrument. The linearized concentration value is combined with
calibration slope and offset values, then normalized for changes in sample gas
pressure to produce the final CO concentration. This is the value that is displayed
on the instrument Front Panel Display and is stored in memory by the analyzer's
iDAS system.
184
SAMPLE RANGE = 50.0 MGM
< TST TST > CAL
SAMPLE TIME = 16:23:34
< TST
TST > CAL
SAMPLE OFFSET = 0.000
< TST TST > CAL
SAMPLE SLOPE = 1.000
< TST
TST > CAL
Model 300E Carbon Monoxide Analyzer
CO =XX.XX
SETUP
CO =XX.XX
SETUP
CO =XX.XX
SETUP
CO =XX.XX
SETUP
Instruction Manual
P/N 04288 Rev: A