YOKOGAWA EXAxt ZR402G, User Manual

Page: 112 / 169

<9. Calibration>
9-5
IM 11M12A01-04E 11th Edition : Jul. 19, 2017-00
21.0 p1 p2 0.51
81.92
ez
e2
e1
es
0
C
A B
Zero correction ratio = (B/A) x 100 (%) Correctable range: 100 ± 30%
Span correction ratio = (C/A) x 100 (%) Correctable range: 0 ± 18%
Cell
electromotive
force, mV
Calibration curve
before correction
Corrected calibration
curve (theoretical
calibration curve)
Zero origin
Span gas concentration
Zero gas concentration
Span origin
Oxygen concentration (vol%O
2
)
F9.2E.ai
Figure 9.5 Calculation of a Two-point Calibration Curve and Correction Ratios Using
Zero and Span Gases
Figure 9.6 shows a one-point calibration using only a span gas. In this case, only the cell
electromotive force for a span gas with oxygen concentration p1 is measured. The cell
electromotive force for the zero gas is carried over from a previous measurement to obtain the
calibration curve. The principle of calibration using only a span gas also applies to the one-point
calibration method using a zero gas only.
21.0 p1 0.51
81.92
ez
e1
es
0
C
A B
Zero correction ratio = (B/A) x 100 (%) Correctable range: 100 ± 30%
Span correction ratio = (C/A) x 100 (%) Correctable range: 0 ± 18%
Cell
electromotive
force, mV
Calibration curve before
correction
Previous
zero gas data
Corrected calibration curve
(theoretical calibration curve)
Zero origin
Span origin
Span gas concentration
Oxygen concentration (vol%O
2
)
F9.3E.ai
Figure 9.6 Calculation of a One-point Calibration Curve and Correction Ratios Using a Span Gas
9.1.5 Characteristic Data from a Sensor Measured During
Calibration
During calibration, calibration data and sensor status data (listed below) are acquired. However,
if the calibration is not properly conducted (an error occurs in automatic or semi-automatic
calibration), these data are not collected in the current calibration.
These data can be observed using parameter codes “A20” to “A22”, and “A50” to “A79”. For
an explanation and the operating procedures of individual data, consult Section 10.1, “Detailed
Display.”
(1) Record of span correction ratio
Recorded the past ten span correction ratios.
(2) Record of zero correction ratio
Recorded the past ten zero correction ratios.