YOKOGAWA FC400G, User Manual, Page: 65 / 91

< 7. Calibration >
7-4
IM 12F5A1-01E
NOTE
(1) During Auto calibration, if the
MODE
key or
＊
key are pressed then Auto calibration is
aborted, and immediately the analog output hold is released, <HOLD> and <CAL> go OFF, and
the <MAINT> contact output goes OFF. The calibration interval timer is reset to zero.
(2) When the following conditions are true, the calibration interval timer starts to count from 0 to its
“count up” setting.
• When the unit was started up with Auto zero calibration turned ON.
• When Auto zero calibration is turned ON.
• After the Auto zero calibration interval is changed (provided Auto zero calibration is turned ON).
• When the Wash / Auto zero calibration setting is switched to Auto zero calibration.
(3) The counter timer keeps running regardless of operation mode.
(4) Auto zero calibration is initiated only in MEAS mode. If the counter reaches its “count up” setting
while the instrument is in MAINT mode, calibration is cancelled - not triggered - that time : the
timer is reset and counting restarts.
T7.2.3E.ai
*Wash/Auto zero
calibration contact
output *1
Output hold and
Maint contact
T1 : Auto zero calibration interval T2 : Auto zero calibration setup time
T3 : Auto zero calibration time : varies depending on conditions T4 : Auto zero stabilization (settling) time
of sets stability determination parameter.
*1 WASH/CAL lamp blinks (5.2 Display Content on the Display Unit

) and W1, W2 of Figure 3.4 are operated.
T1
T1
T1
T2 T3* T4
T2 T3* T4
OFF OFF
OFF
ON ON
OFF OFF OFF
ON
ON
l
Zero filter flushing
Under the following condition, zero filter flushing function will be activated automatically.
1) Wash / Auto zero calibration set to Auto zero calibration,
2) Auto zero calibration timer turned ON, and
3) Auto zero calibration interval set to one day or longer.
l
Zero filter flushing interval and sequence
Interval is fixed, once in 24 hours.
When flushing starts, analog output is held, <HOLD> lights, <FLUSH> flashes, and the <MAINT>
contact turns ON. During Auto zero calibration setup time, “zero” water flows then - after the
stabilization (settling) time - it reverts to sample water.
Finally analog output hold, <HOLD> display, and <FLUSH> display revert to normal, and <MAINT>
contact output turns OFF.
Zero filter flushing interval timer is started and stopped as follows:
Timer is started when: