Riken Keiki EC-6002, Operating Manual

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6 Operations and Functions 6-4. Other functions
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RM-6000
6-4. Other functions
<Suppression Function>
Some types of detector heads connected to the indicator/alarm unit are influenced by environmental
changes (temperature, humidity, and other characteristics) or interference gases (interference
characteristics) in no small measure, which affects the reading.
Therefore, the reading might fluctuate around zero even in a normal state with no gas leakage.
This function obscures influences by environmental changes and interference gases around zero that have
no meaning for your management rules of gas alarm. This function is used to hide (suppress) the fluctuation
of the reading under the setting value, indicating zero.
<<Example: CH4 0 - 100% LEL Specifications>>
NOTE

In the maintenance mode, this function is disabled and the fluctuation of the reading under the setting
value is displayed.

When a sensor unit with the oxygen deficiency alarm (O2: 0 - 25 vol%) is equipped, the zero
suppression is shifted to AIR suppression (20.9 vol%) automatically. That is, a small variation of the
reading around 20.9 vol% is displayed as 20.9 vol%.
<Zero Follower Function>
Some types of detector heads connected to the indicator/alarm unit might have sensitivity variations after
being used for a long period.
This function corrects the fluctuation of the reading at the zero point (zero drift) among the sensitivity
variations over time by a program manipulation to stabilize the zero point.
CAUTION
A reading under zero is suppressed with the 10% FS suppression.
A reading that is 10% FS or more under zero is displayed as "-0.0", which prevents an accurate gas
detection and needs the zero adjustment.
Suppression Disabled
A fluctuation around zero is displayed as the
reading.
Suppression Enabled
A fluctuation under the setting value is hidden with zero.
(Zero suppression)
Zero Follower Off
Zero Follower On
Reading Reading
Zero point
Zero point
Time Time
* The zero drift of the sensor appears as the reading. * The zero adjustment is made periodically.