Long-term stability:
Fig7.long-term Stability
Test is finished in standard test conditions, the abscissa is observing time and the ordinate is voltage output of RL.
Instructions:
1. Preheating time
Sensor’s resistance may drift reversibly after long-term storage without power. It need to preheat the sensor to
reach inside chemical equilibrium. Preheating voltage is same with heating voltage V
H
. The suggested preheating
time as follow:
Storage Time
Suggested aging time
Less than one month
No less than 48 hours
1 ~ 6 months
No less than 72 hours
More than six months
No less than 168 hours
2. Calibration
Sensor’s accuracy is effected by many factors such as reference resistance’s difference, the sensitivity difference,
temperature, humidity, interfering gases, preheating time, the relationship between input and output is not
linear,
hysteretic and non-repetitive. For absolute concentration measurement, they need regular calibration
(one-point calibration / multi-points calibration for full scale) to ensure that the measuring value is accurate. For
relative measurement calibration is not required.
Cautions
1. Following conditions must be prohibited
1.1 Exposed to organic silicon steam
Sensing material will lose sensitivity and never recover if the sensor absorbs organic silicon steam. Sensors
must be avoid exposing to silicon bond, fixature, silicon latex, putty or plastic contain silicon environment.
1.2 High Corrosive gas