Initial Sensor Drift And Active Burn-In; Figure 2 Jumper Confi Guration For Calibration Type & Range Selection - Michell Instruments XZR200 User Manual

INSTALLATION
Using the jumper settings shown below, both the measurement range and the calibration
option can be set. The following options are available:
Measuring range: 0-25% or 0-100%
Calibration: Auto cal or manual calibration
Figure 2
2.2

Initial Sensor Drift and Active Burn-In

NOTE: In the fi rst 200 hours the sensor output can drift by up to ±3%.
This is due to a number of factors including:
• impurities in the Zirconium Dioxide migrating to the surface of the platinum
electrode bond which alters the catalytic properties.
• heater coil ageing.
• the internal stainless steel surface of the cap becoming less refl ective due
to thermal oxidation.
Regular calibration removes the effect of initial sensor drift as the sensor output is
constantly re-referenced against the known calibration gas. However, if regular
calibration is not possible and the output is required to have stabilized prior to use in
the application then it may be necessary to actively burn-in the sensor.
Active burn-in involves operating the sensor normally in a controlled atmosphere where
the exact PPO
and the PPO
2
The level of stability required will be dependent on the application specifi cations.
However, in general the output can be considered stable when the value has varied by
less than ±0.2% of reading in the previous 48 hours.
When performing an active burn-in, measurements should be taken at regular intervals
and the environmental temperature should also be kept constant to negate any
temperature dependence the sensor output may exhibit.
4
JUMPER LINKS
Sensor LED
Jumper Confi guration for Calibration Type & Range Selection
is known. If this is normal air then all weather data must be recorded
2
calculated.
XZR200 User's Manual
AUTO CAL
MANUAL CAL
100% O RANGE
2
25% O RANGE
2
97337 Issue 4, July 2018