6 testo 6610 probes
92
6.2.6.1. Self-monitoring of cover electrode
Use in harsh ambient conditions with aggressive media in some
cases incurs the risk of damage to the sensor.
Damage to the sensor is generally reflected by incorrect readings
which occur a long time before the sensor is wrecked. If this
damage to the sensor is not spotted until too late, high costs can be
incurred due to unusable readings or machine shutdowns and
waiting times until the sensor is replaced.
Cover electrode
Bottom electrode
Substrate (ceramic
substrate for mechanical
protection)
Connections (protected
against corrosion)
Dielectric layer
The testo 6617 has a unique self-monitoring function.
This allows early detection of damage to the sensor, e.g.:
• Mechanical damage (e.g. scratches)
• Damage from aggressive gases (e.g. acids in aerosol form)
• Swelling or detachment of polymer layer due to effects of
solvents
Once the self-monitoring reaches the specific limit value, the probe
warning message "Sensor early warning" is issued.