Self-Monitoring Of Cover Electrode - TESTO 6381 Instruction Manual

6 testo 6610 probes
Application
• Monitoring and regulating industrial humidity processes
involving corrosive media (apart from high-humidity processes)
with the exception of applications with HCL, HF and other acids
and acidifiers in larger concentrations (SO
• Meeting the top accuracy requirements
• Applications for which a sturdy metal housing is required
6.2.7.1.

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.
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.
122
This probe does NOT have a longer life with exposure to
aggressive media than the testo 6613, for example.
However, early warning of damage to the sensor is given
so that machine failures can be avoided.
, SO , NO
2 3
1 Cover electrode
2 Bottom electrode
3 Substrate (ceramic
substrate for mechanical
protection)
4 Connections (protected
against corrosion)
5 Dielectric layer
)
2