Glossary - ProMinent DULCOMETER Assembly And Operating Instructions Manual

Glossary

23 Glossary
Glass break detection
[ON] / [OFF] : Switches glass break detec‐
tion of the pH sensor
[OFF] . If the controller
factory setting is
[ON] , it displays an error
has the setting
message if an error is detected.
The glass break detection device monitors
a pH sensor to detect whether the sen‐
sor's glass body is broken. If a break
exists in the glass body, the resistance of
the pH sensor falls below approximately
2 mega-Ω. The controller can interpret this
resistance change. The controller gener‐
ates an error message and control is
stopped. This error cannot be acknowl‐
edged.
The resistance (ohms) of the pH sensor
also falls if the process temperature
increases. Once the process temperature
is approx. > 60 °C the detection threshold
of 2 mega-Ω is reached. For process tem‐
peratures > 60 °C a grass break is
detected even though no glass break
exists. So that an error alarm is avoided,
glass break detection must be switched
off at process temperatures > 60 °C.
Glass break detection
[ON] / [OFF] : Switches glass break detec‐
tion of the pH sensor
[OFF] . If the controller
factory setting is
[ON] , it displays an error
has the setting
message if an error is detected.
[Glass break detection]
The function
increases the safety of the measuring
point.
152
[ON] or [OFF] . The
[ON] or [OFF] . The
Cable break detection
[ON] / [OFF] : Switches cable break detec‐
tion of the coaxial cable
The factory setting is
troller has the setting
alarm message if an error is detected.
The cable break detection device monitors
a pH sensor with a coaxial connection
cable to determine whether a break exists
in the coaxial connection cable. If a break
exists in the coaxial connection cable, the
resistance increases enormously to
approximately 1 giga-Ω. The controller
can interpret this resistance change. The
controller generates an error message
and control is stopped. This error cannot
be acknowledged.
The glass membrane of the pH sensor
becomes highly resistant when the
process temperature falls. Once the
process temperature is approx. < 15 °C
the detection threshold of 1 gig-Ω is
reached. For process temperatures
< 15 °C a cable break is detected even
though no cable break exists. So that an
error alarm is avoided, cable break detec‐
tion must be switched off at process tem‐
peratures < 15 °C.
Cable break detection
[ON] / [OFF] : Switches cable break detec‐
tion of the coaxial cable
The factory setting is
troller has the setting
alarm message if an error is detected.
[Cable break detection]
The function
increases the safety of the measuring
point.
[ON] or [OFF] .
[OFF] . If the con‐
[ON] , it displays an
[ON] or [OFF] .
[OFF] . If the con‐
[ON] , it displays an