KROHNE OPTITEMP TT 30 C-R EN - Manual (Page 30)

5
OPERATION
30
OPTITEMP TT 30 C/R
www.krohne.com 11/2012 - 4000753302 - MA OPTITEMP TT 30 C/R R02 en
5.3 SmartSense function
The in-head transmitter uses the measuring sensors (needs one additional wire in sensor) to
monitor permanently the isolation resistance of the sensor and of the sensor leads. This function
is called "SmartSense" and it is possible in combination with a sensor of the type Pt100 (3-wire
connection) and with thermoelements. The "SmartSense" function is important because an
isolation resistance which is too low creates an incorrect measuring value and thus a faulty
output.
If the transmitter shows a low isolation resistance, the "SmartSense" function allows to set the
output to a predefined value. You can set the function with the help of the PC configuration
software, in the Input tab, select:
Connection: 3w+Low Isolation for Pt100 or Cold Junction Comp.: Yes+Low Isolation for
thermocouple.
5.4 Temperature difference measurement
The transmitters are able to measure the temperature difference between two 2-wire connected
Pt100 sensors, T1 – T2. T1 must always be equal or greater than T2. Select this function in the
connection window of the input folder.
For temperature difference measurements you have to deactivate the sensor break function, i.e.
it must have the setting "Sensor break = None". You can set the function with the help of the
PC configuration, for further information refer to
Configuration with a PC on page 27.
5.5 Sensor break monitoring
The transmitter is able to determine a sensor break/short circuit with the help of a pulse signal.
This signal may interfere with electronic temperature calibrators. To switch off the pulse signal,
you have to choose the setting "Sensor break = None". You can set the function with the help of
the PC configuration, for further information refer to
Configuration with a PC on page 27.
.book Page 30 Friday, November 9, 2012 3:50 PM