KROHNE OPTITEMP TR 100-TC 100 EN - Manual (Page 19)

OPERATION
5
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OPTITEMP TR/TC 100
www.krohne.com 10/2009 - 4000630002 - MA OPTITEMP TR/TC 100 R02 en
Operation
5.1 Start-up
5.2 Normal operation
During normal operation, no settings are required on the measuring insert or transmitter.
5.3 Faults: Reasons and remedies
Short circuit or open circuit
A short circuit or open circuit, which could lead to a complete lack of or unrealistic temperature
displays, can be easily detected using a digital multimeter, for example. If this error occurs, the
insert must be replaced.
Insulation resistance too low
The insulation resistance is calculated using insulation measuring devices whose measuring
voltage is not to exceed 500 VDC (measuring inserts with Ø 6 mm / 0.236") or 250 VDC
(measuring inserts with Ø 3 mm / 0.118").
The required insulation resistance can be found in the technical data tables in the chapter
"Technical data". Insulation resistance that is too low leads to a reduced temperature display
due to the parallel connection.
Ageing
Ageing and the drifting of measured values associated with it is a characteristic of all
temperature sensors. Depending on the type and load, ageing is more or less pronounced. At
high temperatures, ageing leads to the actual temperature being larger than the displayed
value. With resistance thermometers in particular it leads to an increased resistance value
around 0°C / +32°F. The only way to be certain is to perform calibration.
If the thermometer concerned is used along with a temperature transmitter, the ageing effect is
compensated, except for a small residual error, through adequate adjustment.
Wrong thermocouple wire or compensating line
With thermocouple measuring inserts, using the wrong thermocouple wire or compensating line
results in unpredictable errors in measurement. The right compensating line connected to the
terminal block but incorrectly polarized results in a negative error corresponding to twice the
ambient temperature.
INFORMATION!
The measuring insert must first be properly installed into the thermometer assembly before it
can be started up. The tip of the measuring insert must be resting firmly on the bottom of the
thermowell. Otherwise measuring errors may occur. Incorrect wiring of the connections also
results in a fault but does not damage the measuring insert.
.book Page 19 Thursday, October 8, 2009 10:26 AM