Rtd Inputs; Probe Connection; Thermocouple Inputs - Isotech TTI 7 PLUS User Maintenance Manual/Handbook

RTD INPUTS

There are 2 LEMO sockets for the Pt100 inputs and the connections are as figure below. For the best performance
we recommend 4 wire sensors, but the thermometers are able to measure with 2, 3, and 4 wire sensors.
TTI 7
PLUS
The sensors may be plugged into either channel A or B. The connection plug for the PRT sensors is LEMO type
FGG.1B.306.CLAD52
View of input socket

PROBE CONNECTION

THERMOCOUPLE INPUTS

When measuring thermocouples, care should be taken to achieve the best results. The reference junction may be set
in three different modes, the first is automatic (INT) and Pt100 sensors are attached to the upper input sockets and
monitor their temperature automatically applying the corrections. The accuracy of the internal reference is
approximately 0.3C; to achieve more accurate results, an external reference may be used (Ext). When using an
external reference the Pt100 input is used to sense the external reference temperature. The accuracy of this is as for
Pt100 measurement, 0.01C. In addition to this there will be some errors due to the configuration of the external
reference but, generally with care, it is possible to achieve better results when using the external reference mode.
Finally, the reference junction may be switched off (OFF) and in this mode the thermometer assumes a reference
junction temperature of 0C. This mode of operation is used when an external automatic reference is used such as
our Veref series. Again, using this mode of operation gives slightly better results than will be achieved when using the
internal reference.
Page 16 of 44
TTI-7 Iss.02 – 06/11