Measurement Computing DaqTemp - Manual (Page 10)

1-2 Overview & Theory of Operation 09-06-02 DaqTemp User’s Manual
Thermocouple Channels ( CH1 - CH7, CH9 - CH15 )
Each DaqTemp features on-board cold junction compensation (CJC) for direct measurement of type J,
K, T, E, N28, N14, S, R, and B thermocouples. The following table provides the temperature range for
each of these thermocouple types.
Thermocouple Temperature Ranges
T/C Type J K T E N28 N14 S R B
Temperature
Range °C -200 to
760 -200 to
1200 -200 to
400 -270 to
650 -270 to
400 0 to
1300 -50 to
1768 -50 to
1768 50 to
1780
Temperature
Range °F -328 to
1400 -328 to
2192 -328 to
752 -454 to
1202 -454 to
752 32 to
2372 -58 to
3214 -58 to
3214 122 to
3236
DaqTemps are known mainly for their input of thermocouple signals. Up to seven thermocouples [channels
1 through 7] can be connected to a thermocouple terminal block located within the DaqTemp7 and
DaqTemp7A modules. Both the DaqTemp7 and DaqTemp7A use channel 0 for CJC (cold-junction
compensation).
Thermocouple Channel Connections for
DaqTemp7 and DaqTemp7A
Thermocouple Channel Connections for
DaqTemp14 and DaqTemp14A
Up to fourteen thermocouples can be connected to a thermocouple terminal block located within the
DaqTemp14 and DaqTemp14A modules. Channels 1 through 7 are used for the first seven thermocouples
and channels 9 through 15 for the second set of seven. Both the DaqTemp14 and DaqTemp14A use two
channels for CJC (cold-junction compensation). The CJC is measured on channels 0 and 8.
The DaqTemp PCI board has 8 differential analog inputs. One of these inputs is used to measure the
thermocouple channels, leaving the other 7 for general-purpose analog input measurement. The thermo-
couple board has its own analog multiplexer that is driven by expansion channel address signals from the
PCI board. The multiplexer chooses one of 16 signals for measurement (14 thermocouple inputs and
2 CJC inputs.)
Note: Each DaqTemp thermocouple input channel can be configured for a fixed voltage gain of 100.
When in this mode, voltage can be measured in the range of ±100 mV.