National Instruments IMAQ SCB-100, Руководство по установке

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Differential Inputs
If the MIO DAQ device is configured for differential inputs, ground-referenced signal sources
connected to the SCB-100 board do not require special components added to the SCB-100
board. For detailed information about connections to ground-referenced signal sources and
differential inputs, refer to your device documentation.
Single-Ended Inputs
The maximum voltage level generated by thermocouples is typically a few millivolts.
Therefore, for best resolution, use an MIO DAQ device with a high gain.
Thermocouples can be measured in either differential or single-ended configurations. The
differential configuration has better noise immunity, but the single-ended configuration has
twice as many inputs. The MIO DAQ device must have a ground reference because
thermocouples are floating signal sources. Therefore, you must install bias resistors if the MIO
DAQ device is in differential mode. For single-ended configuration, use the referenced single-
ended input configuration.
Cold-junction compensation with the SCB-100 is accurate only if the temperature sensor
reading is close to the actual temperature of the screw terminals. Therefore, when reading
thermocouples, keep the SCB-100 away from drafts or other temperature gradients such as
those caused by heaters, radiators, fans, and warm equipment.
Using the SCB-100 for Thermocouple
Measurements
The maximum voltage level generated by thermocouples is typically a few millivolts.
Therefore, for best resolution, use an MIO DAQ device with a high gain.
Thermocouples can be measured in either differential or single-ended configurations. The
differential configuration has better noise immunity, but the single-ended configuration has
twice as many inputs. The MIO DAQ device must have a ground reference because
thermocouples are floating signal sources. Therefore, you must install bias resistors if the MIO
DAQ device is in differential mode. For single-ended configuration, use the referenced single-
ended input configuration.
Cold-junction compensation with the SCB-100 is accurate only if the temperature sensor
reading is close to the actual temperature of the screw terminals. Therefore, when reading
thermocouples, keep the SCB-100 away from drafts or other temperature gradients such as
those caused by heaters, radiators, fans, and warm equipment.
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NI SCB-100 Installation Guide and Specifications