■
The shield grounding methodology can vary depending on the application.
■
Refer to your thermocouple documentation or the thermocouple wire spool
to determine which wire is the positive lead and which wire is the negative
lead.
Minimizing Thermal Gradients
Changes in the ambient air temperature near the front connector or a thermocouple
wire conducting heat directly to terminal junctions can cause thermal gradients.
Observe the following guidelines to minimize thermal gradients and improve the
system accuracy.
■
Use small-gauge thermocouple wire. Smaller wire transfers less heat to or
from the terminal junction.
■
Run thermocouple wiring together near the TB-9214 to keep the wires at the
same temperature.
■
Avoid running thermocouple wires near hot or cold objects.
■
Minimize adjacent heat sources and air flow across the terminals.
■
Keep the ambient temperature as stable as possible.
■
Make sure the NI-9214 terminals are facing forward or upward.
■
Keep the NI-9214 in a stable and consistent orientation.
■
Allow the thermal gradients to settle after a change in system power or in
ambient temperature. A change in system power can happen when the
system powers on, the system comes out of sleep mode, or you insert/remove
modules.
■
If possible, use the foam pad in the TB-9214 opening to restrict airflow
around the terminals.
Wiring the TB-9214
What to Use
■
TB-9214
© National Instruments
9
NI-9214 Getting Started
