Installation; Temperature Sensor Output And Accuracy - National Instruments SCXI-1322 Installation Manual

Installation

To connect the terminal block to the SCXI module front connector, perform the following steps:
1. Connect the module front connector to its mating connector on the terminal block.
2. Make sure that the module top and bottom thumbscrews do not obstruct the rear panel of the
terminal block.
3. Tighten the top and bottom screws on the back of the terminal block to hold it securely in place.

Temperature Sensor Output and Accuracy

The SCXI-1322 temperature sensor outputs 1.91 to 0.58 V from 0° to 55° C and has an accuracy of
±0.65° C over the 15° to 35° C range and ±0.85° C over the 0° to 15° and 35° to 55° C ranges
Note: If you are using National Instruments software such as LabVIEW or LabWindows, you
do not need to read this section.
To determine the temperature, use the following formulas:
T(°C) = T - 273.15
K
where T is the temperature in kelvin and is determined by the Steinhart-Hart equation:
K
=
[
T
K (
a + b lnR
T
a = 1.295361 x 10
b = 2.343159 x 10
c = 1.018703 x 10
= resistance of the thermistor in Ω
R
T

V
= 5,000

R
T
2.5 − V

V = output voltage of the temperature sensor
TEMPOUT
[ ]
T(°C)
T(° F) =
5
where T(°F) and T(°C) are the temperature readings in degrees Fahrenheit and degrees Celsius,
respectively.
Note: Use an average of a large number of samples to obtain the most accurate reading. Noisy
environments require more samples for greater accuracy.
1
The temperature sensor accuracy includes tolerances in all component values, effects caused by temperature, loading,
self-heating, and temperature gradients.
SCXI-1322 Terminal Block Installation Guide
1
]
) ( )
3
+ c lnR
T
-
3
-
4
-
7

TEMPOUT


TEMPOUT
9
+ 32
6 © National Instruments Corporation
1 .