ILX Lightwave LDT-5500B Series, Руководство пользователя, Страница: 62 / 70

Thermistor Range
48
LDT-5500B Series
C H A P T E R
B

signal is available to the thermistor inputs of the LDT-5500B Series. The LDT-
5500B Series's measurement system will over-range when the input voltage
exceeds about 4.5 volts. Figure B.1 graphically shows the lower temperature and
upper voltage limits for a typical 10 K thermistor. (A 10 K thermistor has a
resistance of 10 k

at 25
o
C). The practical temperature ranges for a typical 10 K
thermistor with the LDT-5500B Series are given in Table B.2, below. These
temperature ranges may vary from thermistor to thermistor, even though both
thermistors are nominally 10 K. This is due to manufacturing tolerances in the
thermistor, and is compensated for by determining C1, C2, and C3 (calibrating the
thermistor). The practical temperature ranges for a 10 K thermistor are also
shown as solid bars at the bottom of Figure B.1.

Table B.2 10K Thermistor Temperature Range
Figure B.1 Thermistor Temperature Range
SENSING CURRENT TEMPERATURE RANGE
10

A -30 to 30
o
C
100

A 10 to 70
o
C
THERMISTOR
VOLTAGE
5.00
4.00
3.00
2.00
1.00
0.00
-60
-40
-20
0 20 40
60
80
100
(USING TYPICAL* 10 k @ 25 C THERMISTOR)
 o
DEGREES C
10 A

100 A

* ILX default values for C1 and C2
4.50
- Denotes practical range with typical 10K thermistor
- Denotes measurable range with typical 10K thermistor