National Instruments SCXI -1125 用户手册

Another common use of the SCXI-1125 is to make measurements up to 
1000 VDC. Making measurements beyond ± 5 V requires use of the an 
attenuator terminal block. The SCXI-1327 and SCXI-1313A terminal 
blocks have a selectable attenuator for choosing between no attenuation or 
100:1 attenuation, which allows you to use the SCXI-1125 with up to 
300 V

rms

 when using the SCXI-1327 and up to 150 V

rms

 when using the 

SCXI-1313A.

The TBX-1316 has a fixed 200:1 attenuation, which allows you to use the 
SCXI-1125 with up to 1000 VDC, Measurement Category I.

The SCXI-1327 and SCXI-1313A also include a cold-junction sensor so 
you can combine thermocouple measurements with high-voltage 
measurements. When making signal connections, or when working with 
high-voltage signals, refer to the terminal block installation guide. If you 
are using the SCXI-1125 to measure signals with attenuation on the 
terminal block, an external bias resistor is not needed, because a bias 
resistor is already used for achieving the attenuation.

Table 5-1 lists the extended ranges of gain possible with the SCXI-1327 
and SCXI-1313A. Table 5-2 lists the extended gain possible with the 
TBX-1316.

Table 5-1.  Extended Gain and Range Using the SCXI-1327 or SCXI-1313A 

0.01

± 300 V

1

100

—

0.02

± 250 V

2

100

—

0.002

± 150 V

2

100

100

0.05

± 100 V

5

100

100

0.1

± 50 V 

10

100

100

0.2

± 25 V 

20

100

100

0.5

± 10 V 

50

100

100

2.5

± 2 V 

250

100

100