Chapter 3
NI 4350 Operation
3-22
©
National Instruments Corporation
Figure 3-10.
Multiple Transducer Connections to Analog Channels in
One Measurement Setup
The NI 4350 instrument analog inputs are protected against damage
from voltages within ±42 VDC in all ranges when powered up and
±17 VDC when powered down. Never apply voltages above these
levels to the inputs.
Caution:
To prevent possible safety hazards, the maximum voltage between any of
the analog inputs and the computer ground should never exceed ±42 VDC
when the NI 4350 instrument is powered up and ±17 VDC when the
NI 4350 instrument is powered down.
IEX+
Thermistor
Cold-Junction Thermistor (on Accessory)
Ground-Referenced Thermocouple
Floating Thermocouple
Auto-Zero
CH5+
CH5–
CH4+
CH4–
CH3+
CH2+
CH3–
RTD
CH2–
CH1+
CH1–
CH0+
CH0–
IEX–
Internal to the NI 4350
–2.5 V
20 k
Ω
Ground-Referencing: Off
Open-Thermocouple
Detection: Off
Ground-Referencing: Off
Open-Thermocouple
Detection: On
Ground-Referencing: On
Open-Thermocouple
Detection: On
Ground-Referencing: Off
Open-Thermocouple
Detection: Off
Ground-Referencing: On
Open-Thermocouple
Detection: Off
Ground-Referencing: Off
Open-Thermocouple
Detection: Off
Voltage here is
{–2.5 V + [(20 k
Ω
+ Rcjthermistor
+ Rrtd
+ Rthermistor) X 25
µ
A]}
Voltage here is
{–2.5 V + [(20 k
Ω
+ Rcjther Rrtd) X 25
µ
A]}
Voltage here is
{–2.5 V + [(20 k
Ω
+ Rcjthermistor) X 25
µ
A]}
Voltage here is
{–2.5 V + [20 k
Ω
X 25
µ
A]}
Voltage here is
{–2.5 V + [(20 k
Ω
+ Rcjthe Rrtd) X 25
µ
A]}
!
