U2781A Datasheet, PDF (38/76 Pages) Keysight Technologies – USB Modular Products

Thermocouple input mode
In thermocouple input mode, the
U2802A can acquire up to ±100 mV
input signals. Each channel includes
an instrumentation amplifier and a
4 Hz low-pass filter. The low-pass
filter removes unwanted noise from
the thermocouple wires to obtain
accurate measurement data.
Voltage input mode
Alternatively, you can select
separate voltage input modes for
each channel. The channel will be
set to bypass the amplifier and filter,
allowing up to ±10 V input signals to
be directly routed to the DAQ device
analog input. The bandwidth in this
mode is more than 500 kHz.
Zero mode
In zero mode, the positive
and negative inputs of the
instrumentation amplifier are
shorted together. The voltage
measured in this mode corresponds
to the offset voltage of the channel.
You can subtract this offset voltage
from subsequent thermocouple
mode measurements to increase
measurement accuracy. This mode
is only applicable in thermocouple
mode.
Thermocouple compatibility
The U2802A is compatible
with a wide range of standard
thermocouple types defined in
the NIST ITS-90 Thermocouple
Database. This includes types J, K,
R, S, T, N, E, and B.
Open thermocouple
detection
The U2802A includes open
thermocouple detection circuitry to
indicate the presence of an open
thermocouple.
Calibration EEPROM
The U2802A gain and offset
calibration factors for each
channel are stored in the EEPROM
during factory calibration and
can be retrieved prior to taking
measurements. This on-board
EEPROM also stores the module ID,
serial number, and date of calibration
for your reference. A section of the
EEPROM is also allocated for you to
save your calibration data.
Restoring factory calibration
Using the KMM software, you can
easily restore the U2802A calibration
data from your settings to the original
factory settings.
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