Data Translation DT9871, User Manual

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Specifications
121
Isolation and Protection Specifications
Table 17 lists the isolation and protection specifications for the analog input subsystem on the
DT9871, DT9871U, DT9872, DT9873, and DT9874 instruments.
Table 17: Isolation and Protection Specifications
Feature Specifications
DT9871U, DT9871, and DT9874 Thermocouple Channels Overvoltage
Protection (Power On/Off)
Pin 2 referenced to pin 3:
Pin 2 and 3 referenced to earth ground: ±40 V
30 VAC, 42.4 Vpk, 60 VDC max.
a
a. These pins are functionally isolated for a maximum of 30 VAC, 60 VDC Ch-Earth, verified by a 500 Vpk withstand.
DT9872 and DT9874 RTD Channels Overvoltage Protection (Power
On/Off)
Pin 1 referenced to pin 4:
Pin 2 referenced to pin 4:
Pin 3 referenced to pin 4:
Pin 1, 2, or 3 referenced to earth ground: ±4 V
b
±40 V
±20 V
30 VAC, 42.4 Vpk, 60 VDC max.
a
b. Determined by internal protection diodes to the power supply. No damage occurs if current is limited to ±10 mA.
DT9873 and DT9874 Voltage Input Channels Overvoltage Protection
(Power On/Off)
Pin 1 referenced to pin 3:
Pins 1 and 3 referenced to earth ground: ±30 VAC, 42.4 Vpk, 60 VDC max.
a
30 VAC, 42.4 Vpk, 60 VDC max.
a
ESD protection per standard EN61000-4-2:2009 (see page 125 for more)
Arc:
Contact: 8 kV
4 kV
Isolation voltage to the host computer 30 VAC, 42.4 Vpk, 60 VDC max.
a
Channel-to-channel isolation 30 VAC, 42.4 Vpk, 60 VDC max.
a