Справочник Пользователя для National Instruments NI 9472

For Zone 2 applications, install a protection 

device between the V

sup

 and COM terminals on the 

NI 9472/9474. The device must prevent the input 
V

sup

-to-COM voltage from exceeding 42 V if there is a 

transient overvoltage condition.

This equipment has been evaluated as EEx nC IIC T4 equipment 
under DEMKO Certificate No. 03 ATEX 0324020X. Each module 
is marked 

 II 3G and is suitable for use in Zone 2 hazardous 

locations. If you are using the NI 9472/9474 in Gas Group IIC 
hazardous locations or in ambient temperatures of 
–40 °C

≤ Ta ≤ 70 °C, you must use the device in an NI chassis that 

has been evaluated as EEx nC IIC T4, Ex nA IIC T4, or 
Ex nL IIC T4 equipment.