I am using an SCXI 1000 chassis with 1120 and 1327 modules to read low level (100 -800 mV) DC voltages. When one of the units that I am measuring fails, the channels are subjected to 75 VDC. I do not care about measuring the voltage when it hits 75 volts, but I need the equipment to survive.
Setting the 1327 to 100:1 attenuation and the 1120 to 10:1 gain I am able to measure all the way up to 75 volts, but the measurements are not stable at the low levels.
Keeping the 1327 at 100:1 attenuation and changing the 1120 to 100:1 gain, I am able to get stable measurements at the low levels, but the upper levels rail out at about 10 volts. I would like to use this configuration, but I wanted to make sure it would not damage my modules when they are hit with 75 volts. Is this a safe setup to use?
I am also curious as to what the maximum input voltage is to the 1120/1327 combination if the 1327 attenuation is set to 1:1.
