Tracey,
The other six boards don't seem to exhibit the large offset value on channel #3. They all fall within spec.
Does the boost transistor help to reduce the amount of temperature induced drift in the part and perhaps help protect the AD5422 from getting blown out if extreme transients occur on the field wiring?
Looking at Figure 1. in the data sheet. Is there any way that the internal resistor R3 can be damaged by transients occurring on the boost transistor emitter node?
One of our applications switches the unloaded output to a 250 ohm resistor using a reed relay.
Regards,
Steve