I ran the MTBF calculator on this.
Part | Fail Rates per Million Hours
---------------------------------------------------------------
relay, mercury wetted contacts | 6.27
transistor, small signal, silicon | 5.73?!
resistor, ceramic compound | 1.13
I used MIL-217E-1 Reliability Prediction Stress Method, benign ground use, at 25 deg C.
I was amazed at the transistor failure rate! Damn near as bad as the relay! You might as well
save the money and leave the transistor out of the design!
kenjj