If you have a chare coupled device it's in pC/g typically, and you dial it in on the charge amp.
More generally, yes, you can use different sensitivities, but if you use a different model of accelerometer then it may have a different noise floor, max output, frequency response, and of course mass.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.