"www.mdbg.net" mentions classifiers for almost all Chinese nouns. But there have been some cases where it doesn't suggest any classifiers. Examples are: 电阻器:resistor 电容器:capacitor 计算器:calculator
I thought to myself, maybe because all these words end in 器. So the classifier for 器 which is 台, would be the appropriate classifier for all the three mentioned words. Is it correct to deduce the classifier of a compound noun from the last character of that word?