I was wondering about decoherence: Suppose a measuring apparatus measures a single quantum property (say, spin). After the actual measurement of the property has taken place, the result 'decoheres' into the apparatus until the apparatus shows the measurement result, after which it decoheres into the world. At least, I am told such. I was wondering about the physical environment of the apparatus; the material the apparatus is made of is prone to numerous influences too. However, the measurement performed is kept separate from all these influences. My question is what the difference is between these two types of decoherence is in this context, and how the measurement is kept isolated. UPDATE: Considering this, it also occurred to me that after the measurement apparatus shows the measurement result, the result is propagating according to the 'environmental' decoherence again.