DPF Sensor advice& learning please

So am trying to learn and understand the workings of my cars dpf and would greatly appreciate any advice or guidance please. 

This is because of late the dpf is regening alot more than it use to. 

I have DPF VAG app to help me monitor the health/performance of the DPF. 

The oil ash is very high and is close to it's limit before I have to take action. 

Am assuming that's why it's regening alot more than what it's use to ??? 

All the information on the app got me very curious to know the full workings of the dpf and got me wanting to know if all the sensors are actually ok ?? 

How many related sensors are there ?? I know there is a diff sensor for before and after pressure. I know there is 2 oxygen sensors also one in dpf and one in exhaust. 

Is there a temperature sensor also ??  

A sensor for reading the soot to ??? 

I have also heard talk of vaporisers in connection with dpf will mine have one of those to ?? 

Sorry if I come across clueless am just eager to learn about the workings of a part that as am sure you know is remarkably expensive to replace. 

Thanks in advance for reading and any advice is greatly appreciated 👍 👍