Thanks re the TDI forum link, the DPF pressure sensor cost AUS $100 - fitting another ~$100 - you have to take the air box out to get to it.
I have had a 'flush', several 'regenerations' so far. A good look over other parts of the car - intake system etc.
The OBD gives a pressure fault, the original manufacturers DPF (Merc) part is about $3,000.
I travel quite a bit to the country - most weeks I will do about 200-300km at ~100km/hr so its not the usual driving style problem. To be fair the car has done ~160,000km in 6 yrs - so to be honest it is probably just 'buggered'. There is a local AUS guy who makes some equivalent DPFs - I haven't heard back from them if they do my model.
Hopefully it's just a clogged pressure sensor then. IIRC, you may even be able to clean this out as well.
Oh, as per cost of the DPF, they go for ~$1300 here (VW P/N; not aware of any aftermarket at this time), so it sounds like importing one would be a less expensive alternative.
What actually id the difference between the 27 and the 27/FM?
It was designed specifically for the military. The meter itself does have true RMS, unlike it's civilian counterpart. But it also included an HV probe (6kV?), and a custom case to fit it all IIRC (DMM, HV probe, standard probes, spare battery).