I have not seen this - I must get one when next at Ashwood.
For comparison, Torry Research Station say:
Smoking
Most UK salmon smokers prefer a medium cure, with a combined weight loss during salting and smoking of 16-18 per cent.
Hardwood sawdust, preferably oak, should he used to impart a pleasant flavour to the fish. The sawdust should be clean and free from wood preservatives or contaminants such as paraffin and other lubricants sometimes used on sawblades when cutting hardwoods. Sawdust containing particles of plastics laminates should never be used for smoking fish, since the fumes can be toxic.
In a mechanical kiln The kiln temperature is kept initially at 27°C and the fillets, laid on trays or hung on tenters, are smoked slowly to prevent overdrying of the cut surface and formation of a hard pellicle; residence time is usually 4-10 hours depending on size and fat content of the fillets. The kiln temperature is raised to 33°C for the last 15-20 minutes to bring oil to the surface of the fillets and give them an attractive appearance. Fillets from a 4-5 kg fish of high fat content typically require about 6 hours in the kiln. Salmon fillets generally acquire a sufficiently smoky flavour and enough colour after 5 hours; the smoke supply should then be cut off, leaving the fish to dry for the rest of the time, with the main fan and chimney fan still running.
If fillets on removal from the kiln are found to be too soft and flabby, they should either be returned at once to the kiln and drying continued, or they can be left to sweat, perhaps overnight, and then returned to the kiln for further drying at 27°C, with again a final period of 15-20 minutes at 33°C to bring out the oil.
The finished product should have a consistency rather like that of boiled ham, not too dry and fibrous, and be easily sliced.
Dry salted fillets should lose 7-9 per cent of their weight during smoking, to give the required total loss during salting and smoking of 16-18 per cent; brined fillets, which lose no weight during brining, need about twice as long in the kiln to give the same total weight loss.
In a traditional kiln Smoking time in a traditional chimney kiln is not predictable, because the process is less easily controlled, but a residence time of up to 48 hours is typical, and for large fillets during unfavourable weather the time can be as long as 60 hours. Some processors reduce the total time by hanging the fillets in a drying room heated to about 20°C for up to 24 hours before submitting them to a dense smoke. The finished product is rather more moist than that recommended earlier.
Phil