Hello In patent US5376510 from Ilford Limited I was found next formula: Water 875ml Na5DTPA 37% 35ml (=13g) Sodium sulfite 120g Potassium carbonate 150g Hydroquinone 35g Dimezone S 2.5g Potassium bromide 7g Benzotriazole 0.3g Sodium hydroxide 67% 12ml (=8g) pH(1+9)=10.8 Total volume of solution isn't specified in patent. I think that its will be in range 950..1000ml. Is this Ilford PQ Universal formula? Multigrade? or something else?