What is the maximum number of samples that can be evaporated using the GreenHouse Blowdown? The GreenHouse Blowdown evaporates samples by blowing inert gas through pins onto your samples – one pin per sample. There are three types of pin plate available: RR99672: GreenHouse Long Blowdown Pin Plate 6 x 4 RR99673: GreenHouse Blowdown Pin Plate 6 x 4 RR99674: GreenHouse Blowdown Pin Plate 4 x 2 The maximum number of samples is therefore 24. You can use the long or short pin plates as appropriate for your sample volumes / vessels.