It is certain to avoid cooling point in the channel, in case some outflow with high boiling point condensate in halfway to affect quantitative results.
务必避免通道中有冷却点存在，否则会使一些高沸点流出物在中途冷凝而影响质谱定量结果。
2
A short passage of return pipe on the water discharge pipe may be placed to prevent outside air into evaporator and facilitate the outflow of condensate.