Pressure transducers capable of measuring absolute pressures at any point in the range 0 to 13 kPa and having both of the following characteristics: a. Pressure sensing elements made of or protected by aluminium, aluminium alloy, nickel, or nickel alloy with more than 60% nickel by weight; and b. Having either of the following characteristics: 1. A full scale of less than 13 kPa and an “accuracy” of better than ± 1% of full scale; or 2. A full scale of 13 kPa or greater and an “accuracy” of better than ± 130 Pa.