<Tr> <Th> warmed capacitive sensor </Th> <Td> air / gases </Td> <Td> − 15 to 50 </Td> <Td> moderate to low </Td> <Td> 2 to 0.05 Hz (temp dependant) </Td> <Td> medium to high </Td> <Td> prone to becoming saturated / contaminated over time </Td> </Tr> <Tr> <Th> resistive sensor </Th> <Td> air / gases </Td> <Td> − 10 to 50 </Td> <Td> moderate </Td> <Td> 60 seconds </Td> <Td> medium </Td> <Td> prone to contamination </Td> </Tr> <Tr> <Th> lithium chloride dewcell </Th> <Td> air </Td> <Td> − 30 to 50 </Td> <Td> moderate </Td> <Td> continuous </Td> <Td> medium </Td> <Td> see dewcell </Td> </Tr> <Tr> <Th> Cobalt (II) chloride </Th> <Td> air / gases </Td> <Td> 0 to 50 </Td> <Td> high </Td> <Td> 5 minutes </Td> <Td> very low </Td> <Td> often used in Humidity indicator card </Td> </Tr>

Why is water vapour not an ideal gas