Of all common environmental parameters, humidity is perhaps the least understood and most difficult to
measure. The most common electronic humidity detection methods, albeit highly accurate, are not obvious
and tend to be expensive and complex (See Box). Accurate humidity measurement is vital to a number of
diverse areas, including food processing, paper and lumber production, pollution monitoring and chemical
manufacturing. Despite these and other applications, little design oriented material has appeared on
circuitry to measure humidity. This is primarily due to the small number of transducers available and a
generally accepted notion that they are difficult and expensive to signal condition.