Accurate, repeatable measurement of humidity is mandatory for processes that use vapor as a heat source to facilitate drying. The drying process can consume significant amounts of fuel in order to operate the dryers. Therefore, proper control can reduce operating expenses and optimize the process as well. The EXAxt ZR402 analyzer features the industry's latest technological advances such as, easy-to-read, simple-to-use, LCD touch screen operation; real-time trend graphing of process variables; two user configurable analog outputs; and, three user configurable measurement parameters. .