H5800 is a handheld microprocessor-based device for relative-humidity measurement in air and non-aggressive gases, designed to operate with COMECO’s RH probes. With the help of a Pt1000 sensor build in the RH probe, H5800 compensates probe temperature drift and indicates medium temperature. The device is equipped with a 4-digit display providing a resolution of 0.1. Two modes of operation – measurement of relative humidity and measurement of medium temperature in degrees Celsius or Fahrenheit – are available. Dew-point, absolute humidity, mixing ratio, and enthalpy can also be measured through calculation. H5800 is programmed and controlled through a folio-type keyboard providing high degree of environmental protection. The device is offered with 2 alkaline or rechargeable 1.5 V AA batteries and features a special automatic-battery-control function. The numerous features of H5800, along with its high accuracy and low consumption, make it a widely applicable measurement instrument.